I tried WW alloy for my .56 renegade, and the balls came out oversized, I could hardly ram them down on top of the powder. Then I tried pure lead from old pipes, and they were ok. I would guess if you used the WW alloy they dont shrink like pure lead does so you would need to use a thinner patch. Everything I have read though says use pure lead.
For really fine accuracy in a M/L you need pure soft lead. The lead has to take the imprint of the patch to get a good grip on the rifling. Wheel weight lead is hard enough that if you do get them to grab the patch you deform the nose when you POUND them into the gun. If you use PURE lead and have a good gun you should shoot just as good a group as your eyes will hold. I have severl targets with 5 shots under 2" at 100 yds, from cross sticks. If you are willing to shoot 4-6" groups at 100 try the wheel weights.
I have tried some RB cast from WW's in my .50 cal. GPR. They were difficult to pound down the bore when starting as they cast larger and are harder. But the most important thing was that they didn't shoot worth a damn. You will be much happier if you stick to soft lead RBs.
On the other hand I have heard that many shooters of smoothbore guns can get just as good accuracy with WW's as they do with soft lead. They might have to adjust thier patch thickness because of the different size they cast to, but since the ball doesn't have to conform to rifling when loaded or fired, they seam to shoot fine. The big advantage for them is that it is usually easier to find sources of cheap WWs.
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