I shot this target today at 50 yards with a Ruger bolt action 308 using lead bullets I cast several days ago. The alloy is supposed to have a hardness of 18, and they were gas checked. The bullets were the same Lyman 173 grain #311041. The cases were the same. The primers were the same. The rifle was the same. The powder was different between load A and load B. Load A was 25 grains of IMR 4227. That should produce a MV of just below 2,000 f/s. Load B was 36 grains of IMR 3031. That should produce a MV of a bit less than 2,300 f/s. Both loads were about midway between min and max for those powders.
Load A was pretty good. The target has three A groups. A1 was shot at the piece of paper. A2 and A3 were shot at different holes that had been shot into the target.
Load B was terrible. The point of aim for B was a piece of paper stapled to the target. The B hits are scattered all over the target and show keyholing.
I suppose B was just going too fast for the bullet even though the Lyman Cast Bullet Handbook showed that bullet going up to about 2,700 f/s.
Live and learn.
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