Hello all! I’ve been using this forum for information for awhile now, but it wasn’t until recently that I decided to sign up and ask some questions for myself. I’ve just been involved in the gun community for a few years. I’ve been trying to soak up as much information as I can and put it to use everywhere I can. I had been saving money to purchase the new BCM MCMR rifle whenever it came out, but I’ve come across multiple people in the gun world who have been using AR pistols lately. I searched around and read some of the benefits of having an AR pistol so I thought to myself just build one of those and I’ll have the option to turn it into an SBR in the future. This would be my first build so I wanted to get some opinions of my fellow members in the gun community that have more experience than me. I’ve seen a few other threads like mine, but I didn’t want to hijack their thread. This is what I’ve got on my list as of right now. I’m trying to get most of this build out of the way on Black Friday deals, but I put prices I could currently find without searching too much. If any of you know where to look it would be greatly appreciated.
BCM MCMR Upper 11.5 or 12.5 with BCG and Charging Handle - $800
Aero Precision M4E1 or Mega Arms GTR lower - $120-$200
BCM LPK - $120
SBM4 - $150
BCM QD End Plate -$20
BFG Vickers Sling - $50
VLTOR A5 Pistol Kit - $110
Sight: Aimpoint CompM5, H or T series, EoTech XPS2 - $500-$800
Scalarworks Mount - $150
The barrel length and sight are the two biggest items I’m still debating right now. I might put a suppressor on it a few years down the road. I’m also wondering if there any parts that I’m not currently thinking of that I need for the build. I would love to hear what any of you have to say!
Looks like great quality component list. Back up sights are the only thing I see lacking. I mostly use Magpul MPro, but many low profile choices out there.
With a can in your future I’d go with the 11.5” for better balance. And the Mega Gator even if a few bicks more just because I like the logo and knurling on magwell front. The half dozen I’ve built have been problem free.
Have you gotten all the tools you will need? Besides the magwell block, punch sets, armorers wrench, and rubber/plastic mallet, the one I wish I had bought sooner is a long roll pin starter punch like this: https://www.rainierarms.com/kak-bolt-catch-roll-pin-starter-punch-walt-s-tool/
Relly helps avoid scratches. And tape off all around the hole.
Will Magpul iron sights rise high enough to see through an optic on a Scalarworks mount? I saw some nice fixed sights from Scalarworks, but I think I want ones that can be flipped down if I’m not using them.
I have most of the tools I need. I plan on watching a few more videos to see if I can pick up on anything someone else has used to make the process go smoother.
Also, to the other comments. I read good things about Aero and Mega lowers. I actually really like the way both of them look, but I’ve never seen a Sionics lower. I’ve read mixed reviews about the Shockwave as well. Some really like it, some don’t, but that’s what it is with everything. I’m going to give SB Tactical the first shot at my first use of a brace.
I looked at BCM AR pistols as well. Changing handguards, buying a brace, buffer kit, etc. would be more expensive IMO.
Yes, I use the Mbus Pros with Scalarworks co-witness for my MRO. Sionics quality IMO is on a par with BCM. I have uppers and lowers from both.
For braces I have tried the Shockwave, Thordsen, and several SB’s. The SOB is my fave. Hoping to find a sale on the SBPDW on Black Friday. Even after you SBR, a seperate pistol lower is handy for travel or to loan out. Be aware that pistol tube diameters vary. Baby powder will ease screwing it on. If too loose a turn of duct tape will make it snug.
The SBPDW was my first option as a brace. It costs a little bit more, but I’ve seen some people I like in the YouTube gun community (Lucas Botkin at TRex Arms as well as a few others) recommended the SBM4 so I think I’ll give it a try.
I’ve never had an Eotech so I would take AP over them since I have experience with them (and they seem significantly smaller than the Eotech). And of those AP options I would pick which ever cost the least and put the saved money towards ammo and/or your Scalarworks mount.
Suggestions in bold. I’m not really an experienced builder–have a 10.3 in construction and a 12.5 in planning myself–but I do have experience wringing value out of tight budgets.
How married are you to the BCM LPK? This weekend only, Dvor has CMC’s no-FCG-or-grip LPK for $22 shipped and AIM Surplus has the ALG QMS for $40 shipped–so that’s $62 plus grip. If you want an A2 I’ll GIVE ya one for just shipping–I have quite a few sitting around I’m thinking about trying to make into coatracks or furniture or something.
Optics? I’d love to try the CompM5. The earlier comps have all been great. Ditto the T1. (Spring for the t1 or 2 over the H.) I could not warm up to the Eotech reticle, but many like them. I do like the MRO.
If you want to splurge a little get a parts kit sans trigger/grip and upgrade. The Geissele SSA/SDC are the same except for contour. I love ‘em both - the single most important change that improved my accuracy. BCM mod 3 grip is very comfy.
that foregrip is not 90degrees therefore not a “vertical foregrip”
from another thread
ATF said:
For your information, Federal law currently does not define “Vertical Fore Grip”; however, ATF has determined that a grip of this type is distinguished by being both forward of the magazine well and oriented at a perpendicular (90-degree) angle to the bore of the weapon.
Interesting… ISTR that when Auto-Ordnance pistolized the Thompson they had to maintain above-26" to avoid AOW status with the classic 45-degree-ish “Chicago Typewriter” foregrip. I do know that Magpul AFG and FAB PTK are considered non-AFG since I have their Determination Letters.
I’m also interested in more information on that canted/slightly angled forward grip…I have 2 or 3 of the BCM style “canted” stubby vertical grips and would love to put one on my pistol in place of the AFG currently there…does anyone have any other links to threads or documents that have more information on that?
Thanks in advance!
Mine pistol is way under 26" so it’s definitely a pistol, but I love that BCM style canted grip on my registered SBR.
