"Slam Charging" your M&P 9mm

[Merlin Orr]

Well.. A couple of things I do know. The slide release may have been worn but if it was about 115 rounds did the wear on it and...the ramp on the gun I was shooting had a bright mirror polish job by a very gun savy S&W factory shooter.

As a side note .. He is also the greatest revolver shooter who ever picked one up.

[Bigbadaboom]

Well.. A couple of things I do know. The slide release may have been worn but if it was about 115 rounds did the wear on it and...the ramp on the gun I was shooting had a bright mirror polish job by a very gun savy S&W factory shooter.

As a side note .. He is also the greatest revolver shooter who ever picked one up.

I just got back from my range where I experimented with this issue.

Merlin, I think you were suffering 'spring bounce' in the mags. When you slam a partially loaded mag into the gun the force causes the rounds to 'bounce' the spring down like when you pack a mag to get more rounds in it, in turn, causing the rounds to be below the feed lips at the time the slide is returning to battery.

I had never tried to do the 'slam load' with only 10 rounds of factory length ammo before. I load my 9mm Production loads to 1.165" and I guess this helps because I've never been affected by 'spring bounce' until today when I was using Blazer Brass factory ammo (4 out of 10 tries closed on an empty chamber). I also used Win. Ranger SXT factory hollow points and they did catch under the foot of my chamber (or didn't chamber at all 3 out of 10 tries) because when the mag spring collapses during 'spring bounce' there is no upward pressure under the chambering round allowing it to 'nose dive' as it is being cycled into the chamber. I did this same test with the same ammo with the mags loaded to full capacity and, out of about 30 tries, never had a hiccup.

The only time I got a 'nose dived' round in the mag as you experienced was in a mag I that had hit the ground when ejected but I can see it happening during a reload also.

I think that what we need to remember is that these guns were not designed to do a lot of things that we do with them. The mags are not designed to be slammed into the gun partially loaded, the slide release was not designed to hold the slide back under 30-60 lbs. of kinetic force etc. etc..

I guess I should change my previous post to state " I can make any M&P stop doing this or I can make it do this consistently with fully loaded mags"

[Tokarev]

Well.. A couple of things I do know. The slide release may have been worn but if it was about 115 rounds did the wear on it and...the ramp on the gun I was shooting had a bright mirror polish job by a very gun savy S&W factory shooter.

As a side note .. He is also the greatest revolver shooter who ever picked one up.

I just got back from my range where I experimented with this issue.

Merlin, I think you were suffering 'spring bounce' in the mags. When you slam a partially loaded mag into the gun the force causes the rounds to 'bounce' the spring down like when you pack a mag to get more rounds in it, in turn, causing the rounds to be below the feed lips at the time the slide is returning to battery.

I had never tried to do the 'slam load' with only 10 rounds of factory length ammo before. I load my 9mm Production loads to 1.165" and I guess this helps because I've never been affected by 'spring bounce' until today when I was using Blazer Brass factory ammo (4 out of 10 tries closed on an empty chamber). I also used Win. Ranger SXT factory hollow points and they did catch under the foot of my chamber (or didn't chamber at all 3 out of 10 tries) because when the mag spring collapses during 'spring bounce' there is no upward pressure under the chambering round allowing it to 'nose dive' as it is being cycled into the chamber. I did this same test with the same ammo with the mags loaded to full capacity and, out of about 30 tries, never had a hiccup.

The only time I got a 'nose dived' round in the mag as you experienced was in a mag I that had hit the ground when ejected but I can see it happening during a reload also.

I think that what we need to remember is that these guns were not designed to do a lot of things that we do with them. The mags are not designed to be slammed into the gun partially loaded, the slide release was not designed to hold the slide back under 30-60 lbs. of kinetic force etc. etc..

I guess I should change my previous post to state " I can make any M&P stop doing this or I can make it do this consistently with fully loaded mags"

My findings rival yours. I can get a round to chamber by forcefully seating a full magazine and get it chambered with regularity. That's not the case with a 10-rounder.

You're right in that the gun wasn't designed to be used at slide lock with a partial magazine. Why would it be, really? But, if this gun is going to unseat Glock as the King of Production, Smith might want to take measures addressing the slam charge issue.

[fiddler]

Mine did NOT slam charge at the match last Sunday. I think it was because I was trying hard to slow down and get my hits and not worry about speed. (I should have slowed down even more for that %$#@&&& Plate Rack). Guess I wasn't slamming them in like I usually do.

I found it not to be an issue as I was paying attention, and not taking the slam charge for granted. I'm glad though that it was in a match and not a fight.

Roy

[twodownzero]

I did this today, unintentionally, in a match stage. I wasn't sure that a round chambered, so instead of wondering, I racked the slide. At that time, I observed that not only had it fed a round into the chamber, but it also failed to extract that round, and now I had a double feed.

Fortunately, I cleared it quickly, but it totally screwed up my plan on that stage and created a situation that I could have done without.

[jkatz44]

I have a new M&P Pro that I've been playing with. So far I'm really liking it but I've found it does have one annoying feature (or design flaw depending on your point of view).

Now, by "slam charge" I mean getting the slide to drop by forcefully inserting a loaded mag. The gun actually does this without a whole lot of force and I can get the slide to drop with a firm push of the mag into the gun.

Normally this wouldn't be a big deal but I notice that I'll get a nose dive jam when the magazines are loaded with only ten rounds. If I load them up to 17, the slide will drop and chamber a round without problems.

Does anybody else's Pro do this? Is there a way to cure it other than to gingerly seat the mag?

I dont even try to slam charge my mp 9L and it does it every time. the thing is i rarely go to slide lock on a stage so i dont really worry about.

[G-ManBart]

Got a picture tutorial on what area needs to be addressed Mike?

Good idea.

I will; cause I have one I need to deal with. Ill get some pics.

Did you ever take pics of this Mike? My Pro started doing this for the first time today. I played around with it and if I really seated it firmly it would normally strip a round and feed just fine, but if I was a little softer I got a couple that nose dived and required a little tap on the back of the slide to seat. I really don't want it to release by itself and would love to see the way you tweak the slide stop to prevent it. R,

[Nik Habicht]

Or a gamer might see if ten round mags provided the perfect answer --- allowing slam charging while reliably stripping a round.....