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Help With Crimp on 40


jschweg
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I'm a bit befuddled just starting to load for 40 and wanted to get some advice.

 

I'm loading 180gr coated bullets at .401 at a 1.18 OAL. Normally for crimp I simply take 2x a resized case mouth + the bullet which in my case should be .423 and if I crimp to .423 the rounds don't drop into the barrel and get hung up half way. To get the rounds to drop in, I have to crimp down to .421

 

There is a ton of effort to run these down to .421, almost as much as the resizing die and it just feels wrong. When I run 9mm, the crimp die bearly has any effort.

 

Since I have zero experience with 40, is this normal? Is the chamber just too tight to run .401? 

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Well, the SAAMI spec for .40 crimp is .423.  Also, crimping for .40 is the same for pretty much all semi-auto rounds.  Basically, you're just removing the flare on the case, and maybe .001, or at most, .002 more than that.  There's no reason to crimp any more, and at a point, more crimp can potentially cause problems with accuracy.  Also, if the crimp cuts through the bullet coating, you'll get barrel leading.  As for the press, the amount of effort to add an additional .002 crimp should be barely noticeable.  So, something else must be going on.  I would also add, that if the .423 crimped rounds are getting hung up in the barrel, you might want to have someone run a finish reamer through the chamber because that shouldn't be happening.

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I think it's the brass. I've loaded so many 10s of thousands of 9mm that I under estimated how much old glocks screw this 40 brass up.

 

Grabbed some once fired cases that have only been fired from my pistol and they go in with little trouble.

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Just started reloading BBI 180 coated bullets yesterday after loading FMJs for the better part of a decade. Shortage, price increase et all. 
 

Anyway, using a Dillon crimp die, I ran the press up with a loaded round in the station. Screwed the crimp die down till I couldn’t screw it any further. Then in small increments started moving the crimp down down until the loaded round would gauge in my Amanov case gauge, AND plunk test in my barrel. 
 

I agree. At .423 I had to shove the round into the gauge and barrel. But just a touch more, around .422, gauged and dropped into and out of barrel.

 

I’m running these in a CZ TSO. I have to seat them at 1.120”. Started at 1.150”. Had to go all the way down to 1.120” to get them to plunk. Accuracy was superb.

 

I know guys love to run their rounds long, but I encourage you to shorten them up and just see what happens. Almost always (almost) I get better accuracy with shorter COAL. And that’s across all platforms and calibers. For me the only exception is my open gun, when I run them at max magazine length.

 

When I see guys with issues at match’s I’d say 8 outta 10 times their reloaded rounds are too long. Little more. Little less maybe. But it’s more often then not the case. 
 

Good luck.

 

PS. Another issue that you don’t see as much any more, but was especially prevalent in 40 brass is bulged cases towards the bottom from unsupported barrels. Again, not as much of an issue as it used to be due to improvements in barrel designs. But can still be there. If your using once fired bras, try running it through one of the various “bulge busters” out there. I also use the Lee Undersized U die. Helps a lot!

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On 4/17/2021 at 11:58 AM, iflyskyhigh said:

Just started reloading BBI 180 coated bullets yesterday after loading FMJs for the better part of a decade. Shortage, price increase et all. 
 

Anyway, using a Dillon crimp die, I ran the press up with a loaded round in the station. Screwed the crimp die down till I couldn’t screw it any further. Then in small increments started moving the crimp down down until the loaded round would gauge in my Amanov case gauge, AND plunk test in my barrel. 
 

I agree. At .423 I had to shove the round into the gauge and barrel. But just a touch more, around .422, gauged and dropped into and out of barrel.

 

I’m running these in a CZ TSO. I have to seat them at 1.120”. Started at 1.150”. Had to go all the way down to 1.120” to get them to plunk. Accuracy was superb.

 

I know guys love to run their rounds long, but I encourage you to shorten them up and just see what happens. Almost always (almost) I get better accuracy with shorter COAL. And that’s across all platforms and calibers. For me the only exception is my open gun, when I run them at max magazine length.

 

When I see guys with issues at match’s I’d say 8 outta 10 times their reloaded rounds are too long. Little more. Little less maybe. But it’s more often then not the case. 
 

Good luck.

 

PS. Another issue that you don’t see as much any more, but was especially prevalent in 40 brass is bulged cases towards the bottom from unsupported barrels. Again, not as much of an issue as it used to be due to improvements in barrel designs. But can still be there. If your using once fired bras, try running it through one of the various “bulge busters” out there. I also use the Lee Undersized U die. Helps a lot!

 

Long loaded rounds feed more reliably in 2011's.  Not necessary in a CZ.

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