m&p15. identify barrel.

tatarica762

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Hello.

I'm trying to identify the barrel twist rate and if the barrel is a 223 or 5.56.

This is on an M&P15. This is the lower: (normally it should say the caliber on the lower right under "M&P 15" right?

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...and then both sides of the barrel. There is no identifying marks on the bottom of the barrel. I haven't removed the rail to see if there are any marks under the barrel there. (are they normally in that location?)

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Thanks guys!
 
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How does one verify if an upper is a S&W also? I think this is a factory gun but I can't tell for sure.
 
Mine is stamped on the top of the barrel between the front site and the flash suppressor
 
i don't have a tool so I can't remove the handguard. I can see below the rails though and it's not marked (unless it's UNDER the handguard but it has a metal shield so I can't see through the hole).

Nothing stamped on the top of the barrel between the front sight and flash suppressor.
 
So you know in the future Tata, the lower most times will not have a caliber stamped on it. With all the different uppers that you can get in different sized calibers, you would have a book stamped on the side of the lower. That's the beauty of the AR style rifles. You can change what your shooting very rapidly.
Did you buy this firearm new and used. With new ones you don't have to worry about uppers getting swapped around. If it is new, you can call the S&W CS. and give them the SN off the lower and they can tell you how the firearm left the factory. They can tell you how the lower left the factory anyways. That barrel is going to be stamped somewhere on it. If you bought it at a gun shop, take it in with you and ask them pop the hand guard off so you know what you have. That's just good customer service. From the looks of it, My money rides on you having 5.56 with a 1/9 twist(maybe)
 
sorry to say but all m&p uppers are stamped in between flash hider and front sight


fear the free
 
Are there any other marks on a S&W upper? (to verify if this isn't a factory built gun, what upper is it?)

(the finish from the lower to the upper is the same (i know, that's not very telling)).

Rifle was acquired used; I'm not sure the history. The inside doesn't look too used. No slop between upper/lower. Is the BCG usually marked?
 
I've emailed S&W customer service to run the background on the SN. I figure that will at least tell me if it started life as a stripped lower.
 
I found this video to describe various BCG's including a S&W.

AR-15 Bolt Carrier Group Comparison - YouTube

- Mine isn't as staked as the sample S&W in the video.
- It does have the more massive back part
- It does have the shrouded firing pin

I can't tell if it's been shot peened. or if it's a black or blue extractor.
 
Thats a great video, Ive watched it before. Makes me glad to own a S&W
 
All the S&W bolts I've seen are market "MP". It's a semi auto carrier. Barrels are stamped with the twist rate and caliber just behind the flash hider. Sounds like you might have an unknown upper mated to a S&W lower. You can call S&W with your serial number and they can tell you if it was sold as a stripper lower also.
 
my m&p sport is stamped on the bottom of the barrel between the front hand guard and flash hider. 223/556 1/8 5R is what it reads
 
I contacted the original owner and got more info. It was built to order for him. But this is the info from the spec sheet:

- 16" 5.56mm caliber barrel, threaded the standard 1/2 x 28, A2 flash hider with the correct crush washer
- forged A2 front sight base with bayonet lug (not the cheaper cast front sight base).
- Chrome-moly, high vanadium steel and hardened to a U.S. government Mil-spec of Rc 26-32.
- Manganese phosphate finished IAW 5.3.1.2 of Mil-STD-171
- Mil-spec M4 contour (.750 under the front sight base) complete with the M203 groove in the front.
- Button rifled with 6 grooves, right hand, 1 / 9" twist.
- FORGED A3 upper receiver with built in Mil-spec M1913 Picatinny accessory rail, made from certified 7075T6.511 alloy forgings, hardcoat anodized IAW Mil Spec A8625, Type III, Class II, black per No. 37038, Table IX with nickel acetate seal, as per the Mil-spec

Any feedback on this barrel based on the info above?
 
Well... she's not a pure bred S&W after all. I braved the cold and took her out to the range. And she performed. Here are some pics:

34yv3t1.jpg


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(Target was at 50 yards. Orange sticker an inch. Black box Federal 55 grain from Walmart. 1st group was the top after 20-30 rounds of just getting used to the rifle and making some adjustment. 2nd group on the right was actually 3 holes (2 in the upper right). 3rd group I aimed slightly low from center and it still produced (actually the best group). 4th group on the left was trying some unknown 5.56 in a friend's pocket).
 
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it looks like she shoots well and consistent. Now just comes the matter of you learning your rifle..
 
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