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Turbinator
06-16-2005, 3:12 PM
Folks,

Just curious, for you reloaders who do revolver type cartridges, do you generally crimp your reloads?

I was doing up some .357 mag last night, and was loading empty cases to test OAL, etc. I found that pulling the bullets with a kinetic puller was like pulling teeth out of a live boar!! They were stuck like you wouldn't believe, and after about 100 whacks with the puller on a block of wood (which eventually split in two), I could get the bullet out.

After seeing this going on, I was figuring that I wouldn't really need to crimp the bullets in place, and that if I did, I'd just be unnecessarily adding to pressures inside the case. Therefore, I am thinking of not crimping - just enough to remove the case belling but that's it.

Thoughts?

Turby

MPMillen
06-16-2005, 4:26 PM
For many loads a proper crimp is necessary to get proper and consistent burn of the powder.

No crimp will probably lead to erratic and inaccurate ammunition.

Mark

ivanimal
06-16-2005, 4:43 PM
Most wheelguns and any tube fed rifle require a crimp. The last thing you want is to be unable to open your sixgun from too long bullets. This has happened to me with 357 reloads till I bought a Lee factory crimp die. The tube fed problems are ultimately more severe. I use a piece of railroad track, for the kinetic puller to land on, and it takes only one whack. I crimp all but my hunting stuff.

bwiese
06-16-2005, 4:54 PM
I'd be worried that uncrimped loads could on occasion lead to bullet set-back, which could REALLY ramp up pressures.

I know this was a prob w/40S&W; some PDs were having cops do administrative unloading & loading on shift changes into a big barrel of ammo. Evidently enough movement occurred on some rounds that bullet could be set back maybe 0.050" and this would really ramp up case pressure beyond SAAMI standards. (The 40S&W does run already at high pressure to start out with.)

So anyway, I'd go w/crimp.

Bill Wiese
San Jose

-hanko
06-16-2005, 6:15 PM
Go to Redding's website & check out their profile crimp die...I'm loading .357 to their original 1930's velocity, no movement whatsoever.

-hanko

Turbinator
06-16-2005, 8:32 PM
Ok guys - I appreciate the comments - but I need to make it very clear, that when I seat the 158gr bullets in the case, these things are REALLY REALLY stuck in there - no crimp needed to get this effect. I'm not quite sure why - maybe the bullets are slightly oversized, but 1 whack with the puller definitely doesn't get them out of the case.

In the past I've crimped - but this time I feel like if I do, it's going to raise pressures dangerously.. then again, what do I know??

One thing for sure, I don't think I'm going to see any bullets getting inadvertently seated deeper into the cases by mistake - they are just too tight in there.

Turby

-hanko
06-16-2005, 9:57 PM
What's the bullet diameter??

-hanko

Turbinator
06-17-2005, 7:51 AM
Originally posted by -hanko:
What's the bullet diameter??

I'll go home and do 2 things - micrometer the bullet, and try calipers as well.. then report back here.

Turby

ivanimal
06-17-2005, 5:48 PM
That is abnormal do not shoot those till you are sure of the specs on everything. A slight rise in pressure is bad enough. This could be really dangerous.

Turbinator
06-17-2005, 9:14 PM
Ok - call me clueless, but I don't know how to use my micrometer http://calguns.net/groupee_common/emoticons/icon_smile.gif

So here we go with the calipers:

One measured out at .3575"

Another measured out at .358"

Checked 3 more - all a tad over .3575"

A resized case measures out at exactly .357" (inside diameter)

I'm going to guess that these plated bullets are a little oversized. With this possibility in mind, I confirm in my loadbook (Speer #12) that a bullet diameter of .358" does exist - it is a 158gr SWC made of lead and not plated or jacketed. The maker of these projectiles seems to be Hardcast Bullet Co. - "maker of the finest hardcast bullets since 1980" they claim.

More thoughts?

Turby

-hanko
06-17-2005, 9:40 PM
Originally posted by Turbinator:
Ok - call me clueless, but I don't know how to use my micrometer http://calguns.net/groupee_common/emoticons/icon_smile.gif

So here we go with the calipers:

One measured out at .3575"

Another measured out at .358"

Checked 3 more - all a tad over .3575"

A resized case measures out at exactly .357" (inside diameter)

I'm going to guess that these plated bullets are a little oversized. With this possibility in mind, I confirm in my loadbook (Speer #12) that a bullet diameter of .358" does exist - it is a 158gr SWC made of lead and not plated or jacketed. The maker of these projectiles seems to be Hardcast Bullet Co. - "maker of the finest hardcast bullets since 1980" they claim.

More thoughts?

Turby
My thought is 0.001" maximum interference fit is DEFINITELY NOT TIGHT ENOUGH. You also seem to have a pretty high variation in bullet diameters. You're obviously keeping velocity below 900-1000fps to avoid leading the barrel, in spite of the "hardcast" name. You're also making sure that case i.d.'s are uniform, I hope.

A uniform CRIMP is necessary to avoid setback, and the force on the bullets in the gun is greater than you wacking the bullet puller http://calguns.net/groupee_common/emoticons/icon_smile.gif. What happens when a set-back bullet is fired has already been discussed; I wouldn't be surprised if you see serious vertical stringing with uncrimped bullets.

NO reloader I'm aware of would suggest than a revolver bullet NOT be crimped, check out any factory ammo & you'll see what I mean. Stay safe. Get somebody to help you with the micrometer.

