Infantry Discussion Thread part 11: Gallas Razor edition.

[Crookfur]

Sitting facing in has a few advantages: faster entrance and egress as mentioned, improved comfort as it maximises the available leg room and at worse your legs are squashed up next to your m8s rather than solid vibrating metal and finally it improves moral and communication amongst the dismounts as they can see and talk to each other a bit easier. Inward facing seating is also generally easier to fold up or stowaway if you need the load space for other things.

Biggest plus to outward seating is that it allows better external vision under cover and makes it easier to use firing ports from a seated position but there is a definite line of thought against firing ports.

[The Manticoran Empire]

Sitting facing in has a few advantages: faster entrance and egress as mentioned, improved comfort as it maximises the available leg room and at worse your legs are squashed up next to your m8s rather than solid vibrating metal and finally it improves moral and communication amongst the dismounts as they can see and talk to each other a bit easier. Inward facing seating is also generally easier to fold up or stowaway if you need the load space for other things.

Biggest plus to outward seating is that it allows better external vision under cover and makes it easier to use firing ports from a seated position but there is a definite line of thought against firing ports.

I've done some research on IFVs (not enough to be an expert) and from what I've read, it appears that the Firing Ports fell out of favor because they weakened the armor overall and weren't accurate enough to justify the loss in protection.

[Republic of Penguinian Astronautia]

Also, according to what I can find, the ampv is going to seat 6 soldiers, yet has 78% more interior volume than the m113, which could seat 11. Six isn't a full squad. Why can't it house all nine troops?

[Purpelia]

Also, according to what I can find, the ampv is going to seat 6 soldiers, yet has 78% more interior volume than the m113, which could seat 11. Six isn't a full squad. Why can't it house all nine troops?

m113 was rated for 11 people with 60's gear. Gear has gone up in bulk since than. So have men.

[The Akasha Colony]

Also, according to what I can find, the ampv is going to seat 6 soldiers, yet has 78% more interior volume than the m113, which could seat 11. Six isn't a full squad. Why can't it house all nine troops?

The original Turretless Bradley proposal removed the Bradley turret but did not extend the seating benches forward into the space where the turret was located, thus the seating is the same as the fully-armed Bradley. Which in turn has a lower seating capacity because it has a big two-man turret.

This is fine because AMPV isn't actually meant to be a troop carrier, it's a general-purpose carrier. The combat infantry transport role has already been filled by the original Bradley and AMPV is meant to take over the support tasks which are still reliant on the old M113 platform. There are still a lot of M113s that get attached to HQ units to carry staff around or general cargo but not whole infantry squads, and this is the role the GP variant AMPV is meant to fill.

[The Manticoran Empire]

Also, according to what I can find, the ampv is going to seat 6 soldiers, yet has 78% more interior volume than the m113, which could seat 11. Six isn't a full squad. Why can't it house all nine troops?

Because it doesn't need to. Plus, there is really no reason why six men can't be a full squad.

[Danternoust]

In practice, this probably means people go on the ship nearly naked (a jumpsuit and a small luggage of personal belongings, like e-readers or photo albums) and can requisition more detailed personal belongings from the in-situ production facilities onboard. If you want a guitar, you can spend so many joules you gathered going about your job to get one, and that consumes a certain percentage of your allowed mass of leisure goods, or something. You aren't bringing a guitar with you, of course, because your mass allowance won't allow it. The "guitar" would rather be stored on the ship as an allocated amount of feedstock mass for the production center.

If you design machinery, and the machinery has access to unlimited energy and feedstock, how much can you be paid per hour?

If you live on a world with nuclear energy, the max capacity with environmentally sustainable practices is limited by heat dissipation into the void of space (at least before proteins cease to function near the equator).

It really depends if you are willing to pay the ~$100 per kilogram price for luggage, if Musk's proposals are remotely possible.

Naturally of course compound economic growth means that GDP/capita would be $200,000/year, allowing you to take your motor vehicle into space, if you so choose.

[Republic of Penguinian Astronautia]

OTOH there's only like a dozen people in mat's Serious NSDiscord.

Anytime someone tries to do anything for the betterment of UVR's (mat adding "serious" discussion, TT using everyone, Techno throwing Ford's gigapanzers in the trash bin) they get demodded.

e:

Probably because the French did a very similar thing to it:

TBF the FELIN sight is about half a dozen times superior to FWS Individual, except for being heavy, but it's basically a "PAS-13B Heavy + greeblies" like a LRF and EO WFOV camera. The French being "smart" enough to outsource the weight of the IIR and NIR cameras to the rifle sight/your forearms instead of the helmet/your neck.

