Roll crimp for moon clips?

[pskys2]

On 3/5/2019 at 2:13 PM, swordfish said:

Just checked some 929 rounds today, there is a .020" jump in length with rounds scavenged from partially fired moons. Shot some 6 shot arrays at the last match and loaded the unused rounds in new moons for practice tonight. One decided to stick in the checker, which is weird because they've all been gauged before and passed. So I got out the calipers.

Using Blue Bullets, so no cannalure. Didn't measure the taper crimp, but it's pretty deep to allow for easy loading. I think the longer OALs can be affecting power factor sometimes, which would account for one or two performances of scraping the floor at 125.4pf. Now I load all my stuff to 135pf but I can only imagine accuracy might be inconsistent with the different velocities, if there is indeed a difference (I would assume so since I've tested different length OALs with a similar load out of an automatic). I'm having not the best of luck with 50yard groups, handheld. In my auto they're much nicer.

 

So what is my next step? Is the roll crimp die a completely separate thing, or do you just crank the taper crimp die down until it starts to roll in on itself?

I noticed bullet pull even using a Roll Crimp on my 44 russians with 240 lrn at 710 f/s I used for USPSA Revolver competition.  I've noticed significant pull with 38 short colts with plated bullets and either roll or taper crimps.  I've never noticed any significant loss of velocity or accuracy when after the match I'd reuse the rounds in separate moon clips for practice afterwards.  

Right now I'm using 160 Bayou's at 810 f/s with a .370 taper crimp and I don't see much creep at all.  

By using a real deep taper or roll crimp without a crimping groove can pierce the poly coating or plating of a bullet.  I've had a plated bullet separate in a match with a 45 but even though it sounded funny and the base made a 3rd hole it luckily didn't hurt the gun.

I've tried the 38 short colt Lee Roll Crimp and didn't think it helped and didn't like the fact that I kept rolling the crimp down until the case bulged and caused issues with fitting into the cylinder.  But maybe you'll have more luck.

[swordfish]

On 3/6/2019 at 12:06 AM, mchapman said:

Chris , Lee has a 38 short colt die set that has a roll crimp die. I use that for my short colts and my 9mm for my 929, not a heavy roll crimp just a slight one and it works for both with no adjustment.

ok I might try that.

 

Anyone have any experience with the Lee FCD for 9mm? I really like my deep taper crimp, and I know on the .223 it pinches on 4 sides but leaves 4 spots between the collet that stick out and I don't want those to hang up.

I guess I could just chrono the 1.170OALs to see if there's any significant difference in accuracy or velocity.

[ffl]

I use the Lee FCD on 9mm and 38super.  you want the crimp to be just tight enough to hold the bullet.  if you pull a bullet and it has a ring indented on it you are crimping way too much.

 

I have even used it on 38 short colt with lead bullets.

 

 

[MikeyScuba]

I use the LEE FCD 9mm.  I know guys claim it will swage down a larger bullet but I just re-measured a .358 projectile and it doesn't.  And from my picture below I'm over crimping too but I'm not seeing accuracy issues.

 

And I get zero bullet creep (not surprising really)

 

 

[swordfish]

28 minutes ago, MikeyScuba said:

I use the LEE FCD 9mm.  I know guys claim it will swage down a larger bullet but I just re-measured a .358 projectile and it doesn't.  And from my picture below I'm over crimping too but I'm not seeing accuracy issues.

 

And I get zero bullet creep (not surprising really)

 

 

That looks like mine. I'm using .358 Blue Bullets. They suggest on the website to crimp until a slight impression is visible.

[MikeyScuba]

Ibejheads 165gr.  They sponsor ICORE matches so that's a plus.

[MikeBurgess]

1 hour ago, swordfish said:

ok I might try that.

 

Anyone have any experience with the Lee FCD for 9mm? I really like my deep taper crimp, and I know on the .223 it pinches on 4 sides but leaves 4 spots between the collet that stick out and I don't want those to hang up.

I guess I could just chrono the 1.170OALs to see if there's any significant difference in accuracy or velocity.

for non bottle neck cases its just like any other taper crimp die just with the addition of a size ring.  

 

 

[swordfish]

6 minutes ago, MikeyScuba said:

Ibejheads 165gr.  They sponsor ICORE matches so that's a plus.

I mean the indentation on the bullet, not the bullet itself lol