Pushing back in a slight crimp jump

[gonoles_1980]

I've had some heavier loads crimp jump just enough to keep from loading in the revolver barrel. I just push this back in a little and then fire. Any reason I shouldn't do this.

 

[jwrowland77]

I would think it would cause a higher pressure if you didn't get the bullet right back to where it should be seated (where you had them seated prior to jump)

Sounds like you need to adjust your crimp so you don't have to keep pushing the bullet back in.

 

[Blue68f100]

Sounds like you may have low neck tension and/or increase your roll crimp. With some heavy Mag loads require that you use a heavy roll crimp.

 

[gamestalker]

I had a first experience years, actually decades ago with 44 mag. or .357 mag, it was one or the other? I discovered that the trick to making sure they stay put is to crimp over the bottom edge of the canelure. It prevents inertia from allowing the bullet to move forward at all under recoil, so it can't jump free of the crimp.

As for just pushing them back in and firing them, I see no real problem with that as long as you don't push them in beyond the canelure, as that could have the potential to cause a pressure problem.

GS

 

[gonoles_1980]

I barely push them back in, just enough so the cylinder will close. I don't have it happen often, usually on the high end when I'm testing a new ladder load.

 

[Mad Chemist]

You need to improve your technique so that pushing the bullets is no longer necessary.

 

[codefour]

The Speer Manual has a section dedicated to crimping for the heavy magnums. On some of my .454 and .460 Mag loads, I had to crimp heavily where the crimp looked like it folded the brass over the canelure to prevent bullet jump. The heavier bullets are more prone to bullet jump as well.

As gamestalker stated, crimping over the bottom edge of the canelure helps too.

 

[gamestalker]

I load full tilt exclusively with H110/296 for all my wheel guns cartridges, and I haven't had one jump crimp since the days of old. That was when I learned the proper technique of using a good full roll crimp, placed over the bottom edge of the canelure.

Additionally very important, and IMO, absolutely necessary to achieve a consistent crimp, and for the crimp to be located in the right / same place on the canelure, the brass needs to be trimmed to the same near exact lengths. Other wise, crimp location of the canelure will be all over the place. +/- .001" is ok, but more than that and you'll have under / over crimped mouths, and your crimp location in relation to the canelure will vary greatly as well.

You'll be just fine, it's just takes a little practice and some attention brass prep detail.

GS