FWS-I is just the US Army giving up on ever having any decent chance at getting Land Warrior into production for the next 20 years. I suppose because "exceeding Russian/Chinese developments that much further" is "escalatory" or something and they want to handicap themselves in the future hyperwar. Meanwhile the Chinese will probably have made half a million FELIN copies through the 20s as USA withdraws from Eurasia and pan-Eurasianism becomes a thing, except it's French/Russians using the Chinese to contain the USA/British instead of the USA/British/French using the Chinese to contain the Russians. Franco-Russian Friendship Treaty alive in 202X.

Ogreverse when. Real life is just the prequel to 2300 AD.

What about Germany?

[Gallia-]

and the machinery has access to unlimited energy and feedstock,

What environment is unlimited in any sense of the word?

That's a rhetorical question, the answer is "none".

if Musk's proposals are remotely possible.

Musk can't even make an automobile factory, which is something so simple that literally every country with electricity can do it.

Going to Mars in person is so difficult that not even the greatest economic powers of the world have managed it.

[Kassaran]

Musk can't even make an automobile factory, which is something so simple that literally every country with electricity can do it.

Umm, what?

[Gallia-]

Musk can't even make an automobile factory, which is something so simple that literally every country with electricity can do it.

Umm, what?

What is this supposed to prove, exactly? A company that organizes a factory under tents is less a factory and more a ramshackle display. Simply put, Tesla has no good industrial engineers who know how to actually mass produce stuff. It lost $1 billion in 2018 and is suffering mass layoffs and poor production today. Literally the only reason it's still around is because of billions of dollars of subsidies from the government and prior investors' cult-like worship of its techno-optimist philosophy. It's an incompetent auto company that is more or less surviving because it's about as good at PR as British Aerospace and it's receiving titanic subsidies. If it had zero subsidies it wouldn't exist at all. If it had to pay those subsidies back its debt load would be even higher.

What's happening right now is an expected demand surge that will taper off around Q2 19 and it's back to business-as-usual for TSLA. Especially true if Trump turns up the trade war even higher by attacking companies that haven't shifted production out of China or are actively collaborating with the Politburo, like Google and Tesla.

Tesla isn't in imminent danger of collapsing, right now, but it will probably forever be a basket case until the entire board is wiped out and replaced by people who know what they're doing, i.e. can make a factory that works.

It's making automobiles sure, but only by a brute force model of having a load of parallel production lines that are all individually inefficient, rather than an actually good production line, because it is/was overly automated. They've started to address this but they still have a lot to learn and very little time to learn it. What they learned with the excessive automation is what GM and others learned 30 or 40 years ago. When BMW, GM, and Toyota get their next-gen EVs out, Tesla will be done, unless it's somehow going to go from "1990s GM" tier to "2010s Toyota tier" in a year, which is very unlikely unless it snatches all the industrial engineers from Toyota or something.

What will more than likely happen is TSLA is bought by the Politburo/Communist Party agents who own NEVS EV, or Tencent, and US Congress may block their purchase on national security grounds so Toyota or GM snaps them up for pennies, or Tesla's assets are split between "Eurasian" and "American" with the Chinese based factories going to the Communist Party (and being raided for every scrap of technology) while the American plants go to someone trustworthy and not an enemy. People like to talk about "Google" or "Apple" being the buyer of a possible bankrupt Tesla, but those guys are just Tencent with a US flag for a face, and as much an enemy, so I think Toyota or GM are the real options there.

It will still be "Tesla", but it'll be a brand/division with pretty much everyone swept aside and replaced with competent people who run it as a real car company, and it shakes off all pretenses of Musk's archaic techno-optimist delusions.

[Purpelia]

As I find my self saying all to often these days it has a point. It ain't a pretty point, but it has it.

[Morrdh]

So the EM-2 rifle....

Something I'm thinking of having my military adopt, but in the .270 British cartridge as that round was identified as the preferred option and the larger .280 appears to have been to try and attract the Americans.

Read the report from the 1950s US Trails which highlighted some issues, though some accuracy and reliability issues were reported it is stated that a.) the rounds used were suspect and didn't appear to have been filled properly and b.) there were fewer malfunctions when tested with the British supplied lubricant.

Though for the other issues, I've identified them and posted my own solutions;

Breech block assembly gave excessive malfunctions and breakages - EM-2 uses a similar flapper lock like the Gewhr 43 and Degtyaryova series of Soviet weapons, would it be better to switch to a different system like a rotating lock found on the AK and M16 families?

User getting burns when contacting the gas canister - the gas canister appears to be exposed like the FAL prototype, so I'm thinking extending the handguard up and over the gas canister like it is on production FALs...though probably replace later on with a SA80 style cover/handguard

Not sure on the accuracy problems on automatic fire, the rifle was the best out of the three rifles for that category during the trail. Forgotten Weapons got to fire the rifle in .280 British, but didn't say which version of the round used (later model rounds were uprated to be closer to 7.62mm NATO). Using the smaller cartridge and a little bit of weight increase could, in theory, make it less of an issue.

