British Army adopts M1 Carbine as primary rifle for Normandy

  • Thread starter Deleted member 1487
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And 7mm Mauser is still flatter shooting than 30-03 or the later 30-06, so missed the boat there.

Summary: the US discovered after WWI combat that the Spitzer bullet it thought it used in the Springfield rifle and in its machine guns did not have the 4,200 meter flyout range the Army Ordnance people who "tested" it claimed. Flyout was about 3,000 meters. The British, French and the Germans, who had ~4,000 meter flyouts had tested their bullets to use "beaten zone" machine gun tactics or indirect harassment bullet hose fires to get behind the trenches and cause casualties behind the presumed safety of the front lines. (Trust me, it is cheaper than mortar shells and it is effective to keep people miserable and or under some cover, hence communication trenches reaching at least a 1-2 km back.).

I covered that issue.

After getting their act together, the Americans improved the Ogive on their bullet (i.e. copied the Mauser bullet as well as the rifle.) and improved the aerodynamics to achieve a comparable performance of 4,000 meters or more.

And the postwar correction. (~1926.)

7mm wasn't as good at killing horses at 1000+yards, so got the .30 caliber instead.

BTW, the Spanish snipers, during the Spanish American War, were not interested in the horse; just the man who rode it.
 
I think the .30 Browning still used "machine gun ammunition" but the 30-06 rifle rounds that passed through it would not hang it up.
no, the army used m2 ball (roughly the same performance as the 1906 ball) for both,
they made the switch back from m1 ball because in a classic case of gone horribly right they found that the max range of m1 ball was longer then the safety zone on their practice ranges
plus the soldiers complained about excessive recoil in the springfield rifles

The tradeoffs you have to make for a universal bullet are incredibly complex.
ok, so you want 1 projectile shape?
 

Deleted member 1487

I want a Spitzer (7.5x55mm Swiss is a good hypothetical candidate).

Muzzle velocity...………………………... Maximum range
760 m/s (2,493 ft/s)…………………………….. 5,000 m (5,468 yd)
780 m/s (2,559 ft/s)…………………………….. 5,500 m (6,015 yd)
810 m/s (2,657 ft/s)…………………………….. 5,800 m (6,343 yd)
Small problem there with the small size of the carbine case and the long boat tail of the heavy M1 projectile. In fact the Garand couldn't even use it without breaking.
 

Deleted member 1487

The Swiss solved it.
They continued using a bolt action rifle until they adopted a much heavier automatic rifle:
https://en.wikipedia.org/wiki/SIG_SG_510

On top of that the 7.5mm cartridge was significantly less powerful than the .30-06. Trying to use a 178 grain bullet in a .30 carbine cartridge is going to result in a bullet that falls off at 100m. It's basically at best going to be a shittier .300 Whisper.
 
Small problem there with the small size of the carbine case and the long boat tail of the heavy M1 projectile. In fact the Garand couldn't even use it without breaking.
30 Carbine
Overall Cartridge Length (IN) - 1.7
Case Length (IN) - 1.28
Full Case Capacity (GR WATER) - 20
Bullet Length (IN) - .72
Bullet Seating Depth (IN) - .3
Displaced Water (GR) - 5.641
Effective Water Capacity Of Case (GR) - 14.359

Any deeper seating, and you are looking at compressed powder loads. That's not good. So you are looking at pistol powders, need to find one that likes no void space in the case.
Easier is to toss the OAL limit, and go longer, but the limited seating area rules out most boat-tail designs

It doesn't kill you to have multiple bullet designs, especially since why would you bother to boattail a tracer? need all the space you can get to keep weight somewhat close to your ball and ap loads
 
Trying to use a 178 grain bullet in a .30 carbine cartridge is going to result in a bullet that falls off at 100m. It's basically at best going to be a shittier .300 Whisper.
300 Blackout,asa Whisper, has 24 grains water capacity vs 20 of the carbine.

Some describe the 300 BLK as a way to get 45ACP energy delivered accurately at 150 yards.
 

Deleted member 1487

300 Blackout,asa Whisper, has 24 grains water capacity vs 20 of the carbine.

Some describe the 300 BLK as a way to get 45ACP energy delivered accurately at 150 yards.
Perhaps. Thing is the muzzle velocity is going to be very low due to how much space the bullet will take up in the base, while the weight of the bullet will increase the recoil in such a light platform even with the low muzzle velocity...150 yards accuracy is probably optimistic with that case and bullet.

