ProGunGuy Posted April 12, 2013 Share Posted April 12, 2013 I measure my crimp at .377/378 consistantly. I keep reading people crimp at .368-.373 many times. So what is the correct crimp for 9mm? Link to comment Share on other sites More sharing options...
sandrooney Posted April 12, 2013 Share Posted April 12, 2013 I crimp to .377/.378 and it seems to work well for me. Link to comment Share on other sites More sharing options...
yoshidaex Posted April 12, 2013 Share Posted April 12, 2013 Depending on brand of brass, I get between .375-.379 Smaller and I start seeing marks on bullets (I pull bullets that don't pass QA) Link to comment Share on other sites More sharing options...
Trident Posted April 12, 2013 Share Posted April 12, 2013 I shoot for .376 Link to comment Share on other sites More sharing options...
ltdmstr Posted April 12, 2013 Share Posted April 12, 2013 9x19 is supposed to have a taper crimp, not a roll crimp. Taper crimp is intended to facilitate feeding, not to hold the bullet in place. Should be a couple of thousandths at most. More is not better. Link to comment Share on other sites More sharing options...
Chronodude Posted April 12, 2013 Share Posted April 12, 2013 Crimp enough so that the bullet doesn't push back into the case when you push it against your reloading bench edge. Link to comment Share on other sites More sharing options...
ltdmstr Posted April 12, 2013 Share Posted April 12, 2013 Crimp enough so that the bullet doesn't push back into the case when you push it against your reloading bench edge. This is not correct. The crimp is not supposed to hold the bullet in place. It is supposed to be held in place by an interference fit with the case. If you are relying on the crimp to hold the bullet in place, you need to get a smaller (i.d.) sizing die. Link to comment Share on other sites More sharing options...
DougCarden Posted April 12, 2013 Share Posted April 12, 2013 Crimp until your finger can smoothly go over the case mouth. If there is a rough edge it will get hit by the rim of the case coming out of the chamber and stop, pulling off the extractor. That is all you need... DougC Link to comment Share on other sites More sharing options...
Powerslide91 Posted April 13, 2013 Share Posted April 13, 2013 Just for more data, I have found that measured of 0.377 seems to work well in my pistols for the pickup brass I use (Win, R*P and Speer mainly). I tried to run the least amount of crimp and get it to feed well. Larger than 377 and I have had some issues, at least on a Springfield XD. I have noticed on my reloads the bullet will setback a few thousandths each time I chamber a round. I see the comments about crimp not retaining the bullet, but I have wondered if I need to try slightly more crimp... Link to comment Share on other sites More sharing options...
Sarge Posted April 13, 2013 Share Posted April 13, 2013 I have noticed on my reloads the bullet will setback a few thousandths each time I chamber a round. I see the comments about crimp not retaining the bullet, but I have wondered if I need to try slightly more crimp... NO! More crimp can actually lessen the neck tension on a bullet. The only thing that assured me no setback was going to the Udie. Link to comment Share on other sites More sharing options...
j0s3ph Posted April 13, 2013 Share Posted April 13, 2013 So is I take it that none of you use Lee Factory Crimp Die because it doesn't give you a taper crimp? What is a good crimping die? Link to comment Share on other sites More sharing options...
ltdmstr Posted April 13, 2013 Share Posted April 13, 2013 (edited) As stated above, a taper crimp is intended to facilitate feeding. It is basically just to remove the flare from the case mouth. That's it. The proper way to check your die is to get a ball gage and micrometer and measure the i.d. of your sized case. That should be at least .002 smaller than the o.d. of the bullet you're using. That's the only way you can assure against bullet setback. If you crimp the thing enough to accomplish this, it's going to be to the point that it has a negative effect on accuracy. Edited April 13, 2013 by ltdmstr Link to comment Share on other sites More sharing options...
G30SF Posted April 13, 2013 Share Posted April 13, 2013 I have found not enough crimp it don't feed properly. Too much crimp will kill accuracy. The type of bullet, you will have more or less crimp. For example plated bullets I crimp to .375 and FMJ .371. The plated is softer material and the brass gouges the bullet if crimped to hard. Where FMJ can take more crimp without gouging. Then it can also be gun specific to which like what crimp. Last week I was trying some loads, all the same crimp and load. My Glock 17 loved them, my 26 hated the same load. The groups you would not have believed they were the same load. Link to comment Share on other sites More sharing options...
Justsomeguy Posted April 13, 2013 Share Posted April 13, 2013 As several others have stated, the crimp will NOT keep the bullet from setback. A properly sized case is the only way to assure you will not have setback. The crimp, although relative to bullet diameter, is also dependent on the average thickness of your cases. Measuring a random sample of your cases and doubling the case wall thickness and adding that to bullet diameter gives the MINIMUM taper crimp at the case mouth. You should add about .001-.002 more crimp to insure good feeding and not have the base of the extracting case hang up on the mouth of the next round in the magazine while extracting. Thus, after crimping properly, running a finger over the bullet and case mouth interface should feel rather smooth and not too sharp. Link to comment Share on other sites More sharing options...
gng4life Posted April 13, 2013 Share Posted April 13, 2013 This keeps it simple...set your crimp between .376-.378 and you will be fine, with all types of bullets. Link to comment Share on other sites More sharing options...