There were issues reported with the trigger link system, though apparently thats always the weakest link on a bullpup design and I'm not sure what the solution would be. You get to see the linkage system in the video beyond at round the 18:30 minute mark.

https://www.youtube.com/watch?v=fcYj2SpUHvE

Also, found a photoshop of the EM-2 of what it might've looked like in the '80s, pretty close to what I imagine. Envision a progression from the EM-2's original sight through to SUIT (seen a pic of this), then SUSAT and probably more modern sights.

Anyone got any thoughts or ideas on this?

[The Manticoran Empire]

So the EM-2 rifle....

Something I'm thinking of having my military adopt, but in the .270 British cartridge as that round was identified as the preferred option and the larger .280 appears to have been to try and attract the Americans.

Read the report from the 1950s US Trails which highlighted some issues, though some accuracy and reliability issues were reported it is stated that a.) the rounds used were suspect and didn't appear to have been filled properly and b.) there were fewer malfunctions when tested with the British supplied lubricant.

Though for the other issues, I've identified them and posted my own solutions;

Breech block assembly gave excessive malfunctions and breakages - EM-2 uses a similar flapper lock like the Gewhr 43 and Degtyaryova series of Soviet weapons, would it be better to switch to a different system like a rotating lock found on the AK and M16 families?

User getting burns when contacting the gas canister - the gas canister appears to be exposed like the FAL prototype, so I'm thinking extending the handguard up and over the gas canister like it is on production FALs...though probably replace later on with a SA80 style cover/handguard

Not sure on the accuracy problems on automatic fire, the rifle was the best out of the three rifles for that category during the trail. Forgotten Weapons got to fire the rifle in .280 British, but didn't say which version of the round used (later model rounds were uprated to be closer to 7.62mm NATO). Using the smaller cartridge and a little bit of weight increase could, in theory, make it less of an issue.

There were issues reported with the trigger link system, though apparently thats always the weakest link on a bullpup design and I'm not sure what the solution would be. You get to see the linkage system in the video beyond at round the 18:30 minute mark.

https://www.youtube.com/watch?v=fcYj2SpUHvE

Also, found a photoshop of the EM-2 of what it might've looked like in the '80s, pretty close to what I imagine. Envision a progression from the EM-2's original sight through to SUIT (seen a pic of this), then SUSAT and probably more modern sights.

(Image)

Anyone got any thoughts or ideas on this?

I'm not very familiar with it but what I have seen of it is promising. Your solutions to the issues seem solid.

[Immoren]

[Gallia-]

Strike Witch unit should be the helicopter symbol with a star wand poking out instead of a arrow.

[Manokan Republic]

Also, according to what I can find, the ampv is going to seat 6 soldiers, yet has 78% more interior volume than the m113, which could seat 11. Six isn't a full squad. Why can't it house all nine troops?

This is a good question that I can't find a good answer to; other than the fact that the turret has rounds that extend in to the passenger cabin as a technical matter. The width of a person is under 2 feet, so by adding four feet to the vehicle, they could easily add 4 extra soldiers for a total of 10, with two on each side. Why not do this? I'm not really sure, other than I guess they really don't care about the extra soldiers, or think that very specific purpose driven vehicles are a good idea. They might be holding out for turrets that don't extend in to the passenger cabin, but even then it seems weird.

Unless the military is actually going for a 6 man team in the future, this seems like a step backwards, not to mention we still don't have a replacement for our nearly 50 year old APC's.

[Manokan Republic]

So the EM-2 rifle....

Something I'm thinking of having my military adopt, but in the .270 British cartridge as that round was identified as the preferred option and the larger .280 appears to have been to try and attract the Americans.

Read the report from the 1950s US Trails which highlighted some issues, though some accuracy and reliability issues were reported it is stated that a.) the rounds used were suspect and didn't appear to have been filled properly and b.) there were fewer malfunctions when tested with the British supplied lubricant.

Though for the other issues, I've identified them and posted my own solutions;

Breech block assembly gave excessive malfunctions and breakages - EM-2 uses a similar flapper lock like the Gewhr 43 and Degtyaryova series of Soviet weapons, would it be better to switch to a different system like a rotating lock found on the AK and M16 families?

