Extended Firing Pin for M&P?

[mizer67]

I'm having issues getting primers to light in my M&Ps. They only run near 100% with Federals. Win SP light off pretty good, and CCIs are the worst with 3-5% FTFs. I've tried switching reloading presses, going from a Hornady LNL to a Dillon XL650, but the problem persists from old press to new press. Extra power striker springs from Speed Shooter Specialties seem to help, but my guns still don't run 100%.

While it's possible it's operator error, my other striker fired pistols run 100% even with CCIs (Glocks / Wather PPQ). I'm running factory springs in two M&Ps and an extra powered striker spring and Apex FSS in another. I'm using factory recoil springs.

Does anyone know of someone that makes an extended firing pin for M&Ps, or of someone that can modify a factory one? Or something else I can look for to completely eliminate light primer hits?

[mcracco]

First of all, have you removed the striker and inspected it and the channel it sits in? Want to be sure the part isn't busted or its travel is impinged by lubricant or other foreign object (head of a q-tip from the last cleaning?).

After all that there is an extra power striker spring available from SSS. And stop calling it a firing pin!

Edited December 22, 2011 by mcracco

[mizer67]

As I mentioned in the OP, I'm already running an extra powered striker spring from SSS in one of my M&Ps, and still get less than 100% ignition.

My newest M&P Pro 5" has ~300 rounds, and has worse issues than my other guns, so it's not the striker channel being dirty, but yes, I clean them regularly and don't use any lube in the channel.

[want2race]

There is something else going on. I've been able ignite the hardest of military primers with the latest striker assembly from S&W. Standard factory striker spring.

Look at the firing pin block safety. Did you contour it, round it over, install lighter spring etc? I read you have the FSS in one gun, what about the other? Untouched stock or APEX sear or has it been filed on?

One of the most important diagnostic things to do is to shoot slow fire and look at the gun before each shot. You need to see the gun BEFORE you have a light strike so obviously this has to be done outside of a match.

Visually inspect each round for high primers. I load up 100 round ammo boxes and look across the bases for high ones.

[mizer67]

Second gun, the 5" pro is untouched stock, it's only a ~month old. It of course has the Pro sear. It runs the worst of the two.

The FSS 4" gun runs better than stock, but it does have the SSS extra power striker spring installed.

I'm sensitive to the high primer issue and visually/physically check all of them prior to shooting.

[Dan Burwell]

While I can do that for you I agree with Shaun there is likely something else going on. Probably ammo related since you are having problems with three different M&Ps. I would recomend chamber checking in your barrels a "lot" of ammo, along with looking carefully at primers. I wouldn't doubt it your rounds are hitting the rifling in the barrels keeping them from fully chambering.

I had some similar problems with precision coated 147s the shoulder on the bullet was such it was easy to get them hitting, had to load really short to get them to 100%

[mizer67]

While I can do that for you I agree with Shaun there is likely something else going on. Probably ammo related since you are having problems with three different M&Ps. I would recomend chamber checking in your barrels a "lot" of ammo, along with looking carefully at primers. I wouldn't doubt it your rounds are hitting the rifling in the barrels keeping them from fully chambering.

I had some similar problems with precision coated 147s the shoulder on the bullet was such it was easy to get them hitting, had to load really short to get them to 100%

I do load fairly long (1.140" OAL with a Montana Gold CMJ). I've done the drop and spin test, and can't tell that these rounds are touching the rifling, but will chamber check a "lot" and see what I find.

Good to know there's another option, however, if I can't find the problem in my ammo.

[HI5-O]

Check to see if your primers are fully seated.

[Dan Burwell]

I do load fairly long (1.140" OAL with a Montana Gold CMJ).

I shoot Montanna Gold 147 CMJs loaded to 1.125. At 1.140 length is probably the problem.

M&P's do not like long loaded ammo.

[sdm74]

While I can do that for you I agree with Shaun there is likely something else going on. Probably ammo related since you are having problems with three different M&Ps. I would recomend chamber checking in your barrels a "lot" of ammo, along with looking carefully at primers. I wouldn't doubt it your rounds are hitting the rifling in the barrels keeping them from fully chambering.

I had some similar problems with precision coated 147s the shoulder on the bullet was such it was easy to get them hitting, had to load really short to get them to 100%

I do load fairly long (1.140" OAL with a Montana Gold CMJ). I've done the drop and spin test, and can't tell that these rounds are touching the rifling, but will chamber check a "lot" and see what I find.

Good to know there's another option, however, if I can't find the problem in my ammo.

That must take alot of powder to make pf

[mizer67]

They're 124 gr CMJ, sorry. 4.2 grains of TG makes 136 PF. I'll try them at 1.125" OAL.

Edited December 22, 2011 by mizer67

[sdm74]

They're 124 gr CMJ, sorry. 4.2 grains of TG makes 136 PF. I'll try them at 1.125" OAL.

Don't forget to reduce your powder when you shorten them

[fastarget]

Check to see if your primers are fully seated.

+1 even if a little,

Also used to have 5% failure to ignite wolf primers, 100% ignition with fed, magtech, winch, reming. Both PRO models had DB's expert trigger work. My wife used the same ammo I loaded for the S-I, at 1.150-1.155 with no issues over 4500 rounds so far.

Can you compare the action and parts, to another M&P?