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LeGendre Crimp reference collection

PostPosted: Tue Dec 04, 2012 3:40 pm
by Colohunter
I've been looking through some of the old reloading threads to find information about using the LeGendre crimp, aka "stab crimp,""side crimp," etc. I noticed that a lot of the information has been spread out over the last couple years and several threads. I figured that since I found several good threads I would post links to the individual threads to help others with locating the information. If I missed any good threads feel free to add them below.

Hoot’s stab crimp revalations:
Discuss the advantages of the stab crimp and the fact that Hoot was able to obtain high velocity and more consistent ignition.
http://450bushmaster.net/viewtopic.php?f=5&t=12928&hilit=stab+crimp

Best Loads:
Discussion on loading up 200gr FTX bullets and the presence of sooting related to the stab crimp:
http://450bushmaster.net/viewtopic.php?f=5&t=12913&hilit=stab+crimp

Case annealing:
Hoot’s experience with annealing cases. Includes information about how he does it and the results he noticed:
http://450bushmaster.net/viewtopic.php?f=5&t=12871&p=35837&hilit=stab+crimp#p35837

Magtech 230gr Load:
Sheepdawg’s experiments with the Magtech 230gr FMJ bullet. A lot of discussion about crimp, pressure and velocities:
http://450bushmaster.net/viewtopic.php?f=5&t=8633

Re: LeGendre Crimp reference collection

PostPosted: Wed Dec 05, 2012 12:22 am
by Texas Sheepdawg
Thanx! I'm going to sticky this.

Re: LeGendre Crimp reference collection

PostPosted: Wed Dec 05, 2012 3:11 pm
by jerdebson
Once again our members show their worth to the community. Thanks for your efforts it will help when we're digging around for an answer. Thanks.

Re: LeGendre Crimp reference collection

PostPosted: Wed Dec 05, 2012 7:18 pm
by wildcatter
Now, if we can get the Gunny to shime in, we'll find out, how much he likes the LeGendre Side Crimp and how he is using it, to achieve results, wherein he has a hard time getting the bullet, out of the case, after crimping.

I think you'll find that he attributes his phenomenal 450LM results to that crimp..

..t

Re: LeGendre Crimp reference collection

PostPosted: Wed Dec 05, 2012 11:12 pm
by pitted bore
As far as I know, this post on the old 450B thread on the calguns.net forum is the birth announcement of the modified Lee Factory Crimp Die:

Post for 18 October 2008

--Bob

Re: LeGendre Crimp reference collection

PostPosted: Thu Dec 06, 2012 10:22 am
by wildcatter
pitted bore wrote:As far as I know, this post on the old 450B thread on the calguns.net forum is the birth announcement of the modified Lee Factory Crimp Die:

Post for 18 October 2008

--Bob


Yup, it is Bob, I was a little vague, because it was such a radicle departure from the norm and I didn't want to get my head bit off. But to my surprise, it was well received and in wide use today..

..t

Re: LeGendre Crimp reference collection

PostPosted: Sat Dec 08, 2012 12:40 am
by gunnut
wildcatter wrote:Now, if we can get the Gunny to shime in, we'll find out, how much he likes the LeGendre Side Crimp and how he is using it, to achieve results, wherein he has a hard time getting the bullet, out of the case, after crimping.

I think you'll find that he attributes his phenomenal 450LM results to that crimp..

..t

If you cut the collet right, You can side crimp into the canalure on some bullets with ease and not distort the bullet at all. It will take 6 to 8 hard wacks with a bullet puller to get it out! This eliminates all bullet pull when chambering and gets things cookin for at least 100FPS faster! No canlure, no problem. Just stay about .20 off the heal of the bullet for same results. follow them up with a tapper crimp just to dress up the case mouth.
I use this for all 450 LM development! With the right bullet & load this method has reduced my extreme spread to 8 FPS!
This also eliminates any bullet pull while IN the Magazine. Which causes feed and chambering problems.
My .02 worth. ;)

Re: LeGendre Crimp reference collection

PostPosted: Wed Feb 18, 2015 7:44 pm
by Dave selepack
I am new to forum, but you guys are awesome, waiting for my new upper , comes in march just got my dies and cases today. Can't wait thanks for all the info

Re: LeGendre Crimp reference collection

PostPosted: Thu Sep 17, 2015 3:10 pm
by m113103
Has anyone tried to modify the LCD to tri crimp like I have seen on some factory loads? When crimped it leaves a gap between the collets so you can headspace off the mouth of the case. :D :P

Re: LeGendre Crimp reference collection

PostPosted: Thu Sep 17, 2015 10:07 pm
by Hoot
This should go in the try at your own risk category.

Several years back, on a whim, I took an empty case that was in the cull bucket and using the taper crimp die dialed further and further down to see where the case would no longer positively headspace. I stopped at .460 and it was still stopping on the chamber lip every try. The thread is somewhere here, buried in noise. Now I personally would not crimp the mouth down that far in an active load, as that would compromise the bullets shape too much and yes there is such a thing as too much neck tension. Tried that also with some 200 XPB bullets utilizing two stab crimps, one in each of the driving band grooves. I would characterize the experience as more of a controlled explosion than ignition. Came away OK, but the 200 XPB's were clocking the traps at 2700 fps using a load that typically produced 2400 fps using Lil Gun! Turned heads up and down the firing line when I touched the first one off. I suppose you could experiment with reducing your loads or using a slower powder, but that's uncharted territory.

The point being, you can crimp the mouth diameter a lot further down than the Hornady recommended minimum of .474 or thereabouts, and not risk failing to headspace on the mouth. As for setting up an FCD to crimp right at the mouth, my experience has been that there is a tendency for the wall thickness to thin if you squeeze it a lot right at the mouth since it is only supported on one side of the transition as opposed to further down the case. You can not re-thicken thinned mouths. More in the cull bucket... :roll:

I have seen the effect of the gap in the collet fingers leaving distinct transition marks, but not strong enough to consider relying upon those three small ridges for a safe headspace. You're better off doing as WC recommends and creating a narrow bite line width for transferring the best, sharp, bite through the harder brass and into the softer bullet. If you do not thin the bite, the crimp is distributed too far over a range of wall and you wind up with a gradual hour glass transition. Bad for accuracy and bad for neck tension. The only caveat with the bite line width is you don't want it so sharp as to create a "tubing cutter" deep skive in the cases or risk them separating along that line. That one I haven't tested the limits of. I have already used up my 9 lives, thank you kindly ;)

Taper crimping down in the cannelure groove or driving band groove provides adequate neck tension to satisfy the most picky accuracy buff and the loads are just as lethal at 2400 fps as 2600. The only plus side to striving for maximum safe velocity is a slight improvement in the maximum range that the XPBs will actually open up. There is the added benefit of less barrel jump which ultimately slows down has fast you can reacquire the target. The 200 XPB loads I use for whitetails is tame by some standards, but they're a pleasure to shoot and recover from, not to mention the distance I encounter whitetails at, in the Northern Minnesota woods, don't require long flat trajectories.

Hoot