Is the castle nut on an M&P 15 staked?

__________________
No. Not me. I'm in my prime.

Is the castle nut on an M&P 15 staked?

__________________
No. Not me. I'm in my prime.

As the ol' sayin' kind of goes . . .

"Does the bear pizzz in the woods?"

Here's the Castle Nut on my brand new M&P15 . . . staked plenty well enough . . . but not TOO well as to prevent you from changing parts out, etc., if you want to!

It is staked in two places. The one pictured is the LEAST staked. They did it well.

I've been very pleased with this "S.U.R." (Sport Utility Rifle)!



Tom

Yep, everything on the M&P15s is properly staked.

If those castle nuts are torqued, I believe that 30lbs is the figure, but I'd have to re-check, they generally don't back out. I've not staked any on mine and they haven't budged. I know it was the original designer's plan, but the torque range on those rifles is so broad, it isn't really necessary.

The only thing that must be staked is the key on the bolt carrier, that will back out if it is not properly staked. Some folks say those should be staked in three spots each for each hex key, but others say two spots each. The rationale, I'm told, is that if one ever has to re-stake a key, then there will be more real estate if the key is originally staked twice. I've never known anyone who has had one come lose, so I would think that twice is enough.

Best,

Michael

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N-Frame-itis THERE IS NO CURE!

Yeah,

The only part not staked quite as well as I'd like is the bolt carrier.

Still, it seems to be ok. What do y'all think?



T.

Thanks for the pictures and comments, perhaps I should explain the reason for posting the question. I bought a M&P15ORC from Bud's because I couldn't find any M&P15 anywhere else, and because Bud's had a fair price on it. I live in SD where a compliant rifle isn't required. I don't care about it not having a flash suppressor or bayonet lug, the stock however is pinned in the extended position and I'll be wanting to change that when I finally get it. If unpinning the stock is difficult, or I want to change the stock completely, then removing the whole assembly would be necessary. I didn't know how difficult that might be if the castle nut was staked.

Tom, it looks like that bolt carrier should be fine.

__________________
No. Not me. I'm in my prime.

That looks adequately staked to me. It if worries you, make a witness mark with a scribe from the top of each hex screw across to the key. Check it each time you clean the gun and see if the hex screws are moving. I really doubt they will. If they do start to back out on you, I would take care of the matter buy getting a new key from Brownells, a good center punch, two new screws, snug them up as hard as you can with one hand in a standard screw driver -good and snug, then stake them with the punch. I think you'll be fine though.

FYI: the videos I watched, as well as some books, to learn to build ARs are:

http://www.midwayusa.com/viewProduct...tNumber=791160

http://www.midwayusa.com/eproductpag...eitemid=318780

I like them both quite a bit and Bob Dunlap is a hoot. He's got a little lisp and, not to make fun of him, but he reminds me of an elementary school teacher I once had. I like him, he's funny and know his stuff! I watched both videos probably 5 or 6 times each before I attempted my first build. In addition, I invested in all the correct tools. If you go to Brownells website, they have a video section that is completely free that teaches you how to build each sub-component of the rifle, as well as how to make sure it is safe for use; there is some great stuff here:

http://www.brownells.com/aspx/NS/GunTech/NewsletterArch...x?x=v&p=0&t=1&i=1103

If you are going to build one, and it's quite fun to do so; it's like assembling a model, get the right punches, etc. I just completed my first AR-10 build and had a great time (pictures forthcoming).

Best,

Michael

__________________
N-Frame-itis THERE IS NO CURE!

Could you show us some pictures of how the stock is pinned in? I'm not sure why that would be so, unless it is less than 26 inches with the stock fully collapsed. IIRC, the minimum length in the free states is 26 inches, out here in commie-fornia, however, the min. is 30 inches.

If you want to change out the buttstock, make sure you know what to expect, there is a spring captured under the plate that holds a detent against the rear takedown pin. You don't want to lose that or kink the spring when you put the stock on. I'd suggest watching the videos on Brownells website I posted above. You'll need a tool like this one:

http://www.brownells.com/aspx/ns/store/ProductDetail.as...4%20BUTTSTOCK%20TOOL

I got one of the multi-tools, I think from MidwayUsa.com. If you have to take the buttstock off, I don't think overcoming the staking will be too hard, but you might want to get a new plate so you don't have those unsightly marks and so you won't have to file the stake marks down before you put the new stock on. The parts are cheap, but new buttstocks can be expensive. I like Magpul and Vltor, I wouldn't go with any others unless I wanted a plain-jane A2 stock.

Best,

Michael

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N-Frame-itis THERE IS NO CURE!

I haven't received it yet, but I'll post a pic when I do. I like planning ahead. The S&W specs just say it's a compliant model with a "fixed pinned" stock. If all I need to do is punch out a strategically placed roll pin, then I won't have a problem. I've already built a separate lower, so I doubt there'll be any surprizes. I just didn't know if the staked portion would be a problem if I had to go that route.

__________________
No. Not me. I'm in my prime.

Not to change the subject (sorry) but my gas key screws are not staked like that....

I have heard that several different manufacturers supplied S&W with parts and assemblies for the MP-15. I believe that S&W has gone through a progression of the assembly of the guns over the past months. My M&P upper is staked very much like Tom Turners. The one you have posted is an interesting method, which I haven't seen often, since I've been playing with ARs. I really do believe that if the hex screw is good and snug, that it will not likely back out, even with a moderate stake. I think that the greater concern is that of the quality of the hex screws themselves, that they are hard enough so they don't stretch under the heat and pressures they have to endure. This had been an interesting thread.

Best,

Michael

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N-Frame-itis THERE IS NO CURE!

This is what I was afraid of. Here's a pic of my compliant fixed stock. Notice the pin in the stock itself. It doesn't go all the way through, so I can't just knock it out. Even if I could, there are no holes drilled in the bottom of the extension tube so I couldn't lock it in any position other than open. Fortunately, the castle nut is hardly staked, so removing the whole assembly should be easy. At least I can re-use the spring and buffer...

__________________
No. Not me. I'm in my prime.

I had a Bushmaster Varmint rifle that was not staked properly. I was at the range one day and could not understand why my rifle would not function. I was totally exasperated, I field striped the rifle and the key was so loose I could not believe it. I realized what the cause was and it was restaked, this time much better. Never had a problem after that. It is gone now so I don't have to worry about it.