A few taps with a small brass hammer until I feel it seat fully are not the equivalent of "bashing it with a mallet." It's a safety precaution, but in any event the big ones aren't stabilizing whether I seat them hard or light. The twist is way too slow for the job for 400+ grain conicals. The fact that it's a double confounds the difficulty. By reconfiguring the sights I can get at least one barrel to shoot them OK, but the other is off paper with the same load. This Kodiak likes RB's and conicals under 275 grains. I'm just trying to find the best mid-range conical for the job.