To Crimp or not to Crimp? That is the question.

[Delmonico]

To be truthful I've found a good taper crimp grips the bullet far better than a roll crimp based on what it takes to remove a bullet from a loaded round.  The tighter you set it the better it grips, a roll crimp can be set up to crimp too much and this pulls the sides away from the bullet.  This can happen esp it you get the case that is a bit longer than the others.

[Longshot Lil]

We're fairly new to reloading, and we were told by someone that has been helping us along with questions, that you can crimp or not.  We've fired 600 or so rounds that were not crimped (.38 special from .357 mag's) and have had no problems.  I shot nearly all bullseyes, hand holding my Marlin 1894 at 25 yards with them.  We do have a taper crimp die coming and will be crimping all future loads, but we've fired these rounds from 3 different .357 lever action rifles as well as Ruger Vaquero and Blackhawk.  No squibs, and accuracy was pretty good. 

[Shotgun Franklin]

With a lever action rifle you have a compressed spring pushing a line of ammo. If the bullet is ever going to push back into the case that's the most likely time it'll happen.  If that should happen and that round feeds into the chamber and is fired then the Shooter will have a rather unpleasant explosion between his hands. Not a good thing.

[Cliff Fendley]

We're fairly new to reloading, and we were told by someone that has been helping us along with questions, that you can crimp or not.  We've fired 600 or so rounds that were not crimped (.38 special from .357 mag's) and have had no problems.  I shot nearly all bullseyes, hand holding my Marlin 1894 at 25 yards with them.  We do have a taper crimp die coming and will be crimping all future loads, but we've fired these rounds from 3 different .357 lever action rifles as well as Ruger Vaquero and Blackhawk.  No squibs, and accuracy was pretty good. 

You couldn't pay me to take that chance in a rifle with a tubular magazine. Consider yourself lucky.

[Longshot Lil]

Point well taken...  We only load a max of 5 in the rifles (even when practicing at the local range, because they only allow a max of 6 to be loaded at one time anyway), so the cartridges aren't compressed that much because the spring isn't compressed fully.  We ARE getting a taper crimp die, it's on the way, and all future rounds will be crimped, in fact we've got a bunch loaded that all will be crimped as soon as the die arrives.

[Charlie Bowdre]

LL
God is on oyur side for sure.

Welcome to the game  Lods of fun
But always be safe .
Enjoy
Dutch

[Wayne the Shrink]

Crimping in revolver rounds is for one reason and only one reason.  Without a crimp the recoil from previous rounds can cause the bullet to protrude beyond the cylinder face and bind up the revolver.  If your loads are not powerful enough to cause this problem, and apparently they are not, you don't need to crimp.  Light wad-cutter loads were almost never crimped.  If your revolver is more accurate with a crimped round vs an uncrimped round that's fine and specific to your revolver. 

Crimping in semi-autos and in lever guns is to prevent bullet setback and increased pressure, perhaps fatal to the gun pressure.  These need always to be crimped, no matter the type of crimp.  Both work.

Magazine fed and single shot rifles are different.  I have one that is much more accurate with crimped loads and another that is more accurate with uncrimped loads.  In these rifles there are a lot of variables to work out, including max cartridge length allowed by the magazine rather than by the chamber.  This is sometimes the limiting factor unless you are willing to make the gun a single shot.

[Cliff Fendley]

I good heavy crimp in revolver rounds can be beneficial for more than just holding the bullet in place under recoil. I found out a long time ago in the big boys (44 mag, 480 Ruger, 454, 460) that I get better accuracy and more consistent velocity with a heavy crimp.

[Delmonico]

I good heavy crimp in revolver rounds can be beneficial for more than just holding the bullet in place under recoil. I found out a long time ago in the big boys (44 mag, 480 Ruger, 454, 460) that I get better accuracy and more consistent velocity with a heavy crimp.

What you really want is called bullet pull, it involves the force required to move the bullet in the case.  Bullet pull is a funtion of both a crimp if used and how tight the bullet fits into the case. 

A roll crimp that is too heavy will actually pull the case sides away from the bullet.  That's the reason I use a taper crimp, if you get a case that's slightly longer than the rest the taper crimp just snugs the case against the bullet even more.  And yes a good taper crimp will roll the case mouth into the crimp groove if there is one present.  Good bullet pull insures good ignition.

[longinosoap]

Last week at our annual match, the first day I shot the first two stages clean. On the third stage shooting the 73 in 45 LC I had a bullet fall into the case in the magazine which caused a jam. Had to take 7 misses. Went home and tightened the Lee crimper and recrimped all rounds. No problem the second day. Lesson learned.

[rickk]

Wayne,

Crimping can do more that you think.

If you want to make some squib loads, load up some 357's with H110 and don't bother to crimp.

Rick