S&W AR-15 BCG

IronSkillet

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Shopping for another AR-15 and being of the A2 generation lots of things have changed in this market. Currently considering these 3 AR's: 1. S&W 11515pc
2. S&W 13492
3. S&W 311053LE or the 54 version

My question is this; unable to locate information if all S&W AR under go MPI and or HPT inspections. These inspections are mentioned by many of todays manufactures but it appears somewhat vague for S&W.
Watching a YT video review of the 11515 the reviewer appears somewhat surprised by finding MPI etched onto the bolt during his presentation. My take-away was that all S&W BCG do not receive this inspection, please advise.

Although the 18" barrel on the 11515 is desirable it is the most expensive rifle of the three.
The 13492 pretty much covers what my current needs are, (not sure about a flat trigger).
Last is the 311053LE (54) a mega online dealer has them in stock and is is under 1K ( would find parts being swapped out)
making it the lowest priced rifle of the 3.

any additional information for these rifles would be greatly appreciated.
 
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I don't have a clue on the parts sources or inspecton protocols on the parts used on the S&W M&P 15's. I have a few comments based upon time spent as a production machinist and long time user of whatever AR variants I was issued.

When the AR concept was developed, both steel making and machining had come a long way from WWI tech. However, we've come much further since then. The materials used today are much improved in uniformity of formulation and the machining and heat treat are much more precise.

The developer of the AR was Fairchild Industries, an aerospace firm. Every cotton picking part of an aircraft is both individually inspected at each production step and tracked in a manner similar to an evidentary chain. Most parts in other industries are inspected on a more relaxed basis, like 1 part in 10, 1 part in 100 etc. If a defect is noted, the lot of parts gets a more detailed inspection. Given Fairchild's background, the fact that the AR was a revolutionary design and that at the time, most Government contracts were "cost plus ten (per cent)", OCD part inspection really shouldn't have been a surprise. Business as usual and the higher the production cost, the higher the profit. When Colt got the production contract, they also got the process from Fairchild, although they may have made some slight changes to facilitate mass production.

This creates two questions: Is MPI on each individual part really necessary today or is it guilding the lilly? Could every bolt be MPI certified and the marking eliminated as not part of the contract and/or to save costs? I personally think it's guilding the lilly, but if you insist, a "MPI bolt" could be headspace checked and installed.

FWIW, we used ARs in a manner termed "abusive" by several manufacturers. We found that S&W ran right along with the Colts and had a better warranty. Also, FWIW, cracked bolt lugs and cracks in the bolt body at the cam pin hole seem to be a common thing in hard used ARs, MPI or not. But that's gonna take a long time.
 
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WR Moore, thanks for your comments. Do you believe the HPI the BCG is also guilding the lilly? How about buying full auto BCGs for use in regular semi-automatic AR-15s?
 
I expect the HPI test gets done on the bolt. But, like with the MPI, it may/may not be each and every one. If not done as a separate step, the proof testing of the assembled rifle will do so. The entire BCG is not high pressure tested.

The difference in weight between the semi and full auto bolt carriers is operationally insignificant. The extra material is there to operate the full auto sear. If for some reason you feel you just gotta have that extra weight, the cheaper and easier way to do it is to replace the bolt buffer with an H buffer. The H2 bolt buffer with sliding weights is used in the full auto version to curb bolt bounce. This isn't a factor in a semi-auto rifle.
 
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WR Moore, thanks for your comments. Do you believe the HPI the BCG is also guilding the lilly? How about buying full auto BCGs for use in regular semi-automatic AR-15s?

I use only the "full auto" profile BCG's. I like how they run, i.e. smoothly, versus the AR-15 profile carriers.

There are other things that effect the velocity of your BCG while shooting, but using a full profile carrier is a step in the right direction. JMHO
 
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