Re: Need some advice
Ian, I would suggest you go with a much slower vel. load. That load using Green dot may be a good choice.
I have used those electroplated bullets before in handguns. Basically a cast bullet with a few thous of copper. No where near as tough as a jacketed bullet.
At the high vel of the loads you have been trying, the bullet is pulling itself apart. This bullet was designed for the 30 carbine so if you keep vel in that range you should be ok.
Try cast bullet loads using IMR SR 4759 or the AA equivalent. Probably work best with vel. under 2000fps. H4227, Unique, Re7, HP38/Win231, H4198 are all possibilities too.
Been playing with some cowboy cast bullets in my 308 and have been getting some pretty good results at 100yds (2" groups). Fun to plink with these at "long range".