Out of curiosity, last night I weighed and sorted a batch of .575 balls cast from a single cavity Lee mold, which is listed as 285 grains.

Here's how they broke out.

9 (3%) were under 283 grains (discarded those)
56 (20%) were 283 to 283.9 grains
84 (30%) were 284 to 284.9 grains
80 (29%) were 285 to 285.9 grains
46 (16%) were 286 to 286.9 grains
5 (2%) were 287 grains or more (discarded those)
-----
280 TOTAL

The balls were from two different casting sessions, one for about 200 balls and one for about 80. What I found interesting was that every one of the balls in the 283 - 283.9 class were from the second session.

Did you ever measure the diameter of your balls to see if all that tumbling changed things? (I can't believe I asked that)

It won't matter, unless you are shooting knats at 100 yards...

Didn't think of doing that Cayugad. Too late now though. I don't have any untumbled ones left.

I agree nchawkeye. But what the heck - it can't hurt, and us old retired guys have lots of time to do things like that.

My concern was if I tumble some .530 ball and it reduced the diameter, they load easy now. So would I need different patches? Also I was just curious.

I just measured a dozen of the tumbled balls. Almost every one was .576 - very consistent - with two or three very slightly larger - maybe .5765.

Now I really wish I had some untumbled ones to measure. Would they be closer to .575 (as the mold box states)? The tumbling leaves a textured surface on the ball, rather than the smooth surface left by the mold. So I'm wondering if tumbling increases diameter slightly - as with knurling.

It will be interesting to see how well they shoot.

Mother's day family activites will pretty much kill any chance for a shoot this week end. But the following week end I'll be at the lease with the .58 GM barrel mounted on the refinished Hawken stock and a TC hunter peep sight. You will be seeing a range report.