Crimp cast boolits for auto cartridges?

[chewy]

Simple question since I'm sorta' new to castin' me own boolits. Is it necessary to crip 9mm cast boolits made from WWs? I had a couple shave some of the lead off when i was seatin' them and tried pullin' them and the little boogers wouldn't come out! Seems like I wouldn't need to crimp 'enit?:confused:

[freakshow10mm]

Same deal as with jacketed. Just remove the bell you make with the powder die. Be careful not to crimp too much and swage the bullet down. With revolvers I always put a heavy crimp in the groove, especially with my 38-215-SWC. They like to jump crimp with heavy loads sometimes.

[chewy]

Cool. Thanks Freak. I barely bell cases enough for the boolit to fit. So they be pretty snug. I think I'll shoot a few and measure whats' left in the mag and measure some that get chamered as well too before try crimpin' 'em all.

[freakshow10mm]

I tend to bell a teensy bit more than needed, but shaving bullets sucks.

[chewy]

I think I got it spot on for the various 9mm cases I loaded up. Only 3 shaved outta' abot 1700 or so. I can live with that. Haven't catsed any 158 358s' yet though. Still wanna shoot up my laser cast supply. That'll happen quick since Slick's S&W 686 post got me all in love with my 686 plus again.

[918v]

Chewy,

In terms of bullet retention, crimp is not an issue in semi-auto applications. Semi-autos do not pull bullets out of their cases and crimp does absolutely nothing for bullet setback.

In revolver applications, crimp supplements case tension. You still need both. Either one by itself is not enough to hold the bullet, unless the bullet has a fairly long shank and the recoil is low.

[Crazy4nitro]

I had bought some cast bullets for my .40 and they had a Crimp groove.
When the bullet was seated to correct length the crimp groove was well past the mouth of the case.

'Nitro

[freakshow10mm]

Might have been for the 38-40.

[918v]

Crimp grooves in semi auto pistol bullets suck.

[zdogk9]

only thing with semi autos is to get ALL the flare out the case mouth or it'll hang up with about 3/4 of the round chambered, fine line between getting this right and swaging the boolet.

[Crazy4nitro]

Might have been for the 38-40.



:)

'Nitro

[freakshow10mm]

918v, my 10mm-225-SWC has a crimp groove and it works well. Some loads in 10mm need it with that bullet.

[chewy]

I did a bunch of chambering of said 9mm cast boolits last night before bed as a means of Q&A and sure enough, boolits stayed in place like they should. I've always known about crimpin' revolver stuff, pretty much knew about jacketed and plated, but sure do appreciate all the help with cast stuff. Thanks y'all.

[918v]

918v, my 10mm-225-SWC has a crimp groove and it works well. Some loads in 10mm need it with that bullet.

Why do your 10mm loads need a crimp groove? Are you compressing the **** out of them?

[freakshow10mm]

If I don't crimp to the groove the bullets in the mag will jump crimp and jam the gun.

http://img.photobucket.com/albums/v239/freakshow10mm/Boolit%20Casting/Reloading10507004.jpg

[918v]

Aren't you messing with headspace by crimping so hard?

[freakshow10mm]

That one there was a dummy with a hard crimp to keep the OAL steady. I've crimped and fired several hundred rounds with a severe crimp like that and haven't run into troubles.

My loads are usually .420-.421 crimp. I can run up to a .424 crimp and still chamber fine. I am experimenting with my 225gr HP in 10mm. It's the same bullet above, but ran in a swaging die with HP punch.

[Hatman1793]

On page 45 of "The Glock in Competition" the author talks about self-seating bullets:
"As cartridges come out of the magazine on a Glock [or any other auto for that matter] they slam into the feed ramp before sliding into the chamber. If your bullets are not well crimped, it is possible to have them seat themselves deeper in the case --with potentially disasterous results."
"A small change in the overall length under the minimum figure causes SERIOUS changes in pressure according to Speer's research."
Always crimp auto loads.
:sifone:

[chewy]

Hmmm. I chambered a handful over and over again, measuring after each time, and there was no difference. I think they're good to go, all brass have a slight and even hump where they be seated. I'll keep an eye out anyway.

[freakshow10mm]

Crimping in auto pistols "well" means properly. Crimp enough to remove the bell and set the case mouth straight. The neck tension is built in to the internal dimensions of the case. Overcrimping will result in reduced headspace and can cause safety issues.

[918v]

On page 45 of "The Glock in Competition" the author talks about self-seating bullets:
"As cartridges come out of the magazine on a Glock [or any other auto for that matter] they slam into the feed ramp before sliding into the chamber. If your bullets are not well crimped, it is possible to have them seat themselves deeper in the case --with potentially disasterous results."
"A small change in the overall length under the minimum figure causes SERIOUS changes in pressure according to Speer's research."
Always crimp auto loads.
:sifone:

The author is an idiot.

[Anvil]

I was looking through my bullet moulds tonight and found a .38 four banger keith style mould by lyman. I'm guessing 158, I've never used it before. Will the classic Keith style bullets work in a 9mm? crimp groove, and lube groove, truncated semi wadcutter.


From the crimp groove it's .347 to the meplat, the case is .748 for a total of 1.095" The recomended OAL for 9mm is 1.169" so it looks like I'm in the clear but there's always the feeding issues. I guess I'll have to experiment to see.

[918v]

Not if the front driving band is at full diameter and wide enough to hang-up in the throat.

[Anvil]

Yeah, it's the classic revolver keith style so it's full diameter.

[918v]

Most 9mm chambers will allow .050" of bullet shank to sit past the case mouth. You could make a dummy round to see if it works.

[fredj338]

You need to flare/bell the case mouth just abit more for a lead bullet (plated too) to prevent shaving. I crimp all my handgun rounds, roll crimp for revolver & taper crimp for pistols. You'll get more reliable feeding & more consistant vel. For pistol, just enough to return the case mouht to factory spec.

[CZ93X62]

only thing with semi autos is to get ALL the flare out the case mouth or it'll hang up with about 3/4 of the round chambered, fine line between getting this right and swaging the boolet.

The best way to eliminate a lot--maybe all--of the unwanted bullet swaging is to seat bullets and taper crimp in seperate die steps. The taper-crimp seater dies are still seating bullets while the taper crimp is being placed, and this will cause both swage-down and uneven overall lengths. One attribute of the revolver bullet's crimp groove or cannelure is that the case mouth being roll-crimped does not normally bite into the bullet sidewall significantly.

Another cause of swage-down is an expander spud of insufficient size. E.G., the spud for the 9mm die set measures .352", which is OK for jacketed .355" bullets--but will jack up castings sized @ .357". An expander spud (or ball) of .002"-.0025" smaller diameter is all that is required to hold cast bullets in place, and will prevent swage-down with all but the softest alloys. Just flaring won't prevent swage-down if the expander spud/ball is undersized for the application.