User getting burns when contacting the gas canister - the gas canister appears to be exposed like the FAL prototype, so I'm thinking extending the handguard up and over the gas canister like it is on production FALs...though probably replace later on with a SA80 style cover/handguard

Not sure on the accuracy problems on automatic fire, the rifle was the best out of the three rifles for that category during the trail. Forgotten Weapons got to fire the rifle in .280 British, but didn't say which version of the round used (later model rounds were uprated to be closer to 7.62mm NATO). Using the smaller cartridge and a little bit of weight increase could, in theory, make it less of an issue.

There were issues reported with the trigger link system, though apparently thats always the weakest link on a bullpup design and I'm not sure what the solution would be. You get to see the linkage system in the video beyond at round the 18:30 minute mark.

https://www.youtube.com/watch?v=fcYj2SpUHvE

Also, found a photoshop of the EM-2 of what it might've looked like in the '80s, pretty close to what I imagine. Envision a progression from the EM-2's original sight through to SUIT (seen a pic of this), then SUSAT and probably more modern sights.

(Image)

Anyone got any thoughts or ideas on this?

It's a really cool idea, and I think the EM-2 would have been a big leap forward in military technology if it was ever adopted. A more accurate aerodynamic bullet is a great idea for a lot of reasons, and as range and weight is very important for a machine gun, a lighter weight round that could maintain the same range as the 7.62mm NATO, and more or less same power at longer ranges, would have been fantastic. Today, a 6.5mm Grendel more or less can fulfill the role of a .280 or .270 British, and is more aerodynamic and accurate as well as easily adapted to fire in 5.56mm rifles, while something like the 6mm aluminum (or a modernized version of it) more closely achieves the ideal of long range, lightweight, moderate power round. From a practical standpoint it would be easy to convert the SA80 to firing 6.5mm grendel rounds, while from an ideal standpoint the 6mm aluminum would be the lightest weight, albeit a little bit weaker (although a modernized version in theory could be more powerful). The aluminum cased guns tended to either need insulation in them or catch on fire too easily, an issue easily resolved with a coating on the aluminum (such as thin polymer) or a change in the bolt/barrel material so galling of the aluminum is reduced. They were also a little bit weaker.

The .280 british series of rounds to my knowledge were rather low velocity given the larger 9.1 gram bullet, less aerodynamic (with a B.C. of about .4), and 21.5 grams, which is only marginally lighter than a 7.62mm NATO at 25.5 grams, or 20% lighter, with 2800 joules. A 6.5mm grendel has a BC of .5 with an 8 gram bullet, a higher velocity, and is 16.3 grams, about the same as an Ak-47, and substantially lighter than the 7.62mm, allowing for about 70% more ammunition to be carried, or 20-30% less than a 5.56mm, with 2600 joules. The 6mm aluminum in theory is as light or lighter than a 5.56mm, with a minimum of about 10.5 grams, allowing evne more rounds to be carried, with potentially a BC of .5 or .6 depending on what bullet you use, but it was notably weaker than both, at only 2000 joules vs. 2600 and 2800. With modern gunpowder, it is possible to achieve more power in the same case, with the .25-45 sharp for example using a 5.56mm case but achieving 2350 joules vs. 1800 joules or 30% more power, so it is conceivable you could improve it's capabilities quite a bit. The .280 british is by no means bad, it is a heavier, higher recoil, and slightly shorter range option than the other two or in comparison to other low-drag intermediate bullet designs.

That being said! All of the proposed changes you've presented make sense, and if you want the .280 british specifically, something akin to a bullpup FAL design keeps in line with the british weapon designs while also still remaining similarity to the EM-2. A rotating bolt does make sense for small arms, in large part due to it's simplicity (with the original EM-1's being hideously complex to manufacture for example), and you could use a modernized HK416, ak-47 style etc. internal design instead. You could just say that it is a gun with a different firing mechanism in it, but looks like an EM-2. A logical reason for this might be for familiarity for troops so they can easily transition to the new rifle. I will say though that the higher power and recoil of the .280 british in comparison to say, a 5.56mm is less of an issue, largely due to things like muzzle breaks and softer recoil systems. The FN SCAR for example shoots pretty softly, as does the Tavor 7 and many other modern battle rifles, and so presumably a .280 british which is lighter and has less energy than a rifle round, it should be less.


The big thing I would say is that while 7mm rounds have good ballistic coefficients, they only achieve this with far heavier rounds than 6mm and 6.5mm rounds. A 140 grain 6.5mm can easily attain .6 BC, while a 150 grain 6.5mm round will attain .71, and a 7mm at around 140 grains is only at best maybe .5 BC, but all the figures I can find are around .4 BC. This using the G1 figures. I have figures for Hornady, but for some reason the sierra match king website is down? O.o It depends on the manufacturer but generally a 6.5mm or 6mm will be more aerodynamic and accurate for it's given weight, which is more useful with intermediate cartridges. With less power you can get a higher velocity, which is nice. I made a chart detailing a lot of this information some time ago, but it doesn't include the 6mm or .280 british, but I still figure it might be useful for a baseline comparison.

