Deleted member 1487
Sure, but I was talking about modernizing the Savage cartridge the way the US did with turning the .30-06 into the 7.62 NATO.
WI: M1 Garand designed around .250-3000 cartridge
- Thread starter tomo pauk
- Start date
Possibly. In the post-war NATO standardization I could see an attempted modernization of the .25 US Rifle to something resembling a .25 Ackley Improved style round as the 6.35mm NATO. Straighter case with a sharper shoulder. The problem would be the US would likely balk at the idea as it could create confusion and non-compatibility with NATO stock vs. US Stock, likely killing the idea and leaving us with the standard .250 Savage militarized .25 US Rifle, although with an improved load and bullet likely.
I think if the US was already successfully using the .25 through WWII this would be less of a factor. The idea would be that Company-level heavy weapons Platoons would handle fire support and anti-armor using the M1919 and its derivatives or replacement(s) with the Squad-level fire-support focuses on anti-personal. Which brings us too...
There was an experimental belt-fed Johnson, irrc, and I would l think it could be a contender; but in the end a more "modern" design in the form of the M60 to me seem the more likely winner in any competition. And, yes, I see it as more of a SAW in use (as stated in the previous paragraph) but I think it would still be, mechanically, the M60 as we know it.
If they go with a .30-06 medium machine gun as a standard, then I would agree that it would likely be adopted as the 7.62 x 63mm NATO / 7.62 NATO and the 7.62 x 51mm NATO would end up being a 7.62 x 48mm / .30-250 wildcat derived from the 6.35 NATO / .25 US (slightly shorter case length do to necking it up).
marathag
Banned
There wouldn't need a lot of modernizing, other than it too would have the same hat, but with new nametag of 6.35 NATO.
I don't think .30 carbine would have got a start in this timeline.
250 Savage has a recoil energy of 7.8 ft-lbs with a 7.5 pound rifle, while 30 Carbine is 3.5 ft-lbs from a 7 pound rifle.
For comparison, the .223 is 3.9 ft-lbs from a 7 pound rifle, and 30-06 was 17.6 ft-lbs from an 8 pound rifle.
On the other side of the Iron Curtain, the 7.62x39 was 6.9 ft-lbs with a 7 pound rifle.
No real need for another light cartridge for a carbine for rear area troops.
Deleted member 1487
Lo' and behold Gun Jesus with the answer:
https://www.forgottenweapons.com/belt-fed-johnson-lmgs/
The Johnson ran on the MG42 short recoil principle, so perhaps it might be assuming the Johnson is even adopted by the US army in the first place, as it would be cheaper to convert existing models rather than adopt an entirely new gun. The M60 instead of the M1919 though for the MMG just makes more sense.
It would be interesting if they actually went the Swedish round and mated the German 8mm to their existing case:
https://en.wikipedia.org/wiki/8×63mm_patron_m/32
Lots of reparation 7.92mm production equipment available post-war. The 48mm case with a 7.62 bullet would be too weak a combo.
A 7.92/8mmx63 M60 would be quite the nasty weapon and effectively an earlier, though weaker version of the .338 LWMMG.
Oh...well given how the .30 Carbine did on full auto the 6.35x48mm is probably too powerful for controllable full auto. Though yes the .30 Carbine would be redundant with a carbine 6.35mm proposed earlier.
marathag
Banned
7.62 NATO thru an M14 was still 15 ft-lbs, so half the recoil of that. Still be a handful, but 6.35NATO would be just a bit worse than an AK-47. Call it 'mostly controllable', and 'controllable' if its a rifle with a straight line stock and a muzzle brake.
Well, yes, the M1919 will need to be replaced eventually. But without the 7.62 x 51mm NATO our options are either the 6.35, .30-06, or--possibly--your proposed 7.92 x 63mm (although I think it more likely they'd just stick with .30-06 at that point). As I believe they would field two separate MGs (a SAW and a company or platoon level fire-support MG) instead of a universal (as OTL M60), I think the design and development of the M60 would lead to the SAW and we'd see something else eventually replacing the M1919--maybe even still Browning derived?
