Crimping really important?

[xibunkrlilkidsx]

Is doing a crimp on 223(in AR) 9mm(RugerSR9) 45acp(1911) needed. Wanting to expand my reloading universe, been doing 308. Just wondering if i need the spend the few extra dollars and get the factory crimping dies with everything else...This is purely range, plinking stuff. no hunting.

http://www.midwayusa.com/Cart, die sets im looking at

what say yee reloading gods?

[Shoot-it]

I don't think so.
When I reloaded for my (carbon -15) sealed mag well ar-15 I did not crimp and I reloaded hundred of rounds and never had a problem.

[xibunkrlilkidsx]

I don't think so.
When I reloaded for my (carbon -15) sealed mag well ar-15 I did not crimp and I reloaded hundred of rounds and never had a problem.

I rmember reading something ehre, yes everything on the internet is TRUE!, about needing to crimp rounds for auto loaders because the recoil would rattle the bullets out? but its an ar15, WTF is recoil.

read it a while ago could remember the exact wording.

[sequoia_nomad]

You should definitely be crimping your semi auto handgun rounds to avoid bullet setback and dangerously excessive chamber pressures. You shouldn't have to buy a separate crimp die, it is the same die as the seater in all 3-die sets I've ever seen.

[stphnman20]

You don't have to crimp.

I crimp.. But just lightly with a FCD.

[sonnyt650]

Nothing to do with hunting AFAIK...

Notice your bullets ride up on a feedramp to enter the chamber: as the case is being stripped and pushed into the chamber that feedramp produces an opposite force pushing the bullet into the case . The Lee FCD does a "taper crimp" as opposed to a "roll crimp", and a taper crimp is suggested for the 9mm and 45ACP in the Lyman manual to avoid bullet setback. The taper crimp allows these rounds to headspace correctly where that edge isn't rolled into the bullet which changes the length of the case. BTW: if you have a Lee Pro 1000 you can't use four dies anyway so this is moot.

[J-cat]

A taper crimp improves reliability of rounds that have had their case mouths belled during the reloading process. You need that taper crimp to remove the bell that will snag on things on the way to the chamber.

A taper crimp does not prevent bullet setback during feeding as it has nothing to wedge against except a smooth concave surface.

[GeoffLinder]

You NEED to use a taper crimp on any straight-walled pistol case as you always bell the case mouth for bullet seating and at the very minimum you need to remove this belling. Crimping per se is not really needed for most semi-auto pistol rounds. A roll crimp may be needed for hefty revolver calibers to prevent bullets backing out of other rounds in the cylinder under recoil.

Crimp on a bottleneck rifle case is not really needed if the expander ball on your size die is making the case mouth the right size. Case neck tension alone is plenty good for rifle loading EVEN in semi-auto rifles. Crimping can be done if you feel the need, but always use a taper crimp on rifle cases. Crimping rifle IMHO is best done to reduce SD from unsorted brass by uniforming bullet release tension than for any other reason.

Lots of folks worry about bullet setback in semi-auto's, I find that to be an old wives tail for the most part. Many well known and very knowledgeable multi-gun competitors don't crimp .223 for their race-rifles and have a long track record of no issues.

I tested setback on my reloads compared to factory ammo a few years back. Factory PMC .223 and my 55 grain reloads both passed the push as hard as you can with your thumb test and neither changed OAL. After 2 dozen test chamberings from a magazine no reduction in OAL was found for either round.

BTW, my experience on this runs to many, many 10's of thousands of .223 rounds over a couple of decades

[sonnyt650]

Disclaimer: the only experimentation I've done is for my own ammo, while the only setback failure I've seen is with someone else's gun show purchased reloads. The failure was in a 9mm handgun and prevented extraction of the live round until a cleaning rod was pushed from the muzzle against the bullet and the slide worked, so some of the setback could have been from the cleaning rod.

A taper crimp does not prevent bullet setback during feeding as it has nothing to wedge against except a smooth concave surface.

The wedge into a cannelure design isn't the only mechanical way of keeping things from moving. My reasoning is that the taper crimp pushes the case neck up consistently against the bullet providing additional surface area for static friction. Simply removing the bell doesn't increase neck tension where the case was flared out, so the "load bearing area" is reduced and the total friction is reduced.

[J-cat]

A taper crimp does not increase neck tension either. Brass springs back.

[Fiveohmike]

You NEED to use a taper crimp on any straight-walled pistol case as you always bell the case mouth for bullet seating and at the very minimum you need to remove this belling. Crimping per se is not really needed for most semi-auto pistol rounds. A roll crimp may be needed for hefty revolver calibers to prevent bullets backing out of other rounds in the cylinder under recoil.

Crimp on a bottleneck rifle case is not really needed if the expander ball on your size die is making the case mouth the right size. Case neck tension alone is plenty good for rifle loading EVEN in semi-auto rifles. Crimping can be done if you feel the need, but always use a taper crimp on rifle cases. Crimping rifle IMHO is best done to reduce SD from unsorted brass by uniforming bullet release tension than for any other reason.

Lots of folks worry about bullet setback in semi-auto's, I find that to be an old wives tail for the most part. Many well known and very knowledgeable multi-gun competitors don't crimp .223 for their race-rifles and have a long track record of no issues.

I tested setback on my reloads compared to factory ammo a few years back. Factory PMC .223 and my 55 grain reloads both passed the push as hard as you can with your thumb test and neither changed OAL. After 2 dozen test chamberings from a magazine no reduction in OAL was found for either round.

BTW, my experience on this runs to many, many 10's of thousands of .223 rounds over a couple of decades

I went through the same dilema on my AR10 .308 build. I posted here, peops said its not needed..... 500 rounds later of hand loaded, non-crimped rounds and no issue.

[sonnyt650]

A taper crimp does not increase neck tension either. Brass springs back.

Actually for 40S&W I'm able to use an inertial bullet puller (hammer) method if I haven't crimped, while it doesn't budge if I've taper crimped. There's something more going on there, at least for me.