[Morrdh]

It's a really cool idea, and I think the EM-2 would have been a big leap forward in military technology if it was ever adopted. A more accurate aerodynamic bullet is a great idea for a lot of reasons, and as range and weight is very important for a machine gun, a lighter weight round that could maintain the same range as the 7.62mm NATO, and more or less same power at longer ranges, would have been fantastic. Today, a 6.5mm Grendel more or less can fulfill the role of a .280 or .270 British, and is more aerodynamic and accurate as well as easily adapted to fire in 5.56mm rifles, while something like the 6mm aluminum (or a modernized version of it) more closely achieves the ideal of long range, lightweight, moderate power round. From a practical standpoint it would be easy to convert the SA80 to firing 6.5mm grendel rounds, while from an ideal standpoint the 6mm aluminum would be the lightest weight, albeit a little bit weaker (although a modernized version in theory could be more powerful). The aluminum cased guns tended to either need insulation in them or catch on fire too easily, an issue easily resolved with a coating on the aluminum (such as thin polymer) or a change in the bolt/barrel material so galling of the aluminum is reduced. They were also a little bit weaker.

The .280 british series of rounds to my knowledge were rather low velocity given the larger 9.1 gram bullet, less aerodynamic (with a B.C. of about .4), and 21.5 grams, which is only marginally lighter than a 7.62mm NATO at 25.5 grams, or 20% lighter, with 2800 joules. A 6.5mm grendel has a BC of .5 with an 8 gram bullet, a higher velocity, and is 16.3 grams, about the same as an Ak-47, and substantially lighter than the 7.62mm, allowing for about 70% more ammunition to be carried, or 20-30% less than a 5.56mm, with 2600 joules. The 6mm aluminum in theory is as light or lighter than a 5.56mm, with a minimum of about 10.5 grams, allowing evne more rounds to be carried, with potentially a BC of .5 or .6 depending on what bullet you use, but it was notably weaker than both, at only 2000 joules vs. 2600 and 2800. With modern gunpowder, it is possible to achieve more power in the same case, with the .25-45 sharp for example using a 5.56mm case but achieving 2350 joules vs. 1800 joules or 30% more power, so it is conceivable you could improve it's capabilities quite a bit. The .280 british is by no means bad, it is a heavier, higher recoil, and slightly shorter range option than the other two or in comparison to other low-drag intermediate bullet designs.

That being said! All of the proposed changes you've presented make sense, and if you want the .280 british specifically, something akin to a bullpup FAL design keeps in line with the british weapon designs while also still remaining similarity to the EM-2. A rotating bolt does make sense for small arms, in large part due to it's simplicity (with the original EM-1's being hideously complex to manufacture for example), and you could use a modernized HK416, ak-47 style etc. internal design instead. You could just say that it is a gun with a different firing mechanism in it, but looks like an EM-2. A logical reason for this might be for familiarity for troops so they can easily transition to the new rifle. I will say though that the higher power and recoil of the .280 british in comparison to say, a 5.56mm is less of an issue, largely due to things like muzzle breaks and softer recoil systems. The FN SCAR for example shoots pretty softly, as does the Tavor 7 and many other modern battle rifles, and so presumably a .280 british which is lighter and has less energy than a rifle round, it should be less.

The big thing I would say is that while 7mm rounds have good ballistic coefficients, they only achieve this with far heavier rounds than 6mm and 6.5mm rounds. A 140 grain 6.5mm can easily attain .6 BC, while a 150 grain 6.5mm round will attain .71, and a 7mm at around 140 grains is only at best maybe .5 BC, but all the figures I can find are around .4 BC. This using the G1 figures. I have figures for Hornady, but for some reason the sierra match king website is down? O.o It depends on the manufacturer but generally a 6.5mm or 6mm will be more aerodynamic and accurate for it's given weight, which is more useful with intermediate cartridges. With less power you can get a higher velocity, which is nice. I made a chart detailing a lot of this information some time ago, but it doesn't include the 6mm or .280 british, but I still figure it might be useful for a baseline comparison.

My train of thought was a 1950s introduction and gradual upgrades over time. So, probably will be the British .280 I'll use and refine over time...particularly since I also wish to use a semi-auto only FN FAL (basically British L1A1 SLR) as DMR/reserve rifle.

Ironically, going with the rotating bolt (as opposed to the EM-2 design of a flapper lock) but keeping the long stroke pistol almost makes it a British bullpup cousin of the AK-47.