Jaxshooter Posted April 13, 2013 Share Posted April 13, 2013 I use a Lee FCD for all my 9 mm, 40 S&W, 45 ACP major loads and on my 38 Super ICORE loads. All are very accurate loads. Link to comment Share on other sites More sharing options...
polizei1 Posted April 13, 2013 Share Posted April 13, 2013 (edited) I use a FCD. Anything between .376-.380 will generally be fine, but again that depends on your sizing and crimp die. Edited April 13, 2013 by polizei1 Link to comment Share on other sites More sharing options...
cecil Posted April 13, 2013 Share Posted April 13, 2013 Crimp until your finger can smoothly go over the case mouth. If there is a rough edge it will get hit by the rim of the case coming out of the chamber and stop, pulling off the extractor. That is all you need... DougC thats how i do it.. Link to comment Share on other sites More sharing options...
sroe3 Posted April 14, 2013 Share Posted April 14, 2013 .378 all the time. Link to comment Share on other sites More sharing options...
Koppi Posted April 14, 2013 Share Posted April 14, 2013 I'm with Doug on the crimping question So, can we all agree that we don't need any more gun control? :-) Link to comment Share on other sites More sharing options...
rfwobbly Posted April 14, 2013 Share Posted April 14, 2013 I measure my crimp at .377/378 consistantly. I keep reading people crimp at .368-.373 many times. So what is the correct crimp for 9mm? There is NOT a single number, and therefore there are numerous opinions to take its place. Taper crimp simply erases the belling (or "flare"). If you agree with that statement, then you must also agree that the perfect TC diameter is simply the bullet diameter + 2 case wall thicknesses. Bullet diameters and case wall thicknesses vary from brand to brand which is why a single number cannot be published. To derive your TC diameter you can physically measure those numbers, or you can simply seat a new bullet into the mouth of a sized, but un-flared, case. Since the TC is there to erase the flare, it stands to reason that if the flare was never there, then the resulting diameter must be the answer. This test generally results in a diameter from .375 to .379". If your bullet is pushing back in the case, then you need to polish the diameter of your expander down by .001" and try again. Link to comment Share on other sites More sharing options...
ltdmstr Posted April 15, 2013 Share Posted April 15, 2013 I measure my crimp at .377/378 consistantly. I keep reading people crimp at .368-.373 many times. So what is the correct crimp for 9mm? There is NOT a single number, and therefore there are numerous opinions to take its place. Taper crimp simply erases the belling (or "flare"). If you agree with that statement, then you must also agree that the perfect TC diameter is simply the bullet diameter + 2 case wall thicknesses. Bullet diameters and case wall thicknesses vary from brand to brand which is why a single number cannot be published. To derive your TC diameter you can physically measure those numbers, or you can simply seat a new bullet into the mouth of a sized, but un-flared, case. Since the TC is there to erase the flare, it stands to reason that if the flare was never there, then the resulting diameter must be the answer. This test generally results in a diameter from .375 to .379". If your bullet is pushing back in the case, then you need to polish the diameter of your expander down by .001" and try again. Agree with most of that, but who uses an expander for a pistol cartridge? The way to correct it is with a smaller i.d. sizing die. Link to comment Share on other sites More sharing options...
Sarge Posted April 15, 2013 Share Posted April 15, 2013 I measure my crimp at .377/378 consistantly. I keep reading people crimp at .368-.373 many times. So what is the correct crimp for 9mm? There is NOT a single number, and therefore there are numerous opinions to take its place. Taper crimp simply erases the belling (or "flare"). If you agree with that statement, then you must also agree that the perfect TC diameter is simply the bullet diameter + 2 case wall thicknesses. Bullet diameters and case wall thicknesses vary from brand to brand which is why a single number cannot be published. To derive your TC diameter you can physically measure those numbers, or you can simply seat a new bullet into the mouth of a sized, but un-flared, case. Since the TC is there to erase the flare, it stands to reason that if the flare was never there, then the resulting diameter must be the answer. This test generally results in a diameter from .375 to .379". If your bullet is pushing back in the case, then you need to polish the diameter of your expander down by .001" and try again. Agree with most of that, but who uses an expander for a pistol cartridge? The way to correct it is with a smaller i.d. sizing die. The powder funnel on Dillon machines(other than the 1050) is an expander as well. I agree though that shrinking the expander does not do much to fight setback. Before I got my bullet feeder which uses it's own funnel/expander I had whittled my original down to where it barely expanded a 9mm case and I still had setback when using FC cases. Like you say, the Udie is the fix. Link to comment Share on other sites More sharing options...
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