M&P 40c

[dannyk45]

I have a M&P 40c and twice with my reloads I have had problems. I"m at work now but off the top of my head I am using WSP primers Win 165 Flat nose with a OAL of 1.12" and 5 grains of Bullseye. I have had a light primer strikes twice in the last 200 rounds and when the weapon does not fire I have to push the slide hard against a hard surface to eject the round, the round fires the second time I chamber it. Hopefully I have explained the issue in detail enough.

 

[eisenhow]

Do all your rounds drop freely into and out of a case gauge?

 

[RickG]

I am not familiar with the OAL for .40 but it sounds as if the round is a bit to long or you are using to much crimp and the brass is bulging just below the crimp.

Either way it sounds as if the round isn't quite allowing the slide to go all the way into battery by a couple of thousands.

 

[dannyk45]

Do all your rounds drop freely into and out of a case gauge?

Never used a case gauge but mic them to make sure there within spec.

 

[eisenhow]

Never used a case gauge but mic them to make sure there within spec.

I'd suggest spending $13 and getting yourself a Dillon case gauge. If you don't want to spend that, I'd at least pull your barrel and try dropping a bunch of them into and out of it.

 

[dannyk45]

I'd suggest spending $13 and getting yourself a Dillon case gauge. If you don't want to spend that, I'd at least pull your barrel and try dropping a bunch of them into and out of it.

I have done that.

 

[Supermoto]

why would you fire a round that did not feed the first time? obviously there was something wrong with it, not only can you risk firing out of battery on some guns, but you also lose the change to see what was wrong with the round

 

[dannyk45]

why would you fire a round that did not feed the first time? obviously there was something wrong with it, not only can you risk firing out of battery on some guns, but you also lose the change to see what was wrong with the round

Good point I won't next time. At the time I just figured the gun was dirty or something.

 

[Supermoto]

Good point I won't next time. At the time I just figured the gun was dirty or something.

Good, now get a case guage

 

[P2A]

It would have to be dirty, like really dirty, likes thousands of rounds without cleaning dirty. Even then its questionable if it would cause the problem.

 

[dannyk45]

I fired it again today to test it out. I saved the rounds that didn't fire and it looks like I did not re size them all the way down to the base. I am going to check my dies and go from there. The cases look like the recoil sized the last part when cycling the round. Thank you for your help everyone.
Dan K

 

[eisenhow]

I fired it again today to test it out. I saved the rounds that didn't fire and it looks like I did not re size them all the way down to the base. I am going to check my dies and go from there. The cases look like the recoil sized the last part when cycling the round. Thank you for your help everyone.
Dan K

Was this range brass or was it once fired from your gun? If it was range brass it was most likely glock bulged. Some people use a EGW U-die (undersized die), others swear by the Lee FCD (factory crimp die). One of they may be your solution after you've triple checked that you have your current dies properly adjusted.

 

[dannyk45]

It looks like almost every 40 case I have are bulged some way worse than others at least 3 thousandths off after resizing.