[The Akasha Colony]

My train of thought was a 1950s introduction and gradual upgrades over time. So, probably will be the British .280 I'll use and refine over time...particularly since I also wish to use a semi-auto only FN FAL (basically British L1A1 SLR) as DMR/reserve rifle.

Ironically, going with the rotating bolt (as opposed to the EM-2 design of a flapper lock) but keeping the long stroke pistol almost makes it a British bullpup cousin of the AK-47.

The problem is that the concept behind .280 British became obsolete in the 1960s-1970s. Of course, we only know it with the benefit of hindsight but SCHV became all the rage in the 1960s-1970s as 5.56 and 5.45 came into service. Older rifles with heavier, slower bullets like 7.62x39 hardly disappeared given the sheer number of such weapons already produced, but the major powers switched over to SCHV cartridges. And .280 British is definitely not high-velocity.

[Morrdh]

My train of thought was a 1950s introduction and gradual upgrades over time. So, probably will be the British .280 I'll use and refine over time...particularly since I also wish to use a semi-auto only FN FAL (basically British L1A1 SLR) as DMR/reserve rifle.

Ironically, going with the rotating bolt (as opposed to the EM-2 design of a flapper lock) but keeping the long stroke pistol almost makes it a British bullpup cousin of the AK-47.

The problem is that the concept behind .280 British became obsolete in the 1960s-1970s. Of course, we only know it with the benefit of hindsight but SCHV became all the rage in the 1960s-1970s as 5.56 and 5.45 came into service. Older rifles with heavier, slower bullets like 7.62x39 hardly disappeared given the sheer number of such weapons already produced, but the major powers switched over to SCHV cartridges. And .280 British is definitely not high-velocity.

There was apparently a 'High Velocity' version of the round produced.

Though what ballmark are you using for high velocity?

[Danternoust]

Noticed that the 5.56mm, 5.8mm, and the 5.45mm rounds have roughly the same overall length and case capacity.

I think high chamber pressure and carbine length barrels are disadvantageous for the person firing the round, but 90% of a bullet's weight is in the lead, so one could achieve a GPC much easier with a 5.56mm with the bullet seated less deep, a long steel core bullet, and base bleed.



Anyway:
70s US army research on the 5.56mm
https://www.thefirearmblog.com/blog/201 ... x38-fabrl/
http://looserounds.com/556timeline/556dw-1975/

ammunition consumption for small arms
https://www.belfasttelegraph.co.uk/news ... 80666.html
https://apps.dtic.mil/dtic/tr/fulltext/u2/a451782.pdf

[The Akasha Colony]

There was apparently a 'High Velocity' version of the round produced.

Though what ballmark are you using for high velocity?

The actual SCHV cartridges developed and brought into service trend to 880 m/s and above from full-length barrels. 5.56 is generally above 900 m/s.

And there's more to it than just making the existing larger-caliber .280 bullet faster. Making .280 faster with the same bullet mass results in greater recoil (of course), while reducing density or volume will reduce ballistic performance compared to a smaller-caliber bullet optimized for the same mass/energy.

[Manokan Republic]

It's a really cool idea, and I think the EM-2 would have been a big leap forward in military technology if it was ever adopted. A more accurate aerodynamic bullet is a great idea for a lot of reasons, and as range and weight is very important for a machine gun, a lighter weight round that could maintain the same range as the 7.62mm NATO, and more or less same power at longer ranges, would have been fantastic. Today, a 6.5mm Grendel more or less can fulfill the role of a .280 or .270 British, and is more aerodynamic and accurate as well as easily adapted to fire in 5.56mm rifles, while something like the 6mm aluminum (or a modernized version of it) more closely achieves the ideal of long range, lightweight, moderate power round. From a practical standpoint it would be easy to convert the SA80 to firing 6.5mm grendel rounds, while from an ideal standpoint the 6mm aluminum would be the lightest weight, albeit a little bit weaker (although a modernized version in theory could be more powerful). The aluminum cased guns tended to either need insulation in them or catch on fire too easily, an issue easily resolved with a coating on the aluminum (such as thin polymer) or a change in the bolt/barrel material so galling of the aluminum is reduced. They were also a little bit weaker.

