Factory crimp die for .40S&W
- Thread starter Riven
- Start date
I recently reloaded 800 X 40 S&W with a set of Hornady dies and found that about a third didn't pass inspection with a Lyman 40 S&W Pistol Max Cartridge Gauge.
I bought a Lee Carbide Factory Crimp Die and ran them through that fixing the majority of them.
I bought a Lee Carbide Factory Crimp Die and ran them through that fixing the majority of them.
- Location
- The Orion Arm
A slight taper crimp is all that's needed. Being fired out of a semi-auto, a small crimp is needed in order to prevent bullet set back. YouTube has many videos on this.
Clotho...it sounds like you have a resizing issue rather than a crimping issue.
Clotho...it sounds like you have a resizing issue rather than a crimping issue.
the lee die works very well , in push through mode , on 40 & 45 carts that don't fall in / fall out of the chamber check gauge or are glocked . you don't need it right away , but it's one of those things that is worth the money , & it saves a lot of pulling if your chamber is tight . if you use it in production , it smooths out the coke bottle effect of o/s bullets or u/s dies .
It is a re-sizing issue but it could not be solved with the Hornady sizing die. I tried running the brass through the Hornady sizing die multiple times. I also tried adjusting the seating die again and again etc.
I have reloaded 10's of thousands of rounds on my single stage presses and had never had this problem before. It was fairly minor btw. The rejected rounds still fit the chamber on my CZ 40B. I was just being fussy as I like to use the Lyman Cartridge Gauges on every caliber I can get them for. In the past I have used them for 380acp, 9mm, 45acp and 44magnum with no problem. This time I was getting an abnormal number of rejects.
A friend at a local gun shop suggested I try running them through a Lee Factory Carbide Crimp die as it sizes as well as crimps. I tried that and it solved the problem.
This leads me to the conclusion that the Hornady sizing die is within spec but not as tight in tolerance as the Lee Factory Carbide Crimp die.
I think you nailed it on the head there nada.
I have reloaded 10's of thousands of rounds on my single stage presses and had never had this problem before. It was fairly minor btw. The rejected rounds still fit the chamber on my CZ 40B. I was just being fussy as I like to use the Lyman Cartridge Gauges on every caliber I can get them for. In the past I have used them for 380acp, 9mm, 45acp and 44magnum with no problem. This time I was getting an abnormal number of rejects.
A friend at a local gun shop suggested I try running them through a Lee Factory Carbide Crimp die as it sizes as well as crimps. I tried that and it solved the problem.
This leads me to the conclusion that the Hornady sizing die is within spec but not as tight in tolerance as the Lee Factory Carbide Crimp die.
I think you nailed it on the head there nada.
Lee carbide factory crimp die and .40 Glock
The taper crimp on a pistol primarily reduces the flaring at the case mouth and should NOT be compressed more than .001 to .002. Neck tension holds the bullet in place and the taper crimp just closes the case mouth and adds "slight" tension.
The loads above are Rainier plated bullets and over taper crimping can distort the bullet and destroy accuracy. The Lee factory crimp die has a carbide ring inside the die to reduce any bulge the crimping operation may cause. This carbide ring is larger than the sizing die and normally does not touch the case if sized and crimped properly. The die is popular because competitive shooters use range pickup brass and hate trimming their cases. A long case or thick brass may bulge when taper crimped and the carbide ring in the FCD removes any crimping bulge.
I also use the Lee FCD on my .44 mag with light practice loads that do not require a heavy roll crimp.
Bottom line the Lee Factory crimp die will size any case during crimping and remove any crimping bulge to insure it chambers correctly.
"ANY" taper crimp should be checked with your vernier calipers to insure the case mouth is not over crimped and again should be only .001 to .002 smaller in diameter than the case body.
As a side note the RCBS AR series dies also have a taper crimp and are more forgiving on case length and crimping.
Below the top black .223 die has a taper crimp and the green .223 box below it has a roll crimp.
Below, exaggerated roll crimp and taper crimp shown, the taper crimp image should have the case touching the bullet for its full length and not have an air gap.
The taper crimp on a pistol primarily reduces the flaring at the case mouth and should NOT be compressed more than .001 to .002. Neck tension holds the bullet in place and the taper crimp just closes the case mouth and adds "slight" tension.
The loads above are Rainier plated bullets and over taper crimping can distort the bullet and destroy accuracy. The Lee factory crimp die has a carbide ring inside the die to reduce any bulge the crimping operation may cause. This carbide ring is larger than the sizing die and normally does not touch the case if sized and crimped properly. The die is popular because competitive shooters use range pickup brass and hate trimming their cases. A long case or thick brass may bulge when taper crimped and the carbide ring in the FCD removes any crimping bulge.
I also use the Lee FCD on my .44 mag with light practice loads that do not require a heavy roll crimp.
Bottom line the Lee Factory crimp die will size any case during crimping and remove any crimping bulge to insure it chambers correctly.
"ANY" taper crimp should be checked with your vernier calipers to insure the case mouth is not over crimped and again should be only .001 to .002 smaller in diameter than the case body.
As a side note the RCBS AR series dies also have a taper crimp and are more forgiving on case length and crimping.
Below the top black .223 die has a taper crimp and the green .223 box below it has a roll crimp.
Below, exaggerated roll crimp and taper crimp shown, the taper crimp image should have the case touching the bullet for its full length and not have an air gap.
Last edited:
tictactician
Regular
- Location
- Victoria, B.C.
I have been loading 40 for a while and have had similar issues. I traced it back to a batch of range pick up brass. Try sizing a few cases and see if the drop into your gauge. I found most pieces that failed wherein the bottom of the case near the extractor grove. This was not a crimp problem but bulged brass (sometimes referred to as glocked). Using the lee bulge buster is a better method of removing this before seating the bullet as it avoids overcrowding and undersized the bullet. This is especially true of lead and plated bullets.
