What if the .276 Pedersen had been adopted?

[furetto7]

How different would the small arms of Phase II of the First Global War (AKA WWII) been if in 1932 then Army Chief of Staff Douglas MacArthur had approved adoption of the Garand in .276 Pedersen instead of having it re-designed for the .30-06?  There would have been a more significant cost to either re-design or re-chamber other rifles and machine guns in service at that time and money was tight because of the depression.

The .276 Pedersen (7 x 51mm) would have weighed less and been more controllable in full and semi automatic fire than the .30-06 (7.62 x 64mm), there was no real need for a round with a range of 2,000 yards in a war where most combat was at 300 yards or less as had happened during most of Phase I of the First Global War (AKA WWI or the Great War).

What say you, would things have been that much different if we had gone to a more intermediate round thirty years earlier?

[Mike Irwin]

Well, according to some things I've read on line...

Had we adopted the .276 and dispensed with the sainted .30-06, Satan would himself have risen, sided with the Nazis and Japanese, and we'd be speaking Japanese on the west coast and celebrating Fuhrertag on the East coast. 

Realistically, I don't think there would have been much difference at all. I suspect that for automatic weapons use the .30-06 would have been kept due to economic reasons, with the intention of making a "slow changeover" that would have been swamped by World War II. 

Not that big a deal, actually, as the only automatic weapon in widespread use that used a magazine was the BAR, everything else used belted ammo, so the supply logistics probably wouldn't have had been that bad.

The only real difference is that we might never have gone to the 5.56 as our primary cartridge, and likely would have been a LOT more receptive to the British 7x43 round developed in conjunction with the EM-1 and EM-2 bullpups.

[Jim Watson]

Agree on the logistics.  Belt up most of the stock of .30 for machine guns, keep one production line open to feed them.  Use the Springfields and BARs for training, home guard, and emergency reserve. 

Riflemen get .276.  And a .276 LMG in lieu of BAR and 1919A6. 

So, then what?  Would a .276 carbine and some SMGs have spared us the need for the M1 Carbine? 

Would we have gone with the 7mm British?  I don't think so, not enough smaller and lighter. 

We might well have still had the 5.56. 

 

[geeorge]

But 30 ought six sounds so cool

[ewell44]

Intradesting...

Alas just one in a long line of failed intermediate caliber adoptions.

 

 

[JohnKSa]

I think that there's a good chance we might still be using a 7mm round at this point had we gone in that direction with the Garand.  The decision to stick with the .30 caliber due to cost considerations resulted in the .308 (7.62x51) being developed as a .30-06 replacement after WWII.  It's pretty much a given that if we had already been using a 7x51 after WWII, there would have been no point in the .308--they might have gone to something like a 7mmx39 or 7mmx40, a rough analog of the Russian 7.62x39.

It's conceivable that such a caliber would still be in use.  The whole stupidity of the military playing games with the M14 selection and their refusal to accept anything other than a .30 caliber was part of what drove McNamara to finally say Enough is enough! and switch them wholesale to the M16 and the 5.56NATO. 

Edited October 15, 2017 by JohnKSa

[AK_Stick]

WWII would have been the same, save a few minor changes for a 7mm barrel on most guns. M1's were made with 276 Peterson chamberings.

5.56 likely still would have replaced it, as its smaller, and can be had in the M-16.

 

May have replaced our 308's.

[JohnKSa]

5.56 likely still would have replaced it, as its smaller, and can be had in the M-16.

Remember that the first AR wasn't the AR-15, it was the AR10 in .308.  It's likely that if the military had been using a 7mm round, the AR-10 would have been chambered for that round and not the .308.  We might very well have ended up with an M11 firing some sort of a short 7mm round instead of the M16 firing the 5.56.

[Clancy]

A change to a different rifle caliber would have made no difference at all. It was American manufacturing power, combined with Stalin's willingness to accept horrific casualties that won the war.

[AK_Stick]

On ‎10‎/‎25‎/‎2017 at 8:22 PM, JohnKSa said:

 

Remember that the first AR wasn't the AR-15, it was the AR10 in .308.  It's likely that if the military had been using a 7mm round, the AR-10 would have been chambered for that round and not the .308.  We might very well have ended up with an M11 firing some sort of a short 7mm round instead of the M16 firing the 5.56.

7x51, is still much larger than 5.56x45. Its pretty likely we still would have ended up going to 5.56, as the trend was to smaller, lighter, more controllable rounds.

[JohnKSa]

Quote

7x51, is still much larger than 5.56x45.

Yes it is.  And they might have stuck with it, after all, the FN-FAL was quite popular in the 7.62x51 through the end of the 20th century.  But I don't think it's likely since everyone was looking to go to shorter rounds after WWII.

Germany came up with the shortened 8mm, we came up with a (barely) shortened version of our .30 cal and the Russians came up with a shortened version of their .30 cal.

Quote

Its pretty likely we still would have ended up going to 5.56, as the trend was to smaller, lighter, more controllable rounds.

I agree that the trend was to smaller rounds, but up until McNamara finally reached his breaking point, the trend had been to come up with more compact versions of cartridges which still used the same bore size rather than to go a completely new bullet diameter and cartridge.

I think it's likely that had we ended WWII with a 7x51 (that was the "What if" in the thread title), it's more likely that we would have eventually ended up with some sort of a shortened 7mm (obviously not the 7x51--but something shorter than the 7x51) rather than going with a 22 caliber round. 

Edited October 31, 2017 by JohnKSa

[Cheygriz]

We had billions of rounds of .30-06 in the war reserve ready to go, without re-tooling and building new production lines.

The .30 made our machines guns, rifles and SAW ammo compatible.

 

The alleged ballistic advantage of the 276 IF INDEED ANY AT ALL, could not overcome that.