The northern Precision bullets I have are closer to 451 I'm afraid you're going to have a hard time using them in a bergara barrel, I can use them in a cut rifle Brux,,, I have not been able to use them in a McGowan,, I'm referring specifically to his 270 pinpoint and he has a 270 bonded which I'm really impressed with the accuracy of you'll find the sidewall contact on that particular bullet is minimal there's just a small band at the bottom of the bullet that will size. Some of his other bullets are not like that still if it were me and I had to order coming from him and I was going to try them in a cva, I would get bill to knurled them up ,, give you a little bit more sizing flexibility,, he has a nice 350 grain spire that shoots really good with black horn and of course the 400 grain bullet I think you might have noticed I've been shooting, I know those are probably a little big for the 22 twist that you're shooting but you might be surprised I would try them with black horn got to get him to add a few of those to your order the 400 gr with a baffle brake and 84 grains of Black Horn is not bad at all recoil is very tolerable and accuracy for me and a 18 twist has been phenomenal.