The .280 british series of rounds to my knowledge were rather low velocity given the larger 9.1 gram bullet, less aerodynamic (with a B.C. of about .4), and 21.5 grams, which is only marginally lighter than a 7.62mm NATO at 25.5 grams, or 20% lighter, with 2800 joules. A 6.5mm grendel has a BC of .5 with an 8 gram bullet, a higher velocity, and is 16.3 grams, about the same as an Ak-47, and substantially lighter than the 7.62mm, allowing for about 70% more ammunition to be carried, or 20-30% less than a 5.56mm, with 2600 joules. The 6mm aluminum in theory is as light or lighter than a 5.56mm, with a minimum of about 10.5 grams, allowing evne more rounds to be carried, with potentially a BC of .5 or .6 depending on what bullet you use, but it was notably weaker than both, at only 2000 joules vs. 2600 and 2800. With modern gunpowder, it is possible to achieve more power in the same case, with the .25-45 sharp for example using a 5.56mm case but achieving 2350 joules vs. 1800 joules or 30% more power, so it is conceivable you could improve it's capabilities quite a bit. The .280 british is by no means bad, it is a heavier, higher recoil, and slightly shorter range option than the other two or in comparison to other low-drag intermediate bullet designs.

That being said! All of the proposed changes you've presented make sense, and if you want the .280 british specifically, something akin to a bullpup FAL design keeps in line with the british weapon designs while also still remaining similarity to the EM-2. A rotating bolt does make sense for small arms, in large part due to it's simplicity (with the original EM-1's being hideously complex to manufacture for example), and you could use a modernized HK416, ak-47 style etc. internal design instead. You could just say that it is a gun with a different firing mechanism in it, but looks like an EM-2. A logical reason for this might be for familiarity for troops so they can easily transition to the new rifle. I will say though that the higher power and recoil of the .280 british in comparison to say, a 5.56mm is less of an issue, largely due to things like muzzle breaks and softer recoil systems. The FN SCAR for example shoots pretty softly, as does the Tavor 7 and many other modern battle rifles, and so presumably a .280 british which is lighter and has less energy than a rifle round, it should be less.

The big thing I would say is that while 7mm rounds have good ballistic coefficients, they only achieve this with far heavier rounds than 6mm and 6.5mm rounds. A 140 grain 6.5mm can easily attain .6 BC, while a 150 grain 6.5mm round will attain .71, and a 7mm at around 140 grains is only at best maybe .5 BC, but all the figures I can find are around .4 BC. This using the G1 figures. I have figures for Hornady, but for some reason the sierra match king website is down? O.o It depends on the manufacturer but generally a 6.5mm or 6mm will be more aerodynamic and accurate for it's given weight, which is more useful with intermediate cartridges. With less power you can get a higher velocity, which is nice. I made a chart detailing a lot of this information some time ago, but it doesn't include the 6mm or .280 british, but I still figure it might be useful for a baseline comparison.

My train of thought was a 1950s introduction and gradual upgrades over time. So, probably will be the British .280 I'll use and refine over time...particularly since I also wish to use a semi-auto only FN FAL (basically British L1A1 SLR) as DMR/reserve rifle.

Ironically, going with the rotating bolt (as opposed to the EM-2 design of a flapper lock) but keeping the long stroke pistol almost makes it a British bullpup cousin of the AK-47.

Hmmm... well, it's not a terrible option, it's just a little heavier than you might like, and a little less aerodynamic. If an emphasis of power was made on the round, it could become bigger, and thus be capable of using larger more aerodynamic projectiles. There's also very strangely constructed projectiles that might increase the BC.

HOWEVER! I think I've got an idea. First, I did find a 150 grain 7mm round with a really high BC, at .574 which is actually quite high, so you there is room for improvement over the original round. The price of the bullet is quite high, but this can be overcome given that, bullets are pretty cheap anyways relative to the whole military, and mass produced versions, like the 75 grain tula ammunition variants of the 77 grain blackhills ammunition, is usually about as aerodynamic, but just less accurate. Second, the .280 british went through a number of revisions, from aluminum cased rounds to higher pressure rounds. My idea would be to switch to an aluminum case, so that way it's much lighter weight, and a guess based on the bullet weight and overall cartridge weight (9.1 grams for the bullet, 20.3 grams for the cartridge, and no clear mention of how much powder it uses) would be that it would be 14-15 grams instead of 20.3 grams, which is quite a good achievement. Third, you could have two variants of the cartridge, a higher velocity one intended for use in machine guns and designated marksmen weapons, and a lower velocity one for use in the normal every day rifles. By using more powerful gunpowder, you could get the cartridge going all the way up to 850 m/s or more, but it would have a lot more recoil. So instead, you have the lower velocity round designed for use in regulr rifles, and the higher velocity rounds designed for use in heavier machine guns.

