Just a suggestion, but you may want to think about using a lighter bullet if you want to use a solid copper style. Most of them need at least an 1800 fps impact velocity to perform consistently. Something like the 101gr HH or the 120 Lever Hammer might work better, to keep the velocity up.
If you want a heavier bullet, the 161gr Haymaker from Apex Outdoors will expand down to 1000 fps. It was specifically designed for the 300 BLK and other low velocity 30's like pistols. I've tested the Haymaker quite a bit out of a 300 BLK and a 300 Savage Encore barrel and it's worked great in both cases.