BCM Reinforced AR15 Upper Receiver

mebiuspower

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Is it just me or is this yet another glorious solution to a problem nobody had?

Not true. The upper receiver does flex under recoil.

http://www.militarymorons.com/weapons/ar.uppers.html

Larue Stealth:
Reduced receiver flex is another step towards increased accuracy/consistancy under different shooting conditions and positions, and the STEALTH receiver has been beefed up and reinforced in those areas which LaRue feel are the important ones.

Vltor MUR:
So, why get a MUR? Most don't need to replace their standard receiver with a MUR. But some users will appreciate a stiffer, more rigid upper receiver that's correctly machined to spec, looks better (in my humble opinion) than the standard receiver, and the knowledge that it comes from Vltor, which I consider a leader in innovative and practical design in the firearms industry. Or sometimes it's just nice for us guys to have cool new toys.

http://www.m4carbine.net/showthread.php?57-Upper-Receiver-Flex-Testing-Part-One
http://www.m4carbine.net/showthread.php?58-Upper-Receiver-Flex-Testing-Part-Two
 
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I'd be interested to see how much of a difference it made if you were going for pure accuracy. Like an SPR type build or target rifle.

Not so much on that kinda carbine.
 
Don't get me wrong, I fully understand that receiver flex exists 100% absolute.
I just don't see the problem, not once have I ever heard of an AR shooter complain of receiver flex, or receiver flex causing any noteable issues or defects in a rifle.

Me thinks this is just another "staying ahead of the curve" release. That being said, I can't see this as a bad thing, just another pointless endeavor designed to grab your cash.
Like Joel said, maybe if you're splitting hairs chasing 1/4 moa, maybe. But on your basic b!tch AR15, nah.
 
I don't think it matters for a 5.56 rifle or even for most of the shorter 7.62 gas guns either.

If I am thinking of something going over 600m all the time and out to 900m+, that extra weight and whatever that extra accuracy produced may mean more.

For a 200m or even 300m gun, that doesn't matter at all.
 
the one thing that is rarely thought of is what happens when you have a kaboom. This reinforcement may help protect the shooter in case of a failure.

Boltgun
 
Check out the following video from SnipersHide where he visits Seekins Precision to talk about their beefed up large frame receivers. If you want a semi that is at the top of the pile for accuracy the flex in the receiver does make a difference.

https://www.youtube.com/channel/UCwHsnyWOaQNtrGjJKsTgegg

Reinforced AR upper receivers are already a 10+ year old when Larue and Vltor released their uppers and I'm surprised people on CGN are questioning it now.
 
I have a Larue Stealth upper mated to a 24” HB Krieger that I used to shoot farely regularly out to 600-800m.
Before that barrel was on the Stealth upper it was spun onto a plane jane Eagle Arms (Armalite) upper.
In both cases a floating 15” JP tube was used.
I didn’t notice any apreciable differences, even when slung up tight with my jacket on.
I dont have a lot of miles on in either configuration though, so if a guy was to want an upper to last through several barrel changes, was constantly putting pressure on the upper or the tube (like high power shooters do), or just wanted piece of mind and deep pockets, then I can see going this route. However, if one is really concerned with the miniscule differences it makes, then they should probably be looking at a monolithic upper.
 
Reinforced AR upper receivers are already a 10+ year old when Larue and Vltor released their uppers and I'm surprised people on CGN are questioning it now.

It's not a matter of questioning its purpose, I just don't see what problem it resolves.
I've dealt with issues like over gassing, undergassing, free floating vs not, reciprocating mass issues, spring tension problems, but never once have I ever heard one person ever say "my upper receiver flexes too much" or "receiver flex causes problem X".

Comparing this to an IUR or MUR upper doesn't seem like a fair comparison either. One integrates the rail (as I know you know already) where as this BCM upper merely beefs up an area that does flex, but hasn't seemed to ever cause any noteable problems.
 
The revolutionary changes are made at the fringes by small companies. My brother is a trained technical minded fellow, and a licensed international parachute rigger instructor (not many people get paid teaching holidays to help rebuild another country's parachute federation programs). He tells me that the good ideas always appear on the edges of the sport. One guy (or girl) will have an idea, and when they get it into production, other people begin to notice. Next thing, that innovation is mainstream. In the AR community, how many people groused at cheesegrater foreends and hanging stuff off the sides? Now you can hardly buy an AR that isn't offered with unconventional front end. How about flat-top receivers, or low-profile gas blocks, or upright pistol grips? Those ideas didn't "just" happen.

In the 90s I was teaching hunter safety in Saskatchewan. We had all kinds of propaganda and truly BS training material that the federal program foisted on us. There was one VHS tape in particular that showed in all seriousness that Remington 700 receivers were designed to fail (!) and as instructors we were to position ourselves on the left side of the shooter - because the ejection port would funnel whatever exploded debris at us. I flipped! And, sent the tape to Remington and the federal program, telling them both that the material was slanderous and highly prejudicial. Remington thanked me for it, and I think they told off the feds.

In the context of BCM's heavy upper, I can see it having a place as a range gun or a course loaner at a facility that will shoot tens of thousands of rounds a month. Without saying it, Vickers implied that under heavy use any AR could flex enough times to let go. Maybe it hasn't happened yet, but lawyering up with extra rugged rifles might be just enough precaution for a commercial operation to avoid a wrongful death lawsuit.
 
Yet they kept that god damn useless forward assist in their design. That's just retarded.

There are Vietnam M16's still kicking around being used in foreign conflicts that have seen an absurdly high amount of rounds and use that are still working, albeit having a fiew missing or replaced small parts, so this is pretty much a moot point.

Reinforced AR upper receivers are already a 10+ year old when Larue and Vltor released their uppers and I'm surprised people on CGN are questioning it now.
Weren't those 6061?

the one thing that is rarely thought of is what happens when you have a kaboom. This reinforcement may help protect the shooter in case of a failure.

Boltgun
Nope. If you have a kaboom of receiver-splitting proportion, that is, the kaboom is so huge that the downward-venting design of the bolt carrier is not keeping the upper together, it won't change a damn thing.

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Pictures taken from an american forum.

This was a Colt Expanse rifle, and the ammo was Federal 5.56. This ammo has caused A LOT of kabooms in the US.
 
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I was shooting beside a guy whose SAFN failed. He had a buttstock in one hand and a front heavy fore end in the other, connected by the sling. His mag blew down and the stock shattered. But I'll save those AR kaboom shots for reference. Always good to see where the failure points are.
 
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