BCM 9" 300 Black out or sig MCX?

[ICEMAN550]

I am looking for a compact AR and was planning on buying a BCM Upper 9" 300 Black Out on a lower and register as a pistol on CCW. I am in NY and can't get SBR. I have a DDM4V11 and a S&W Sport (older style). That S&W Sport is the best $500 spent on a rifle. I have ran it hard trying to make it fail, but after 5000 rounds (mostly xm193) and not a failure. The DD is my go to rifle set up with aimpoint, mbus, mpul verticle grip and light. I am almost sure I want the 300 BO pistol, but after seeing a few videos on the sig mcx, I wanted to get some opinions. I like the folding stock and lack of buffer if it as reliable as some of the reviews. The MCX would fit the role I am looking for without giving up barrel length. If I could get a suppressor in NY I would lean more to the pistol AR in 300. I will hopefully be out of NY in less than a year so that will open up more options. All opinions are appreciated!

[Joe R.]

I have a Sig MCX in 5.56 and at this point I'd recommend the BCM. While the Sig has some very desirable features it falls short in some areas. The accuracy in my and some friends MCXs is very ammo dependent (5" with xm193 at 50 yards and 1/2" with Hornady GMX at the same distance). Along with this there is the issue of parts availability. While I understand Sig is good about sending out replacement parts they are the only source. If your BCM goes down AR/M4 parts are abundant.

If you want the smallest possible package look into the Law tactical folder as an addition to the M4 platform.

[ICEMAN550]

I have a Sig MCX in 5.56 and at this point I'd recommend the BCM. While the Sig has some very desirable features it falls short in some areas. The accuracy in my and some friends MCXs is very ammo dependent (5" with xm193 at 50 yards and 1/2" with Hornady GMX at the same distance). Along with this there is the issue of parts availability. While I understand Sig is good about sending out replacement parts they are the only source. If your BCM goes down AR/M4 parts are abundant.

If you want the smallest possible package look into the Law tactical folder as an addition to the M4 platform.

Thank you. The accuracy issues with the MCX would be disappointing. I am curious to why there would be such a difference especially 5'" at 50 with xm193. I am not as worried about replacement parts since I have other AR's and extra parts for them. I will probably go with the BCM 9" in 300 BO. The MCX seems like an interesting rifle and I have had very good luck with my sig P229 and 1911 tacops. I will take a look at the law tactical folder too.

[vectorsc]

I like to have nothing on my rifles that isnt identical in operation and feel controls wise. Same triggers, charging handles, safeties etc. I dont go with the sig for that reason.

[rapomstage3]

I like to have nothing on my rifles that isnt identical in operation and feel controls wise. Same triggers, charging handles, safeties etc. I dont go with the sig for that reason.

Sig/mpx/mcx manual of arms is identical to an ar. Only thing is you can't change the charging handle. I have an mpx and there is no difference other than lack of recoil. That being said I have a Bcm 9" blackout Sbr and it's the nuts. I'm not sure there's a more badass setup on the planet. My vote is Bcm go get it.

[Renegade04]

I have a Sig MCX in 5.56 and at this point I'd recommend the BCM. While the Sig has some very desirable features it falls short in some areas. The accuracy in my and some friends MCXs is very ammo dependent (5" with xm193 at 50 yards and 1/2" with Hornady GMX at the same distance). Along with this there is the issue of parts availability. While I understand Sig is good about sending out replacement parts they are the only source. If your BCM goes down AR/M4 parts are abundant.

If you want the smallest possible package look into the Law tactical folder as an addition to the M4 platform.

If you are getting 5MOA@50 yards with XM193, either there is something wrong with your technique or the SIG. I had mine out yesterday and at 50 yards, I was getting about 2MOA (with Federal XM193) without even trying to be accurate. This was just putting the red-dot in the vicinity of where I wanted to hit.

I will say this, the SIG MCX has one shortfall from the factory - the trigger. It is very heavy. I installed an ALG ACT in mine and it is great. I also installed a new VORTEX SPARC AR red-dot.

[Mrgunsngear]

Sig/mpx/mcx manual of arms is identical to an ar. Only thing is you can't change the charging handle. I have an mpx and there is no difference other than lack of recoil. That being said I have a Bcm 9" blackout Sbr and it's the nuts. I'm not sure there's a more badass setup on the planet. My vote is Bcm go get it.

Can't argue with that.

[Joe R.]

Renegade04 I'm pretty sure my technique is solid. While I'm no Carlos Hathcock I can certainly shoot better than the rifle did on that day with that ammo.

I actually went out yesterday with the MCX just to shoot a series of groups with different ammo to see what results I got. The xm193 (all LC marked cases) shot 2" with one flyer that was 6" from the rest of the group. I'm writing this off to the ammo as the results I achieved from the other ammo types had more consistent results. The only round that it did not seem to like was Winchester M855 resulting in a 2 1/2" group. Best results were with Federal Gold Medal match (69 gr BTHP) and Asym 70 gr TSX with both resulting in sub 1" groups.

While my results were better then the previous performance with xm193 I'm still not ready to put full faith into this particular MCX. If it were just a single incident or just the particular MCX I own I'd write it off as an aberration, however friend and mentor Ken Hackathorn just picked up an MCX and is experiencing the same inconsistent accuracy results with xm193.

Even if the MCX was a 100% my advice to the OP would be the same, go with the BCM. Pure logistics point toward the BCM as the logical answer.

[quino171]

I am looking at Sig to replace most of my collection. An MCX and all its components and P320 would be awesome.....add in an MPX and set

Sent from my A0001 using Tapatalk

[_Stormin_]

Another BCM 9" 300BLK owner here. Love the thing. It's probably my current favorite set up.

Terrible phone pic.

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Waiting on the T2 for it. I figure that it would be best kept light and after a range trip with an Aimpoint Pro, it felt like the optic was 10% of the total mass of the gun.