I shot the 63 gr Sierra SMP's in my 1 in 14 twist Swift (extremely accurate). It wouldn't quite stabilize the 60 gr Nosler Partition, but it was close to doing it. It didn't come anywhere close to stabilizing the 65 gr Sierra GK. I'm thinking that it might stabilize that new 64 gr bonded Nosler, but maybe I'm just kidding myself. There was a guy on another forum that said he'd send me some of the bonded Nosler's, but he never did. Dang.
