BCM Prototype upper?

[26 Inf]

I have other gas mitigating features (small gp barrel, Gemtech BCG) but this upper spits gas and oil right into my shooting eye. I’ve never had any other rifle do that. It might mitigate gas but the small amount that remains is ejected in a shitty spot

Just out of curiosity, what charging handle are you using? (I assume since it's getting you in the eye it's either around charging handle, or out the upper/lower joint in the RE area.

[RHINOWSO]

I'm sure it'll be great, but not something I feel the need to be an early adopter / potential free beta tester for.

[Vegas]

I have other gas mitigating features (small gp barrel, Gemtech BCG) but this upper spits gas and oil right into my shooting eye. I’ve never had any other rifle do that. It might mitigate gas but the small amount that remains is ejected in a shitty spot

Well that is no bueno. I ditched a blowback 9mm AR for the same reason. Different animal of course but life is too short suffer things that don’t work when there are alternatives that do work.

[Jliddle]

Does anyone have any further feedback/report on these new uppers?

[opngrnd]

I have one on the bench and a BCM rail inbound. It doesn't fit up against a DD, ALG, or Larue rail. I can confirm a very tight receiver extension fit.

[1168]

I’ve got one with KAC URX4 and a BA 11.3” barrel. Handguard fits just fine. Getting the barrel in was a huge pain, however. It doesn’t gas me out too bad, but there’s so many factors there that I can’t say for sure that the receiver helps. The can I’m using with that has a lot of backpressure, so every bit is welcome.

[26 Inf]

Does anyone have any further feedback/report on these new uppers?

Yes. I have one.

I have not used it suppressed because I put it on my primary range rifle.

I'm a lefty, so I was anxious to try the upper because of the forward assist being located further forward. The design is intended to put less gas into your face out of the FA and to make it easier for a lefty to use an ambi charging handle.

I the standard FA channel begins at an angle with the beginning of the angle blending into the back edge of the upper receiver. The BCM modifed upper's FA is fully an inch and a half forward of that location.

Comparison of FA: https://gastatic.com/digest/wp-conte...t-1024x683.jpg

Comparison of left side: https://gastatic.com/digest/wp-conte...t-1024x683.jpg

The receiver - barrel extension interface was snug, I lubed my extension with anti-seize, and gently seated the barrel with a rubber mallet. Normal for BCM, I've never had to heat one.

In actual use, I didn't see much gain from the relocated FA, but that was probably due to my ingrained habits. I 'hook' the charging handle at the distal joint of my right index finger in order to clear the 'old' FA and that habit is ingrained. There is no doubt that the MK2 forward assist location allows you to put more real estate onto the upper.

All in all, I don't regret getting the upper, but I'm going to pass on it for future builds until BCM starts selling them as blem/demo uppers.

Apparently, at this time BCM is only selling the MK2 with assembled uppers. From what I could see, the price increase is eleven bucks over the same standard upper. If I was buying an assembled upper, the extra eleven bucks would be a no-brainer.

ETA: Gas. As I said, I don't use this suppressed, and I don't do mag dumps, even as a lefty, gas generally isn't a problem for me, I didn't notice any difference in that respect while shooting this rifle.

Hope this helps.

[Stickman]

Does anyone have any further feedback/report on these new uppers?

Like what?

[Jliddle]

Like what?

Yes to be more specific. Im looking at the 14.5" mk2 vs the standard 14.5" which will primarily be used with my Omega.

If the alleged gas reduction benefits are worth the extra wait time and $25, I'm all for it.

[Cameron]

I just bought a BCM MK2 upper yesterday (actually bought a complete upper receiver group) and was looking for info on this receiver. I found this video:

BCM MK2 Upper Receiver - Vicker's Tactical YouTube

Didn't see it posted in the rest of the thread, excuse me if I missed it.

Cam