Hello guys, this is my first post. Just got my m&p 10. I havent fired it yet. I just got some new magpul mags and was just testing function. Like the title says, my m&p 10 is closing the bolt forward automatically during bolt-lock reload. Pretty much the same as my m&p 9 pistol. I called SW CS and the rep told me its completely normal and is functioning like its supposed to. My m&p 15 DOES NOT do this. No matter how hard i slam a mag in the 15, it doesnt close the bolt. The 10 however does it with not that much force. Im very aware of the debate about the auto-forward "feature/issue" with m&p pistols and my m&p9 does this without much force when seating the mag. Also has been 100% in reliably picking up the first round **knock on lots of wood**. My new m&p 10, however, will pick up the first round consistently if i do a solid reload without binding the mag in the magwell, but if i bind the mag in magwell trying the get it up there, it will sometimes close the bolt prematurely and not strip the first round. Also noticed that the more fully loaded the mag is, the easier it is for it to close bolt automatically, whereas if i only load 1 round in the mag, it takes some smacking on the mag for it to close the bolt on its own. Anyone else experience this?

Edit:
I also noticed on my m&p15 that the bolt catch holds onto more surface area on the bolt face than the m&p10. M&p15 = covers the 2 bolt lugs almost completely. M&p10 = Barely holding onto bolt lug (if giving bolt lug length a value of "10"..bolt catch only covers a value of "1.5".
M&p10 also does this with the 10rnd steel mag, same as magpul mags......fully loaded=not much force needed, 1-2rnds in mag=much more force needed.

Ok...so i did a little more looking into it today and i really do believe this problem has something to do with the bolt catch barely holding onto the bolt lug, thus a minimal amount inertia created by inserting the mag will cause it to release on its own. Again my m&p15 bolt catch holds onto 2 bolt lugs and covers them almost completely whereas, the m&p10 only holds onto 1 bolt lug and BARELY at that. I tried to search this problem on google and absolutely nothing comes back with this problem on any AR style platform. Only for the m&p pistols which is a known issue. I tried to check as many youtube videos of dudes running the m&p10 dry and reloading during bolt-lock and i havent seen this problem arise in their videos. I even saw nutnfancy during his m&p10 run n gun where he inserted a new mag during bolt-lock and even hit the magazine on the bottom to make sure its seated and still the bolt stayed in place.

Again i called sw customer service and they told me its normal.

Binding the mag in the magwell while reloading (ie sh***y reload) will cause the bolt to prematurely slam forward before the mag is inserted fully.

Can anyone check their m&p10s to see if their bolt catch is holding onto 1 bolt lug and barely at that? Im stumped right now.

Mine is holding quite solidly on both lower lugs.


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Thanks sgtsandman....Well that pretty much confirms that the bolt catch is the problem. I tried for s**ts and giggles to just shake the rifle while the bolt was locked to the rear and it doesnt take much for the bolt to slam forward. I took it to a certified sw armorer around my area and he also said something might be impeding the movement of the bolt catch from achieving the proper angle, most likely on the ambi side of the bolt catch bc there's theoretically nothing to impede the bolt catch from going all the way up on the standard side (standard bolt catch side rh shooter). It doesnt go all the way up on my gun.

You are welcome. Have you broken the rifle down so you can visually inspect the lower for an obvious obstruction of part problem?


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Not to the point of removing the bolt catch, but yes we (armorer and i) broke the it down to make sure there is nothing else that is impeding movement. It just seems that the bolt catch itself isnt moving all the way up, but the only way to confirm is to remove the bolt catch. Im taking it back today so he can work on it while im there (otherwise he wouldve had to do paperwork for me to leave the rifle there).

So a little update...removed both the ambi and standard bolt catch and found that there is a detent and spring where the standard bolt catch rides on. Removing just the ambi-catch didn't change anything. So it looks like when the gun was manufactured, the wrong sized detent was installed. Theres nothing else that would impede movement. The only other possibility is that the hole the detent rides in is too shallow which seems unlikely but who knows, maybe they missed it during manufacturing. Going to call S&w monday to see if they will send the correct sized detent.

Can you post some pics?

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Sorry, I just sent the rifle back to s&w yesterday morning. It looks like the detent/plunger is the correct size. We even changed the bolt catch to a standard ar15 one and still had the same problem. It just doesnt get enough angle to sufficiently engage the bolt catch. Just picture your bolt catch only holding onto 1 bolt lug barely by the edge whereas every ar15 we checked engages 2 bolt lugs almost completely. Both the ar15's and m&p10's bolt catch's bottom out on the receiver (meaning the plunger doesnt bottom out but instead the bolt catch hits the receiver before the plunger can be fully depressed). The difference being the ar15 gets enough angle to engage 2 bolt lugs before bottoming out on the receiver whereas the m&p10 only engages 1 bolt lug literally by the edge before it also bottoms out on the receiver. I can also tell the ar15 bolt catch sticks out a little further than the m&p10 with the hinge (where roll pin holds onto bolt catch) being slighty taller. The m&p10 hinge is closer to the receiver which i believe is causing it to not get enough angle. The other option being the hole in the bolt catch itself where the roll pin goes thru (the hinge section) is in such a spot that it doesnt allow it to have full movement.

Best way i can describe it is to picture a see-saw and pretend its a bolt catch/release (bolt release paddle on one end of the see-saw and bolt catch on the other). The closer the center of the see-saw (where it hinges) is to the ground, the less movement the see-saw has. If the center of the see-saw was more elevated, the more movement it would have.

That is pretty much what is going on.

So either the hinge doesnt bring out the bolt catch far enough away from the receiver in order to give it the proper angle, which would be a manufacturing defect since that hinge is part of the receiver.....or.....the hole in the bolt catch assembly that connects it to the hinge with the roll pin, is in the wrong spot.

The following is a picture of my regular ar15's bolt catch and what it SHOULD look like.
See how it holds onto 2 bolt lugs almost completely....
image.jpg

Picture my m&p10 barely holding onto 1 bolt lug just by the edge of the bolt lug.

I probably have 30 firearms new and used. I'd say more than half close automatically

If its a by-product of a certain design like the m&p pistols and it does it consistently and picks up that first round consistently, ill live with it...but in my case, its not consistent. If i fudge the reload and bind the magazine in the magwell while inserting it up there with some force, it will close prematurely w/o stripping the first round.

I am not a fan of the whole "auto-forward" thing. Even on my m&p 9...it still makes me hesitate during the reload. I still have the habit of trying to manually put it in battery even tho it automatically does it. And im still a little skeptical that it will work every time, all of the time. Mine, so far *knock on wood*, has worked all the time with the specific ammo that i use. I had 1 failure to feed using hornady hollow-points but otherwise it works.

I don't have as many, but the percentage is about the same. Used to be a real issue when I shot high power. The rifle would load itself before the command was given.

Got a call back from sw....they're replacing the rifle. Although they didnt tell me the specific reason (nor did i ask), them replacing the rifle has to confirm that it was the hinge.