BCM Prototype upper?

[ALCOAR]

TBH, this is really a product in search of a problem. With all the potential compatibility issues, and the fact that standard upper receivers are perfectly fine, I really don't see why somebody would want one of these new upper receivers. If I felt I needed the absolute best upper receiver for a build, I'd go with a MUR.

Nothing wrong with making new products in order to make money, but I I can think of a ton of other true enhancements for the AR rifle that I'd prefer over this particular upper receiver.

[26 Inf]

Could be the Rosco barrel, I put my 11.5" Rosco in the freezer for and hour or two to get it to fit into the Aero upper I was building.

Stainless? How does it shoot?

This is my first Roscoe barrel, I wanted a 13.7 and they were pretty reasonable.

[Wake27]

TBH, this is really a product in search of a problem. With all the potential compatibility issues, and the fact that standard upper receivers are perfectly fine, I really don't see why somebody would want one of these new upper receivers. If I felt I needed the absolute best upper receiver for a build, I'd go with a MUR.

Nothing wrong with making new products in order to make money, but I I can think of a ton of other true enhancements for the AR rifle that I'd prefer over this particular upper receiver.

1. Potential accuracy improvement
2. Potential durability improvement
3. Potential gas to face improvement
4. Definite improved compatibility with ambi charging handles

If it works with BCM rails and the URX 4, sounds like it could be a solid win.

[26 Inf]

In my sample of two BCM uppers (new blem and non-blem) vs two Aero uppers (both new):
Aero uppers had a tighter barrel fit and much better lower to upper fit vs BCM. BCM were not a tight fit at all for barrels and were pretty sloppy for upper to lower fit. Barrels tried - BA, Rainier CHF, Colt. At that point I figured that BCM mil-spec uppers were probably over-hyped for what they were and just not worth it for me. Maybe I got out of spec or edge of the spec BCM uppers both times - who knows. Again, this is my personal opinion and limited experience.

I find it disingenuous for BCM to claim that their MK2 upper is fully mil-spec compatible, yet fail to mention that most popular aftermarket rails (Geissele) do not fit. BCM MK2 upper has been seen in a public for at least two years - I find it impossible to believe that BCM did not test with the Geissele rails.

I'm far from a BCM fanboi, but I find their blem uppers to be a very good value. This upper, the MK2, is the first new stripped upper I've bought from them, I've never had what I would describe as loose barrel to receiver fit.

I've used/instaslled their uppers on numerous brands of lowers and never noticed excessive looseness, so I can't speak to that.

TBH, this is really a product in search of a problem. With all the potential compatibility issues, and the fact that standard upper receivers are perfectly fine, I really don't see why somebody would want one of these new upper receivers. If I felt I needed the absolute best upper receiver for a build, I'd go with a MUR.

I tend to agree, the reason I bought one was as a lefty to see if moving the FA forward made any difference in charging handle manipulation, which, truthfully, isn't much of a problem to begin with.

Gee, now I want a refund.

[CrowCommand]

Stainless? How does it shoot?

This is my first Roscoe barrel, I wanted a 13.7 and they were pretty reasonable.

4150 Nitride. It shoots well, but I haven't really had the opportunity to see what it can really do. It wears an Aimpoint PRO, looking into a Px4i so I can try it with some magnification. No problems ringing 8" steel at 200 yd with the RDS, though.

[Stickman]

1- TBH, this is really a product in search of a problem.

2- With all the potential compatibility issues, and the fact that standard upper receivers are perfectly fine, I really don't see why somebody would want one of these new upper receivers.

3- If I felt I needed the absolute best upper receiver for a build, I'd go with a MUR.

4- Nothing wrong with making new products in order to make money, but I I can think of a ton of other true enhancements for the AR rifle that I'd prefer over this particular upper receiver.

1. If you are unfamiliar with the aspects of the weakening which occurred with the removal of the A1/ A2 carry handle, you might want to brush up. The carry handle was a reinforcement designed into the weapon from the start.

2. The "fact" that standard receivers are fine? That will depend on the aspects you are talking about. If you are meaning bolts breaking early than before due to flex, or less than trued faces, sure, modern, in spec receivers can be very functional.

3. If you felt like you needed something..... the key to most of what you posted is you. YOU don't see a need. YOU would rather get something else. YOU want other enhancements. The MUR is fantastic, and now BCM has come along with something which is similar while a fraction of the price.

4. There are loads of enhancements for the AR15 series of weapons. The individual shooter/ owner needs to make choices as for what their own particular needs are. That doesn't change the BCM creation is stronger, and held to higher tolerances than standard receivers. Nor does it change the built in gas dispersion.


You have a hard time arguing any of the shown improvement points of the BCM new receiver. In fact, I don't see where you have even talked about the item itself. The closest you have come is in talking about compatibility, and while there will no doubt be some rails that don't fit, it isn't the job of BCM to shoe horn their design ideas or project improvements into the given design of other manufacturers. What the receiver will do is work with all standard milspec components, and the vast majority of commercial ones.

I'm not sure you and I are actually arguing over anything on this, I think we are probably just looking at it from different angles.

[opngrnd]

I'm looking for an upper receiver with improved rigidity and tight fit for a non-free floated FSB based mid-length. This option keeps popping up in my mind. Would it provide any additional protection in the event of a Kaboom like the MUR does?

[JediGuy]

I'm looking for an upper receiver with improved rigidity and tight fit for a non-free floated FSB based mid-length. This option keeps popping up in my mind. Would it provide any additional protection in the event of a Kaboom like the MUR does?

I believe that’s part of the design purpose, moving the mass around to a more kaboom-tending area.

[AAMP84]

Came across this video this morning of Paul and Larry discussing the MK2 upper.
https://youtu.be/DLAe5RjDNys

[opngrnd]

Came across this video this morning of Paul and Larry discussing the MK2 upper.
https://youtu.be/DLAe5RjDNys

Thanks for sharing. He hits on all of the points I was asking about. And it's out of stock!