OAL is OAL, and is just a guide, and not too critical. Better too short than too long, tho. My revolver will function with loads longer than those recommended in my loading manuals. If I go too long, the cartridges bang against the cylinder throat, and I have to push each one in, if they're not too long.

That method is recommended by one of the cast bullet gurus on another site, as promoting best accuracy for cast bullets. I couldn't say for sure, but he believes it!

IMO, that just wastes time in an IPSC match, so I seat them a little shorter, so they will go "clunk" when I drop them into my cylinder. They may even bounce a little , giving two clunks. I'd rather have a little looser fit than worry about whether they need a push to close the cylinder.

That being said, I crimp all of my cast bullets in the crimping groove, but not too much, so the case mouth may become just slightly swelled, and refuse to chamber. I roll them into the cannelure of those jacketed bullets that have 'em, with what I think is a medium crimp, and don't worrry.

I firmly taper crimp non-cannelure bullets like the Hornady or Speer swaged, or Berry's plated bullets, coming close to recommended OAL.

I try to standardize everything I can. It saves time at the bench.

Now which crimp is better for auto loaders rolled or tapered?

IMO, taper crimp for autos that headspace on the case mouth.

Gidday Wiersay old mate.

For Auto Loaders there is only one crimp mate...taper. As Punkin says....auto loaders headspace on the case mouth mate.

Cheers, Vince

Yeah!!! What they said!!!


I’ve heard of guys using a taper crimp for their revolvers claiming lower extreme velocity spreads and better accuracy.
I never tried it cause I could never find the proper size bullets w/o a cannular

Anyone else hear this one ???

I don't think I'd try it with any revolver that kicked much.

One note here... OAL is pretty important in small cases, like a 9x19mm, because if you seat the bullets too short you are reducing the size of the combustion chamber and increasing pressure.

chambered221 wrote:

I.ve heard of guys using a taper crimp for their revolvers claiming lower extreme velocity spreads and better accuracy. I

Yep: I have heard that, and tried it, but haven't had the experience. Probably my loads aren't "manly" enough.

Like Punkin said, a heavy recoiling revolver may overcome a taper crimp, or even a light roll crimp, causing the bullets to move forward under recoil, jamming the cylinder. Not good!

And yeah, too little oal will reduce combustion space and may increase pressure, but it will take more than a few thousandths, imo.

I guess I should have mentioned it was for low to medium velocity loads for target work!!!

Sniper, it may take more than a few.......but with a 9x19 things happen quick !!!

You change average velocity by 15- 30 fps by nothing more than a ¼ turn of a crimp die, by adding a tenth grain of powder or by seating another .005-.010 deeper.

This is some good sht.

Now her is another one for the great pot of knowledge. I have heard of guys not crimping at all. Why is this??? What would be the advantage????

The reason for crimping is to keep the bullet in place while the gun is under recoil.
When slow burning pistol powders like H110 and W296 are used in a revolver the crimp also creates resistance to give the powder the necessary time it needs to achieve optimum burn before the bullet is released.
In a gun like a T/C single shot the crimp is not needed with these powders because the gases aren’t escaping through a open cylinder.
In many applications one may state that they are crimping when in fact they are only turning the flare back in that was previously created to allow the bullet to be inserted.
With most auto’s and low to medium velocity revolver loads it don’t take much to keep the bullet in place.

What ^^he^^ said! I always crimp revolver loads. With autos I at least turn the flare back in, and usually "snug" it some.

chambered221 wrote:

I can no longer get the bullet I used in my 9mm!!! Looking around for a replacement I see no one list OAL for lead or plated bullets. I have always used the manufactures listed OAL for my auto-loaders. So the question is, How do you determine your OAL for your auto-loaders?

Hodgon, LEE, etc. have COL per (some/most) bullet type.

Watch it with the seat depth on the high-end.

I roll all my revolver crimps.
Plinkers get it done during/at the seat die (light 'roll').
Snappy defense/full power stuff gets a firm squish at the FCD.
Ya might be suprised how easily crimps get jumped in revolvers.
Shoot 4, yank the other two and check sometime. Some do some don't. Same is why you do a 'tactical reload' between ' fur 'n fang threats' w/ full power revolver stuff.

Auto's get the correct taper for the recipe.

Plated stuff usualy prints 'legs' when over-crimped.

NO BOOMERS MR. 221.