how flat is flat-nose for tube mag?

[J Miller]

No on convex noses. As far as I can remember, they had perfectly flat noses. As for the possibility of a high primer, given what happened, all I can say for certain is that I can't say absolutely that there wasn't one. I primed each case with a Lee Hand Priming tool, that had always given me good results with more than flush seating, and I usually check each round with my finger for flush-ness, but??? There's always the possibility that a bad one slipped through. The moral to the story is, if in doubt, recheck the whole lot again.

I have recently noticed that one of my 2 Lee Priming Tools (the one set up for large diameter primers) is not consistently seating primers deep enough. I have to fully seat these primers using the priming arm of my press. Doing this, primers are always seated below flush.

Muskeg13,

Hopefully someday the cause of this incident will come to light. It will make me more conscious about the way I load the ammo for my lever guns. That's for certain.

Take your Lee Auto Prime tool apart and inspect the bearing surfaces. If they are worn replace them. Then keep all bearing surfaces lubed. Also I seat my primers twice. Seat them once, rotate the case 180º and seat it again. That way I make certain it's below flush all the way around.

When inspecting seated primers I use the tips of my fingers. Been doing it so long they are educated to what a below flush primer feels like. But as I've gotten older I've found my fingers seem to loose sensitivity after a while so I have to prime smaller batches.

Joe

[NMLRA Guy]

I've used several progressive presses and sooner or later mashed a primer nearly out of existance. No explosion. And, yeah, I know that ain't a sharp rap. That having been said, I think that if you can get a slamfire on a primer (documented, I think) in an M1-A or Garand, it is possible, though highly improbable unless it is a high primer.

[dakotashooter2]

I would be interesting to see what the anvils of the primers looked like. What I'm wondering is if the force generated by the first detonation would be enough to cause the anvils on other cartridges to "set back" into the priming compound and ignite it? Or the possibility of hydralic force of the bullet being pushed back into the case "setting back" the anvil?

One always has to consider the possibility of a bullet tip, even flat nosed, picking up some debris that may contact the primer.

[BAGTIC]

Good reason to make sure primers are fully seated regardless of bullet style.

[BAGTIC]

Remember it would be very unusual for the tip of the bullet and the primer to be aligned due to the cartridge being canted in the tube due to cartridge taper and rim protrusion.