Hey guys I have had my M&P 15 for a while but only shot it once it really needs optics but I am having a problem. Mine will not completely seat the bolt onto the round in the chamber. I have to use the bolt assist every time. Can someone please take their S&W bolt out and see if they can easily move their extractor back and forth I am thinking my is binding and this is the problem but not sure.

Thanks

I don't have mine here in the office to look at - but remember, any new AR likes to be "wet" when shooting. Use a lot of lubrication, especially for the first few hundred rounds.

My MP-15OR has never needed the forward assist. I'll check on the extractor when I get home.

Bob S.

Great let me know what you find on yours.

Thanks

OK - I took the BCG out and the ejector moves freely, but the extractor does not move easily. I pulled the one on my LMT upper, and it's the same way. It took a lot of pressure to get any movement.

With the extractor spring working as it should, the extractor only moves a very small amount. It just needs to be able to move enough to let the extractor snap over the rim of the case.

I still think a good cleaning and a bunch of lube will be your best next step. Also make sure the chamber gets a good scrubbing - make sure its good ammo too.

Take care,
Bob S.

You can try a few things. Remove the extractor and inspect it for burrs or damage. Clean the extractor and under the extractor very well. Replace the extractor spring, they are only $2. Ensure the bolt and star chamber are clean and the bolt is lubricated well. Finally remove, inspect and clean your buffer and buffer spring. When you reassemble, ensure the bolt carrier group and receiver are well lubricated, then spray some CLP or Rem-oil in their right before firing the rifle. I don't like an AR dripping wet because I don't really like vaporized gun oil in my face, but they do need to be well lubricated especially when brand new.

When I got my M&P (new), I disassembled it and cleaned it. Then I lubed it as follows ("grease" is synthetic axle grease - I happen to use Valvoline DuraLube):

Thin coat grease on the firing pin, with the excess grease wiped off.

One drop of Remoil (or your favorite gun oil) on the bolt's gas rings.

Grease on the lug (not in the hole of the lug, just the outside that comes in contact with the bolt carrier).

After the BCG is reassembled, wipe it down with a cloth, and apply grease to the rails (or what could be called rails).

Apply grease to the top/sides of the charging handle, and then wipe off the excess.

On a new rifle, I oil all the pins on the lower as well. One drop each is enough.

Make sure your chamber is clean.

One thing you didn't mention is your magazine. It could be defective.

Also, you didn't mention what ammo you are shooting, but if you're going to use steel-case ammo, avoid switching to brass (or vice-versa) without cleaning the chamber first.

A couple of people have mentioned that a new AR should be run "wet", but I don't really see the need.

That is BAD Deja vu for me.

My original would not move by hand. No how, no way. My bravocompanyusa.com bolt I replaced it with is good.

Please let us know how this turns out. Especially how S&W service works for you, if you use it.

Best of luck.

I have to ask this to rule it out. Are you releasing the bolt carrier and letting the force of the spring chamber the cartridge or are you using the charging handle and riding it forward with your assistance?

^^ I assumed he meant this was happening every round while firing, but this is a good question.

A $2 spring would have worked, no need for a $70 bolt.