The Firing Line Forums - View Single Post - Accurate bullet for M-4

me26245 · July 28, 2011, 11:03 PM

Depending on the barrel twist rate you should be able to use any bullet weight from 45gr to 77gr.

1 in 9 twist rate, bullets between 45-62gr should work well, however the 62gr bullets may not stabalize fully.

1 in 7 twist rate, will work better with bullets from 55-77gr with bullets 62gr and heavier working better.

Even if your bullets don't have a cannalur (crimp groove) you need to put a good crimp on reloads to prevent bullet setback, which could cause a over-pressure problem.

If your reloading for a bolt gun crimping is not as critical and may not even be required.

July 28, 2011, 11:03 PM	#3
me26245 Member Join Date: April 3, 2008 Location: midwest Posts: 42	Twist Rate Depending on the barrel twist rate you should be able to use any bullet weight from 45gr to 77gr. 1 in 9 twist rate, bullets between 45-62gr should work well, however the 62gr bullets may not stabalize fully. 1 in 7 twist rate, will work better with bullets from 55-77gr with bullets 62gr and heavier working better. Even if your bullets don't have a cannalur (crimp groove) you need to put a good crimp on reloads to prevent bullet setback, which could cause a over-pressure problem. If your reloading for a bolt gun crimping is not as critical and may not even be required.