Well, yes and no...the .308 Winchester / 7.62 NATO is actually descended from the .250-3000 Savage, via the .300 Savage. The 7.62 x 48mm was what I figured would be a starting Wildcat made by necking up the 6.35 x 48mm (actual case length I have seen as 48.46 and 48.6, in the latter case it would be called 49mm I think), there is no reason to believe the wildcaters and, later, Winchester themselves wouldn't come to the same conclusion as OTL and lengthen the case to create the .308 Winchester we know and love IOTL. Even if that isn't the case, the 7.62 x 48mm should still provide plenty of capacity to handle most of the sub-150gr .30 caliber bullets adequately for the majority of uses--in fact it would pretty much be the .300 Savage for all intents and purposes (47.5mm case length) which was only 70 ft/s shy of the original .30-06 using 1920s powders and bullets.
EDIT: Per Chuck Hawks, "The Hornady Superformance load makes [the .300 Savage] the approximate equal of the .308 Win. (150 grain SST at 2740 fps)"
Deleted member 1487
Perhaps, if it works and isn't too heavy, why not?
The issue is why use a cartridge that limits you to 150 flat base or slightly boat tailed bullets? For MMGs and sniper rounds you need the 178 grain long bullets. With better powders the 63mm case even with a 7.62mm bullet could achieve some pretty serious power.
Using equivalent powders the .300 Savage can push a 168gr to within 100-200 fps of the .308 Win. firing the same 168gr bullet and it is capable of handling up to 180gr (only up to about 2200 fps though), so I think it is possible to accept the idea that if IOTL the 7.62 x 51mm was accepted in the role there is no reason to believe that the nearly identical 7.62 x 48mm or improved version as 7.62 x 51mm also couldn't be accepted ITTL.
But, yes, I agree that if the infantry rifle and SAW are using the 6.35mm and you are going to use a .30 cal. round for MMG and Sniping it makes more sense to just stick with the .30-06. My initial response was more in direct response to the general idea that such a round "would be too weak a combo" rather than to say it would be better or more suitable than the .30-06, 8mm Mauser, or the mentioned 7.92x63mm for military use.
Deleted member 1487
I'd check the powder loads possible and the pressures that would build up with a longer, heavier bullet pushing deeper into the case.
Doesn't say anything about the pressures, but Nosler has some basic reloading data available for the .300 and using 36gr uncompressed IMR 4064 power they show a 180gr Spitzer with a MV of 2263 fps (using compressed 38gr they show a max MV of 2368 with that powder). Compare that to the .308 using 39gr of IMR 4064 with the same 180gr Spitzer for MV of 2297 fps. Of course, with the .308 it can be built up to 43gr of IMR 4064 for a MV of 2603 fps. Looking at all the powder options for both and excluding compressed powders and max-pressure or over-loads (for the sake of barrel life and reliability in a military rifle) and only looking at IMR (Improved Military Rifle--so excluding more modern or exotic bench powders) powders only it looks like the best balance for each with the 180gr class of bullets are:
.300 Savage: 36gr (100% Load Density) IMR 4064 @ 2263 fps
.308 Winchester: 41.5gr (94% Load Density) IMR 4895 @ 2559 fps.
.30-06: 56.5gr (94% Load Density) IMR 4350 @ 2734 fps. (thrown in for good measure)
If you could raise the pressure limit and use better powder I think you could get the .300 within a few fps of the .308. Neither will ever compete with the .30-06 at these weights, though, simply because of the lack of capacity. Also, I don't think the .300 would ever really be in competition with the .308, instead one would just replace the other as IOTL--so the real issue comes down the old argument--.308 or '06?
Deleted member 1487
Without the need for a modern rifle/LMG round that cuts weight there is no reason to drop the .30-06.
