Discussion in 'Alternate History Discussion: After 1900' started by HistoryGunsFreedom1776, Mar 15, 2019.
No AR15 in 6.8 SPC in the mid 50s.
I mentioned .270 British which is a different cartridge to the .280 British. The .270 round had 2200 joules of energy and was similar in power to the 7.62x39 Soviet round with 2100 joules energy. I think it would qualify as an assault rifle round.
No, but there was a .270 Winchester (more powerful round) and .280 Remington.
It was intended as such.
For what? The .30-06 was the most powerful of the military cartridges and it did fine in a semi-auto rifle. The Swedes and Norwegians were fine with a 6.5mm cartridge for their MG use other than for HMGs, but then for those at least an 8.5-9mm magnum cartridge is needed.
Very good arguments have been made for a 6mm universal round to cover all infantry needs other than the HMG or very long range/anti-material sniper platform.
With something like the .270 British or 6.8mm SPC you have a round that is better at energy retention and penetration than a SCHV round, but anything between 6-7mm can be serviceable in that role. Its just a question of trade offs and what is deemed desirable by doctrine.
Right now the US army is developing a next generation weapon in 6.8mm:
They are longer, heavier and more powerful than .30-06
Well, I’ll be honest that I’ve considered reviving this cartridge in the timeline I’m working on (still working on it):
In order to have more bang for the buck, there’ll be two separate versions of this timeline with the other one sticking with 7. 62 NATO
AR-10 instead of the M-14 might actually be more interesting than it seems... The implications of sticking with 7.62 longer probably aren't huge, and I suspect NATO will downsize at some point (5.56 is a long way from a forgone conlusion without a US push though) but all things being equal I really wonder if we don't end up with NATO adopting essentially the M-4 (as in a mid size cartridge AR-15 carbine) when intermediete cartridges become a thing.
OTOH if the AR-10 gets the M-16s reputation early on I wonder if the US might adopt some European rifle, perhaps a bullpup, coming out of Vietnam... I'm almost picturing the SA-80 as a joint program. Or somehow landing on the AUG...
The parent case is the .30-03, so yeah.
Actually it is less powerful than the .30-06 with a 140 or less grain bullet. Not by that much, but enough to reduce recoil significantly, especially with a lighter bullet.
It kind of did in testing due to the burst composite prototype barrel. If anything the US would just fall back on the M14. Probably would just go with the FAL if they went with anything European, the US military has never liked bullpups.
Ok, if we play along with the premise, how early would the M14 have to be ready (assuming the quality control issues are resolved quickly) for other NATO countries to adopt it? The FAL was in service starting in 1953, so would it need to be ready at least around the same time with no QC issues? Or would it require a license agreement like FN was offering with the FAL?
And not new, either. When Garand was working on the followup to the M1 during the war, each prototype had a larger brake than the previous.
And that all got tossed for the grenade launcher for the M14, that was hardly ever used.
270 Win is 30-30 based, but loaded to far higher pressure.
The cartridge that should have been used was 250 Savage or 257 Roberts
The 6mm Remington looks good too, also uses same case as the .257 Roberts.
Apparently they had a grenade launcher that fit over the muzzle brake, so I don't get what happened there.
This part though is highly interesting:
A proto-M14 might have been the way to go in TTL; keep the .30-06 and adopt one of the developed mid-1940s Garands.
for the context of an individual combat rifle, useful out to 600m, there really isn't a significant difference between the 3
they are all descent from the same parent cartridge, have the same oal, and as far as ballistics go, you're splitting hairs
A .270 bullet out of the same case will be quite bit flatter firing and high energy at 600m than the .30 caliber, especially if there is a long, nearly same weight bullet used (excellent sectional density). The 140 grain .270 is a lot more aerodynamic than a 150 grain M2 Ball .30 cal round.
Its certainly an option for what I'm working on currently but my lips are sealed until the reveal
.270 Win is actually based on the .30-03 cartridge that M1903 Springfield rifles originally used, which is why it's sometimes possible to stuff a .270-06 in a .270 Winchester chamber. The .30-03 cartridge fired a 220 gr roundnose at about 2,300 fps, so the pressure difference compared to .270 Winchester is actually fairly small.
4 inches difference at 400 yards, using a 200 yard zero,
3 inches difference at 300 yards, using a 100 yard zero,
in the context of a hunting rifle that can be significant, not so much in the context of a military rifle, simply due to how many other factors you need to account for like the fact that you're buying several thousand/million firearms
and the round is still overkill for a man at 600m
Not insignificant if you're planning on having a universal caliber.
Better than underkill. Especially if you're planning on having a universal caliber, as NATO was up until the 1960s, which means use in sniper rifles and MGs, so 1000m is also a consideration if not even further in the case of MMGs (the Brits planned on at least 2km range for their .280 cartridge in the MMG role).
Though they were also planning on a lighter, more compact cartridge, so they would shorten it quite a bit if they were going to use it.
Thanks for the links, only really confirms my opinion they should have done things very differently, such as waited for the AR-10 and shifted caliber down to 6.5mm at a minimum.
Separate names with a comma.