-hanko

Turbinator
06-17-2005, 9:55 PM
Thanks, Hanko - so help me out, distilling this down into plain black & white for a moment --

Conclusion #1: There's nothing wrong with the bullet diameters.

Conclusion #2: Whacking 100 times to kinetically pull these bullets is probably normal.

Conclusion #3: Apply an adequate crimp to the cases to prevent bullet setback.

Conclusion #4: This combination of bullets plus crimp probably won't generate excessive pressures.

My comment - there is no leading (or minimal) because these are copper plated.

Thoughts on my conclusions? Am I way out of line here? http://calguns.net/groupee_common/emoticons/icon_smile.gif

Turby

-hanko
06-18-2005, 4:23 PM
Originally posted by Turbinator:
Thanks, Hanko - so help me out, distilling this down into plain black & white for a moment --

Conclusion #1: There's nothing wrong with the bullet diameters.

Not that I can see

Conclusion #2: Whacking 100 times to kinetically pull these bullets is probably normal.

No idea, if I pull bullets I use a collet in the press.

Conclusion #3: Apply an adequate crimp to the cases to prevent bullet setback.

Absolutely

Conclusion #4: This combination of bullets plus crimp probably won't generate excessive pressures.

Bullets for revolvers always need a rolled crimp, over-crimping should not generate as much of a pressure increase as loading the bullet too deeply, or have it move back while in the cylinder. Actually, without knowing your primer, powder type & weight, and loaded overall length I couldn't even guess if you're close to the edge.

Are you loading a bunch of plinkers, or trying to see what you can get out of the round while watching for signs of excessive pressure?? Also, what kind of revolver are you loading for??

My comment - there is no leading (or minimal) because these are copper plated.

Maybe in theory, but I'd keep an eye on the barrel anyway, copper plating is very thin compared to a copper jacket

-hanko

Thoughts on my conclusions? Am I way out of line here? http://calguns.net/groupee_common/emoticons/icon_smile.gif

Turby

Turbinator
06-18-2005, 7:20 PM
Thanks for the tips - the loads are going to be disposed of by using this particular item:

http://usera.imagecave.com/Turbinator/Stuff/IMG_1256b.jpg

I'll probably be using a little bit of W296 - not too much as I know you shouldn't load magnum level loads with plated bullets. I may also use HP38 if it's suitable for .357mag target loads (light loads). I've successfully loaded with W231 in the past with great results for target loads.

As usual, I'm always open to more advice. http://calguns.net/groupee_common/emoticons/icon_smile.gif

Turby

dwtt
06-18-2005, 11:19 PM
I don't have a revolver but I can't see much difference in recoil affecting a bullet in a revolver versus a bullet in an autoloader. I don't crimp my pistol loads and they seem to work fine. Of course, I haven't been looking for setback, but I don't see flattened primers or other signs of excessive pressure. What's the difference in a revolver that requires the loads to be crimped? I do know that my autoloaders headspace from the mouth of the cartridge, so not crimping is a good thing.

-hanko
06-19-2005, 8:43 PM
Originally posted by dwtt:
...I do know that my autoloaders headspace from the mouth of the cartridge, so not crimping is a good thing.
Is your loaded case od within SAAMI specs, especially at the mouth of the case??

-hanko

ivanimal
06-19-2005, 11:25 PM
There are two distinctly different kinds or crimping Roll and Taper I taper crimp all 45 cal bullets. If for nothing else it removes the bell from the resizing die.

dwtt
06-20-2005, 6:58 PM
Originally posted by -hanko:

Is your loaded case od within SAAMI specs, especially at the mouth of the case??

-hanko

My .45 measure 0.473" OD at the mouth. According to the simple drawing in my Lyman's reloading manual, the max OD allowed is 0.476". I don't have the SAAMI spec, but maybe you can tell me if there's somthing wrong with my reloads. Anyway, I still can't see why a revolver cartridge must be crimped while an autoloader cartridge doesn't require crimping.

-hanko
06-20-2005, 8:26 PM
Originally posted by dwtt:
My .45 measure 0.473" OD at the mouth. According to the simple drawing in my Lyman's reloading manual, the max OD allowed is 0.476". I don't have the SAAMI spec, but maybe you can tell me if there's somthing wrong with my reloads. Anyway, I still can't see why a revolver cartridge must be crimped while an autoloader cartridge doesn't require crimping.
Crimping gives uniform case tension over the bullet. Ideally, this helps accuracy by having all bullets leave the case at about the same pressure & velocity.

Autoloading ammo is typically taper crimped, whether by the factory or the reloader.

-hanko

dwtt
06-21-2005, 6:41 PM
Originally posted by -hanko:
Crimping gives uniform case tension over the bullet. Ideally, this helps accuracy by having all bullets leave the case at about the same pressure & velocity.

Autoloading ammo is typically taper crimped, whether by the factory or the reloader.

-hanko

I do crimp rifle bullets for this reason and because the slight differences in velocity and twist at the muzzle are magnified after the rifle bullet has travelled 200 yards or more. But, at the short ranges that pistols are used, I still can't see why revolver bullets need to be crimped. Maybe I just don't get it.

-hanko
06-21-2005, 8:25 PM
Why to Crimp... (http://www.exteriorballistics.com/reloadbasics/crimp.cfm)

-hanko