In this way, you could have say, a 2600-2800 joule variant for your rifle, and a 3500-4000 joule variant for your heavier weapons like machine guns, and in theory both guns could fire both rounds. So instead of having two different bullets like a 5.56mm and 7.62mm NATO, you have two identically sized .280 bullets that could feed in to the same guns, but one is more powerful and is intended for use in heavier weapons, and in a pinch could be used in your lighter rifles, or on purpose in something like a designated marksmen rifle. This would in theory reduce the complexity of sharing features between the weapons, and also makes it so you can share ammunition when you need to, with heavier machine guns potentially using the weaker ammunition when in an infantry squad, and more powerful ammunition if mounted on a tripod or something. You incorporate the history of the round in to your design, and also get a fairly light and powerful full sized rifle round, as well as a decent intermediate cartridge. The velocity would be low, but it still would be about the same as an Ak-47, 7.62mm NATO sniper round, or 8mm mauser, so it wouldn't be fantastically slow. You would have good barrier penetration, and in testing the 7mm rounds showed better timber and wood penetration than the .30-06 at the time, so it seems ot hold true. Higher velocity rounds have a tendency to disintegrate or be deflected by common barriers, like sand, glass, thin sheet metal, and something like an Ak-47 penetrates through stuff like concrete extremely well, while a 5.56mm really does no, being stopped by glass, small amounts of sand and other things like this. The 7mm round would penetrate armor slightly worse, but given it's size and power, it would be at least as good as the 5.56mm.

By my comparisons, this more or less would be a rough figure of the round's capabilities. The .280 British actually does really well, remaining super-sonic until 1200 yards with 423 ft/lb (571 joules) of energy, while maintaining energy equal to the 5.56mm at 350-400 yards (1800 joules), and at 600 yards having 935 ft pounds (1260 joules), which is more or less equal to an M4 carbine. For the higher velocity .280 british, it has as much energy as the 5.56mm at 600 yards, remains super sonic until 1400 yards with 423 ft/lb (571 joules), doing quite well at 300 yards as well. The 5.56mm is only supersonic at 550 yard with 311 ft/lb (420 joules), and 665 foot pounds (900 joules) at 300 yards, while the 7.62mm nato is super sonic at 850 yards at 426 foot pounds (575 joules), and has 5.56mm energy at 350 yards. Basically, the regular, non-high velocity .280 british is as powerful as the 5.56mm at 350-400 yards, and is super sonic until 1200 yards, longer than the 850 yard range of the 7.62mm NATO. You get about the same range with the high velocity .280 british, but way higher power levels than the 7.62mm NATO at long ranges, with the low velocity .280 british surpassing the 7.62mm NATO a 400 yards Despite the higher energy levels, the better aerodynamics of the 7mm would in this case mean it is actually more powerful than the 7.62mm at long ranges, and would penetrate slightly better through most barriers. Sufficient power at close ranges, and greater power at long ranges. Ultimately, the bullet drop is less than the 5.56mm or 7.62mm NATO at ranges where it matters, due to it's better aerodynamics meaning it slows down less, even with a lower initial muzzle velocity.

So! It possesses a significant advantage, a long range allowing it to compete with heavier rounds, and pretty decent power, giving it theoretically good barrier penetration (slightly heavier and faster than the Ak, with a skinnier bullet, should equate to better penetration). Your only issue would be recoil, given it's fairly close to .308 levels, and this could be compensated for in part with a muzzle break, smoother action and dual spring guide rods, along with other recoil reducing measures. A simple but not as commonly used method to reduce recoil is a simple shoulder pad, and if made out of bullet proof material like body armor, would serve multiple purposes and absorb energy well, thus reducing much of the impact of felt recoil. As long a muzzle rise is eliminated, a shoulder pad can help eliminate any pain you might feel from shooting, so if the recoil could conceivably be uncomfortable in rapid fire, this problem is more or less eliminated. From what I've seen the EM-2 was not uncomfortable to shoot in semi auto, but was hard to control in full auto. Recoil reducing measures combined with a forward grip could help eliminate some of that, as well as a shoulder pad so you could squeeze it in your shoulder real tight without hurting yourself.

[Kazarogkai]

A rather conventional maxim gun chambered in a .50 cal bullet, minus the addition of a somewhat conventional pistol grip and trigger similar to the M1917 BMG. Could it work out ok? More specifically I know that such a thing is theoretically possible since Ive actually heard of examples with even bigger bullets but I want to know if I one could keep it under 150 pounds counting the water, ammo, and tripod and two would it still be able to reasonably serve as the principle Battalion level HMG for an infantry battalion in the interwar-WW2 era. Just thinking it would be a somewhat decent infantry support weapon along with acting as a sort of low level AA weapon, atleast in theory.

The reason for asking honestly is because at the time the Kaza made use of a .25 cal bullet which while performing it's role admirably they considered in their HMGs as a little under powered relative to their rivals after experience fighting in WW1 against the British and their allies. Hence what was originally only meant to function as and was inspired by the Germans 13mm MG08 in an AT/AA role ending up replacing their older .25 cal MMG as their main MG. At least that's the story I'm going with for the most part.

Thoughts?