M2 Ball

[akinswi]

I wouldn't call it a controversy...just tactics changed and the M1906/M2 round was primarily intended for training while the AP was the primary combat ammo.

The M1 was very accurate but also expensive to make.

What I dont understand is the 308 M1s use 1/12 twist and the 30-06 M1s use 1/10. The 1/12 is more accurate with the 150 grain projectiles maybe they didnt under twist rates as well back then , the M1 ball with its longer bullet profile worked well with the 1/10 but they stopped using it in the 30s. I have also never seen an M1 barrel chambered in 30-06 with 1/12 always 1/10 Im sure there were some made? im assuming

 

[Jeremy2171]

What I dont understand is the 308 M1s use 1/12 twist and the 30-06 M1s use 1/10. The 1/12 is more accurate with the 150 grain projectiles maybe they didnt under twist rates as well back then , the M1 ball with its longer bullet profile worked well with the 1/10 but they stopped using it in the 30s. I have also never seen an M1 barrel chambered in 30-06 with 1/12 always 1/10 Im sure there were some made? im assuming

1/10 is the left over twist from the old M1903 220grn bullet. No reason to change the twist as it work well enough.

The 147gr M80 boat tail liked 1/12s better as it was a shorter bullet (usually).

 

[44 AMP]

1/10 is the left over twist from the old M1903 220grn bullet. No reason to change the twist as it work well enough.

Actually, the twist rate was for the 220gr bullet in the .30-40 Krag, which was retained in the .30-03, and worked well enough for military and general sporting use when changed to the 150gr bullet in 1906.

Remember, there are two basic approaches to rifle accuracy. One is to use what gives the very best possible results, and the other is to use what gives acceptable results (or "good enough") and the general military is almost always in that group.

Works good enough vs the best I can get. Civilian gunmakers also face this, and deal with it by providing both to the customer, whenever possible and practical.