30 Carbine
Overall Cartridge Length (IN) - 1.7
Case Length (IN) - 1.28
Full Case Capacity (GR WATER) - 20
Bullet Length (IN) - .72
Bullet Seating Depth (IN) - .3
Displaced Water (GR) - 5.641
Effective Water Capacity Of Case (GR) - 14.359

Any deeper seating, and you are looking at compressed powder loads. That's not good. So you are looking at pistol powders, need to find one that likes no void space in the case.
Easier is to toss the OAL limit, and go longer, but the limited seating area rules out most boat-tail designs

It doesn't kill you to have multiple bullet designs, especially since why would you bother to boattail a tracer? need all the space you can get to keep weight somewhat close to your ball and ap loads
They did have the 150 grain bullet high pressure test load, but a test cartridge to proof the barrel is quite different from a mass use service round. I'd imaging using the ball powder isn't an issue for the .30 Carbine cartridge with the M1 bullet, but that would mean a seriously reduced powder load to maintain the relative pressure. Of course at that point there really isn't a benefit to the 18 inch barrel and anything over say 10-12 inches could be a detriment due to the fall in pressure at a certain point once the powder is burned up and the needless friction resulting from bullet-barrel contact. That's why subsonic bullet platforms have short barrels.

If you're going to toss the OAL, might as well make it bottlenecked cartridge like the German 8mm Kurz. Just use the .30-06 case and chop it down to say 36-39mm to keep the case taper within reasonable limits. Of course then you've gone beyond what the Carbine platform could handle at that weight and you're back to having a system in the 3.5 kg range, as you've basically created an equivalent to the 7.62x39 cartridge, but more powerful and difficult to control in automatic due to the weight of the bullet unless you install a good muzzle brake (not FG42 good, but better than the M14 one). One the plus size you could basically use a scaled down Garand gas system to make the design task easier...

Or you could just use the rimless .351 WSL case and the M2 Ball bullet with a mild steel core to get it down to 125 grains and scale up the M1/2 Carbine to 6-7 lbs to deal with the heavier cartridge.

Regardless the M1 Ball bullet and .30 Carbine case aren't going to work well beyond creating a subsonic round for close range ambushes/sniping.
 
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Perhaps. Thing is the muzzle velocity is going to be very low due to how much space the bullet will take up in the base, while the weight of the bullet will increase the recoil in such a light platform even with the low muzzle velocity...150 yards accuracy is probably optimistic with that case and bullet.
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They did have the 150 grain bullet high pressure test load, but a test cartridge to proof the barrel is quite different from a mass use service round. I'd imaging using the ball powder isn't an issue for the .30 Carbine cartridge with the M1 bullet, but that would mean a seriously reduced powder load to maintain the relative pressure. Of course at that point there really isn't a benefit to the 18 inch barrel and anything over say 10-12 inches could be a detriment due to the fall in pressure at a certain point once the powder is burned up and the needless friction resulting from bullet-barrel contact. That's why subsonic bullet platforms have short barrels.

If you're going to toss the OAL, might as well make it bottlenecked cartridge like the German 8mm Kurz. Just use the .30-06 case and chop it down to say 36-39mm to keep the case taper within reasonable limits. Of course then you've gone beyond what the Carbine platform could handle at that weight and you're back to having a system in the 3.5 kg range, as you've basically created an equivalent to the 7.62x39 cartridge, but more powerful and difficult to control in automatic due to the weight of the bullet unless you install a good muzzle brake (not FG42 good, but better than the M14 one). One the plus size you could basically use a scaled down Garand gas system to make the design task easier...

Or you could just use the rimless .351 WSL case and the M2 Ball bullet with a mild steel core to get it down to 125 grains and scale up the M1/2 Carbine to 6-7 lbs to deal with the heavier cartridge.

Regardless the M1 Ball bullet and .30 Carbine case aren't going to work well beyond creating a subsonic round for close range ambushes/sniping.

Congratulations; your carbine has to have a barrel length of 15 inches at least as they measured in those days. Guess you better start thinking about BULLPUPS for your paratroopers.

In case you wondered, did he think about that bullet, or was he spit-balling notions?
 

Deleted member 1487

But that was not the gedankenexperiment, was it? (thought exercise.)
The result of the exercise is that the result isn't worth the trouble, especially when the Garand won't work with the bullet you want. The M2 Ball bullet could work as a 'universal', including in the carbine, but it would help if that could at least be modified by a steel insert to lower the weight.
 

Deleted member 1487

Someone is getting there. :evilsmile:
If you really wanted to go that deep you could pull a CETME and fill half the M1 Ball bullet with plastic and the back half with lead, but that complicates manufacturing and eliminates the scales of economy you get from having one bullet shape/type.
 
Heavy 30 carbine found on net, for Ruger Blackhawk 150 grain
First load,
Remington cases
Fed #200 small magnum pistol primers
13.2 grains of H110
RCBS 30-150-cm
OAL 1.715
Average velocity 1223 fps
Standard deviation 15 fps
accuracy seems good but I have not bench tested.
Cases nearly fell from the chambers.
 
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