Jam or no jam to me depends on the bullet design. A self aligner like the MP 30 sil I wouldn’t jam. The 30 XCB I would have no problems with a jam or a very short jump.
If you are gonna jam then by God jam em. Don’t go for .003 jam or something like that. A small variance on OAL or bullet nose diameter would mean one is jammed and the next may not be. By jamming them .010 or more means you have a jam for ALL of them.
By the same token when I jump I want .010 or more. Same rationale.
Yes, the BR guys with jacketed use small jam and jump numbers but they are using very precisely made bullets, fresh throats, and very tight chambers. We ain’t talking that here.
If you are gonna jam then by God jam em. Don’t go for .003 jam or something like that. A small variance on OAL or bullet nose diameter would mean one is jammed and the next may not be. By jamming them .010 or more means you have a jam for ALL of them.
By the same token when I jump I want .010 or more. Same rationale.
Yes, the BR guys with jacketed use small jam and jump numbers but they are using very precisely made bullets, fresh throats, and very tight chambers. We ain’t talking that here.