.460 S&W Issue on a 550

[jaymo]

I am getting 1 or 2 misfires per 10 rounds on my .460 mag loads whether using new Starline brass (which calls for large rifle primers) or the subsequent reloaded cases. These misfires will normally fire ok on a second try, suggesting the primer isn't fully seated on the first firing. The primers are flush with the case after I seat each firmly a couple of times with the press handle. The shell plate is as low as it can go and still rotate, and the primers 'feel' as if seating ok. Winchester primers seem a tad better than CCI, but the problem remains. I have shot 40 rounds of factory ammo without a misfire, so I don't think my .460 XVR revolver is the problem. Most of my reloading is for other calibers using large pistol primers, and I have no problems with those, so I believe my adjustments are correct. Any thoughts or anyone else having issues with large rifle primers on a 550?

[digrazir]

I think you are headed in the right direction by noting the primers may not be seated deep enough. My Sinclair priming tool will seat the primers deeper than my Dillon press. You could maybe pickup or possibly borrow a hand priming priming tool and try seating the primers a little deeper taking care making sure you don't crush them. Ray