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Bart B. · November 2, 2013, 09:28 PM

I weigh cases for target shooting at 600 yards or further to a 1% spread in weight. About a 2.3 grain spread for my 30 caliber magnum ammo with cases about 230 grains in weight; less for .308 Win. ammo. 2 grains of case weight difference is about the same as 1/10th grain change in powder charge weight; not very significant in my opinion.

The best arsenal .30-06 match ammo with metered powder charges and a 5 grain spread in case weight shot 1/3 inch at 100 yards from good rifles in its heyday and 1 MOA at 600. As good lots of commercial .308 Win match ammo will shoot under 1/3 MOA at 100 yards and 2/3 MOA at 600 yards in well built rifles with their 3 to 4 grain weight spread, I wouldn't bother weighing cases until you shoot your stuff no worse than 1/2 MOA at 100 yards.

A dozen or so other things are more important than case weight. Near the top of the list is ensuring the bullets are a few ten-thousandths larger than the barrel's groove diameter. Exact charge weights of powder's way down the list for targets 600 yards away or less. Beyond that, a 2/10ths grain spread is about fifth on the list.

Never saw any improvement in accuracy with uniformed flash holes. Reamed them to a uniform diameter and chamfered them. Accuracy stayed the same.

November 2, 2013, 09:28 PM	#10
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I weigh cases for target shooting at 600 yards or further to a 1% spread in weight. About a 2.3 grain spread for my 30 caliber magnum ammo with cases about 230 grains in weight; less for .308 Win. ammo. 2 grains of case weight difference is about the same as 1/10th grain change in powder charge weight; not very significant in my opinion. The best arsenal .30-06 match ammo with metered powder charges and a 5 grain spread in case weight shot 1/3 inch at 100 yards from good rifles in its heyday and 1 MOA at 600. As good lots of commercial .308 Win match ammo will shoot under 1/3 MOA at 100 yards and 2/3 MOA at 600 yards in well built rifles with their 3 to 4 grain weight spread, I wouldn't bother weighing cases until you shoot your stuff no worse than 1/2 MOA at 100 yards. A dozen or so other things are more important than case weight. Near the top of the list is ensuring the bullets are a few ten-thousandths larger than the barrel's groove diameter. Exact charge weights of powder's way down the list for targets 600 yards away or less. Beyond that, a 2/10ths grain spread is about fifth on the list. Never saw any improvement in accuracy with uniformed flash holes. Reamed them to a uniform diameter and chamfered them. Accuracy stayed the same. Last edited by Bart B.; November 3, 2013 at 10:09 AM.