I'm really amazed at these folks that use .444 brass. Maybe it works because of the slanted edge of the rim.
But 303 Brit and 30/40 Krag are supposed to work. Notice they have almost the same diameter and thickness of rim as the .444. But then, the 30/40 has a slanted rim edge.
I have never tried 444 brass, but I have tried 303 and 30/40 in 4 different shotguns, and since three of 'em were SxS, that means seven different barrels. None of the guns would close. Thinning the top of the head, which would be easier, would make the primer pocket shallower. So you'd have to thin the rim from the backside. I tried it. Pain in the butt. That's why I was so happy that the actual 410 brass became available.
My brass cases, in 12 gauge, 16 gauge and 410, all use LP primers. Pistol, not rifle, and there is plenty of fire there to set the powder off.
Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297
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