.40s&w crimp?

Icefire

Icefire

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I just found out at a match that I wasn't crimping my ammo... it was .002 less than the wall but still it wasn't crimped.

I had jam after jam (stovepipe, double feed, failure to go in battery).

How much should I crimp? I just made some test and I wounder which way should I go? I got a CZ75b, Lee pro 1000, 1.135" AOL. I don't want to buy the Factory crimp since I would have to crimp them one by one after.

Left is my ammo before, next is rim just taper enought to remove the belling, next to are roll crimped.

Crimp is : .417 .413 .398 .398, wall is .417

crimp.jpg
 
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The "rim-crimped" one looks about right. Mic 'em and see where they come in. The other 2 are too severely crimped.

FWIW, I run all of mine thru the Lee factory crimp when I'm done. Never had a jam.
 
Icefire said:
I just found out at a match that I wasn't crimping my ammo... it was .002 less than the wall but still it wasn't crimped.

I had jam after jam (stovepipe, double feed, failure to go in battery).

How much should I crimp? I just made some test and I wounder which way should I go? I got a CZ75b, Lee pro 1000, 1.135" AOL. I don't want to buy the Factory crimp since I would have to crimp them one by one after.

Left is my ammo before, next is rim just taper enought to remove the belling, next to are roll crimped.

Crimp is : .417 .413 .398 .398, wall is .417
Click to expand...

I know you know what you're doing, but man don't even think about running those last two... I'm surprised your press would do that... they're almost starting to look like .357SIG...

I've got the Lyman 47th here... nominal case diameter at the base is .424" and at the mouth after seating is spec'd at .423"... so (obviously) that's a one thou crimp... and they actually say here about the .40S&W

"A modest taper crimp may be employeed if found necessary..."

C.O.L is spec'd max at 1.135" so you're there, but having said that, all of the loads they list for 180Gr FMJ are spec'd at 1.115"... I'd bet that the C.O.L. is a more likely culprit for the FTF type issues etc... unless the case mouth is still belled slightly, then I guess it might "snag" along the feed path somewhere, but you'd see that... are the mags your using "tested"...? In my experience, crimp problems most often result in issues like big deltas in speed (ES's), tumbling, bad accuracy...

fwiw,

Dave.
 
kenjuudo said:
I know you know what you're doing, but man don't even think about running those last two... I'm surprised your press would do that... they're almost starting to look like .357SIG...

I've got the Lyman 47th here... nominal case diameter at the base is .424" and at the mouth after seating is spec'd at .423"... so (obviously) that's a one thou crimp... and they actually say here about the .40S&W

"A modest taper crimp may be employeed if found necessary..."

C.O.L is spec'd max at 1.135" so you're there, but having said that, all of the loads they list for 180Gr FMJ are spec'd at 1.115"... I'd bet that the C.O.L. is a more likely culprit for the FTF type issues etc... unless the case mouth is still belled slightly, then I guess it might "snag" along the feed path somewhere, but you'd see that... are the mags your using "tested"...? In my experience, crimp problems most often result in issues like big deltas in speed (ES's), tumbling, bad accuracy...

fwiw,

Dave.
Click to expand...

Have to agree with Dave here, most of the malfunctions you describe aren't crimp related. Failure to go into battery yes, every thing else, not likely. Sounds more like your overall length is out. Some guns are very picky, I'd start there.

Oh, where the last two bullets in the picture bad to you some how? You sure punished them:D (Don't shoot those two, pull em down and toss em)
 
mmmmmmm..... what a way to test a new load.... during a match??? That's a big NO NO!! (I am sorry but I cant help it) :p

Hint:
You did not mention if this is a new gun or a new barrel or a gun that use to feed properly using a factory round.
Stovepiping and double feeding is kinda unrelated to the crimp of your rounds.... sounds more of a feed ramp or extractor or even a magazine feed lip related issue.
How smooth is your feed ramp?
Have you check-clean the extractor lately? :)

Anyways, the second from the left is all the crimp you need. Keep your crimp that way & try longer OAL of 1.150.

Let us know how it goes.. keep us posted.:)

Good luck. Reload safely.
 
I have never had to crimp for my .40S&W, Just enough to close the bell on my lead reloads. And no, I have never had bullet setback, even after feeding the same round 10 times, no measurable setback.

I would like to know where you got those round nose bullets?, and maby try some swc or something similar.

How tight is the one in the far left in your chamber? I would consider the second from the left over crimped, as it looks like its causeing a bulge in the brass. Case tension should be enough to hold the bullet.
 
nognog said:
mmmmmmm..... what a way to test a new load.... during a match??? That's a big NO NO!! (I am sorry but I cant help it) :p

Hint:

Stovepiping and double feeding is kinda unrelated to the crimp of your rounds.... sounds more of a feed ramp or extractor or even a magazine feed lip related issue.
Good luck. Reload safely.
Click to expand...

It is IF the OAL is getting shorter.
 
Those RN are Excel but I got from someone here in a deal.

I shoot SWC lead normaly with no problem but matchs ask for NO LEAD.

Factory ammo I tested was 1.135" swc.

The LEE die allow to do those crimp since they do both taper/roll crimp.

All my resized brass are .417, not .423.

With no crimp I have no set back.

I got 5 like-new used mags, the lips might be too open, I'll look at that
 
This may sound silly, but have you measured the bullet diameter?

The reason I ask is 1) I haven't seen any round nose bullets in .40, and 2) the crimp seams very deep to me. Something looks fishy to me.

Anyhow, I agree with 2nd from the left looks about right.
 
Lee Precision said:
Dummy cartridge #2 would be the correct crimp (counting from the left). The two on the right look like the bullet seating die is adjusted too far down, and the case mouth is actually passing through the crimp shoulder, while the one on the far left has no crimp at all.
Click to expand...

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