M&P9 Light Hits

[7shooter]

Has anyone had problems with light hits with commercial ammo ( Winchester white box ) with the MP9 ?

 

[7shooter]

Has anyone had problems with light hits with commercial ammo ( Winchester white box ) with the MP9 ?

 

[handgunner356]

I had a earlier M&P40 that the striker did not have a raised pad where the sear catches. All the current guns I checked did have, the catch measured 0.100" front to rear where as the newer one was 0.150". Not much but it would hold slightly more tension on the striker, and hasen't had any more light hits since. Both strikers protruded the pin the same distance through the breechface. S&W couldn't tell me if there was a upgrade, but either there was or this was one that slipped through QC. If it's not short and you are comfortable removing the striker, you can check for a possible buildup of gunk that didn't get cleaned out. The next step would be to call S&W and see if they would either send you a striker or pick up tag to send the gun in.

 

[Fastbolt]

There was a revision to the base of the striker's foot. This 'new' striker has more material added to the front of the striker's 'foot'. This results in more pressure against primer cups because the striker spring is compressed a bit more. This striker revision was discussed in an armorer's class last year.

As with some other striker-fired pistols, any accumulation of sludge, debris, brass shavings, fouling, etc. present in the slide's striker channel, caused by the unwanted presence of CLP, solvents, lubricants, etc., may also adversely affect the forward movement of the striker, lessening its force.

Wouldn't be the first time I've encountered, or observed someone else encounter, a 'hard' or defective primer, though, especially among some of the less expensive ammunition lines. You may sometimes notice that a maker's premium line of handgun ammunition may advertise its use of a 'more sensitive' primer.

Just my thoughts. Why not call S&W customer service and discuss this with someone?

 

[shawn mccarver]

Originally posted by 7shooter:
Has anyone had problems with light hits with commercial ammo ( Winchester white box ) with the MP9 ?

I had a friend who had light hits with his M&P 40, and when it came back from the factory, it was still having the problem. They replaced the barrel and said it was a headspacing or chamber depth problem, which caused the primer to be just a tad further away from the primer which put it right on the edge. That combined with primers a little too hard made for spotty reliability.

Mine from the same era has never malfunctioned, although I sent mince back for the upgrade as well. They were happy to do the upgrade to the barrel and slide.

They were nice enough to send it back with night sights at no charge (not my idea, the tech said they only had slides with night sights at the time). Thus, I got a new barrel and slide with night sights. Great customer service.

Great service.

 

[robmcd]

Remove the striker and be sure that the channel and striker are clean and dry. Oil migrates in through the the firing pin opening in the breech face and around the safety block, especially if you use spray gun cleaning solvents, and light sludge slows the striker. If it still has the problem, call S&W for a return pick-up tag.