Seems to me, the issue is either the ammo or the chamber. I think at this point it's like beating a dead horse when it comes to testing different loads. There have been numerous people testing numerous barrel and ammo combinations and it seems not a single person can come up with a good solution to shoot the heavy bullets. Twist rate doesn't help, nor does load. Could it be that Federal has a bad chamber? Maybe the 90 grain bullets from Sierra just aren't working? I just feel if it had been an issue beyond those that one of the various manufacturers and/or individuals would have been able to solve the issue already. Seems weird that manufacturers are making statements before Federal themselves have spoke a single word about it.