It is interesting, the 100y groups I am getting with this Lyman Great Plains Hunter replacement barrel are not as good so far as I would have expected. My old barrel was the RB 1 in 60 twist, and it shot the TC maxi bullet well. 100Y accuracy was 2 -3 inches with that old barrel. I have NOT exhausted all loading possibilities, but so far, 4 to 4.5" 100y groups are the norm. I have used powder charges from 70 to 90 grains. I would think something in there should click.
I also changed out the supplied nipple with large 0.042" hole, for the smaller Ampco.
These Hunter barrels are twisted faster than I would like at 32 twist, but I still think it should shoot better than it does. I think the hunter barrels are set up for the sabot and smaller 44 or 45 sub cal pistol bullets. I don't want to hunt with pistol bullets but I will try them just to see the accuracy - after I return from my hunt this week to see if this holds true!
Opening day here in the high country is today, but I will wait until Monday and all the weekend warriors are done.