I've called S&W about my new M&P15 stamped 5.56 Nato on the barrel shooting .223 rounds through it. Problem is, and it occurs often is on empty clip the bolt carrier only locks back sometimes not always. Smith and Wesson told me to try new ammo. So I went out, and bought alot of different brands of ammo, and I still have this problem. has anyone else had this problem?

The dealer I bought it from told me to check it out, and if i see any problems within 30 days if so they will pay to have it shipped back to the manufacturer for repairs? Should I go ahead, and do this? My 30 daytime period is running out. How long usually does this process take, for repairs, and to get the gun back to me?

Have you disassembled, cleaned and lubed it before having shot it? Have you tried a different magazine? Have you tried true 5.56 ammo? It could be short stroking. Have you checked the gas key and/or the gas block to see if they are leaking?

Basic AR Cleaning

My AR is malfunctioning, now what?

Just to make sure I have the correct sequence of events.

1. Shoot .223, fully loaded magazine.

2. No problems.

3. Last round fired, bolt doesn't lock back.

Questions:

A.) What Ammo were you shooting? Brand, projectile weight, etc.

B.) Which model of S&W M&P 15 do you own?

C.) Where do you grip your rifle with your off hand?

D.) Have you installed a Magpul B.A.D. lever or anything else similar?

I have no issues with my 15-Sport.

Separate the upper from the lower. Load one magazine with a snap cap. Leave one magazine empty. Insert each into the lower. Does the bolt stop move the same? Does it move at all?

Is there anything impeding the movement of the bolt stop? Does the bolt stop pivot freely? Wiggle it. Do you feel it binding or dragging in any way?

The bolt stop is dependent on the mag follower. Is there anything preventing the magazine follower from making full contact with the bolt stop.

How many magazines do you own? Are they all the same make/model? To help identify if the intermittent bolt hold open failure is a magazine issue, number your magazines. When the bolt fails to lock back on an empty magazine, make note of which magazine. This will help you to identify a problematic magazine.

Reassemble the lower & upper into a complete rifle. 1 mag empty. 1 magazine loaded with a snap cap (dummy round).

Load the empty magazine. Manually cycle the action by pulling the charging handle back. Does the bolt lock back?

Insert the magazine with the snap cap in it. Chamber the snap cap. Manually cycle the action by pulling the charging handle back. Does the bolt lock back?

That's nice of them. My local LGS only offers that service if you buy his lifetime warranty for $45.

If you want your dealer to take care of it, yes. Your 30 days is almost up.

If you want to wait and take care of it yourself, then go right on ahead. When you call S&W for warranty repair service, they'll most likely send you a pre-paid shipping tag anyways.

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-John

Also... welcome to the forum!

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-John

Do you happen to have a BAD lever on it? Also what magazines are you using? A lot can be told by the accessories you are using.

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Grover Oathkeeper

Have you tried different magazines, and if so does the problem still exist?

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M&P9/9C/Shieldx2/Sportx2/15-22

Try not calling it a "clip" and see if that works?..... I'm just kidding with you. What everyone has been saying is good advice. Welcome to the forum and you made a great choice going with Smith&Wesson!

Nice of the dealer to offer to send it back for free since a call to S&W will result in a call tag being mailed to you so you can send it back for free without the dealer being involved.

I sent my M&P15 in last fall and actually had it back before I got the e-mail that Smith received it.

It's short stroking.
Possibly a gas issue, something along the lines of a too small gas port or partialy clogged (or crimped) gas tube.
Other possible reason would be wrong buffer or buffer spring.

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Hold my beer and watch this!