Thanks for the responses. I appreciate the very useful and encouraging information. I'd never thought about rifle 'twist' during recoil. When I shot the heavy bullets that grouped to the right, I was resting the rifle on sandbags with virtually no grip to counter the torque. I must try holding the rifle tight next time to see how much of a difference it makes. That info certainly helps to dispel some of the mystery.
I like the look of that Lyman 358429. Thanks for the suggestion. I will keep my eye out.
I am using what I believe to be fairly soft lead. I got a lot of leadlight 'came' scrap which I made ingots from. I do add a little tin in the form of skinny leadlighting 50/50 solder, but I suspect it doesn't always mix in well.
Yep, those .357 cartridges with lead projectiles remind me of .22 cartridges as well. I like the look of them.
Here is a picture showing three of the projectile types I have. On the left is a Speer swaged lead semi-wadcutter hollowpoint. I bought these from Reloaders. They didn't group consistently for me when using Trail Boss powder, but the one group I recently tried with APS350 grouped well enough for close-range subsonic hunting. I haven't taken them hunting yet. The middle bullet is the home-cast Lee 358-158-RF. This performs well. On the right is the new Lee c358-200-RF. The meplat isn't so big on this, but it should be better than a pointed nose.
Here is another question related to accuracy. Why do some powders seem to work better with certain projectiles at similar velocities? Can a faster powder sometimes deform the back end of a bullet before it gets underway maybe?
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