Yup, like a said a few posts up...
So, after all of this running around, we've circled right-back to where we started: 6.35 x 48mm NATO for Rifle/SAW and 7.62 x 63mm NATO (or one of the similar .30-.32 caliber early 20th Century rifle rounds) for MMG. The only point I really might disagree with you is that the snipers would need the 7.62. They may continue to do so through the 1960's but eventually I think most marksmen would adopt the 6.35 with VLR rounds for their flat trajectories and high BCs. The very long range snipers would likely still develop .50 cal rifles as OTL for the "big ones."
I guess this leaves us with the next question: if TTL M14 equivalent is using the mid-power .250 and is therefore theoretically more successful, would Stoner's AR-10 platform ever be adopted or would it be completely passed over--with the 6.35mm M14 replacement not occurring until sometime in the 1970's or 1980's? If this is the case, what would its likely replacement be or be similar to?
marathag
Banned
I don't see different Cartridge changing the politics at Springfield Armory. AR-10 would still be looked over from not being invented in house, and it's likely that Lemay would still be looking for a high tech sentry gun for airbase protection, that might be in 250 Savage, but the rest AR-15 as OTL
Between the improved .250, improved .30-60 and .50, there is enough on a plate for the NATO snipers. Plus, both .250 and .30-60 will see new light and medium machine guns designed for them.
Post-war, there would be plenty of Soviet, German, British, French, Belgian and German guns designed around intermediate rounds - inspirations abound for any gunsmith. Not that US didn't have good/great designers of infantry weapons in the 1st place.
To be clear, I was including the AR-15 under the umbrella of the AR-10 platform (the charging handle was moved a few other minor modifications, but those are changes that still could happen within the AR-10 even without a caliber change). My thinking was that even if Lemay somehow gets the AR-10/15 for the AF, would the Army and/or Marines bother considering it if they already have a select-fire rifle that works sufficiently well in the ATL M14? This may relegate the AR platform to a historical curiosity or at the very least delay its adoption until after Vietnam.
Deleted member 1487
Depends on the distances they'd be shooting at. At 1000m a VLD 6.35 would probably be good enough. But VLDs only came about in the 1980s:
https://en.wikipedia.org/wiki/Very-low-drag_bullet
For longer ranges you'd want at least a 7.62 VLD if not even 7.92 (or as they do now use 8.5mm magnums after stepping down from the 12.7mm). The really heavy 7.62s even get up to 230 grains, which you'd want the extra powder capacity of the 63mm case for. Though we might well see the distinction between the DMR and sniper role between the two calibers.
As marathag says the politics of US army procurement would likely pass over the AR-10 anyway, though it might get more play due to the lower pressure round being less likely to result in the barrel burst that killed it's chances for good IOTL.
marathag
Banned
Unit Cost would be the big selling point(OTL all producers for M14 were over $110 each), along with lighter weight over the ATL Garand based *M14
Deleted member 1487
Assuming the M14 is as bad as the OTL version, would the AR-10 in 6.35mm or 5.56mm be given a chance? The AR-10 even though it was ready and sold to other countries wasn't adopted even though the AR-15 had it's own set of issues as of the 1960s. I wonder if it would perform better in Vietnam due to the heavier bullet being able to penetrate jungle cover better and there being a much lighter SAW option than the OTL M60.
The 7.92x41mm CTME low weight, low Drag intermediate round was developed by the Spanish (mainly by German engineers) starting in the Late 1940's To say that VLD bullets were not developed until the 19880's is a rather sweeping generalization. I have always been of the opinion that the British EM2/Rifle No9 using this .96X41 round or a derivation of it would have been a superb weapon in it's day. Get the USA to accept this round and the M14 rife might have actually made it into meaningful service!
marathag
Banned
A better cartridge wouldn't have helped with the Q/C and production issues that the rifles suffered from