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Next PCC Build: CMMG Colt Pattern Lower, Super Short Barrel

Discussion in 'Pistol Caliber Carbines' started by JRHorne, Jul 12, 2017.

  1. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Finally decided on my next PCC build. I had long thought it would be a Glock pattern lower, since I have a 19 and 17, so ETS and big Glock mags could be used by all. Realized a couple of things though that pushed me towards a change of heart.
    1: I hate the angle of the long Glock mags coming out of the bottom
    2: I finally figured out that the smaller magwell (small frame like QC10, etc) are what also makes the gun look weird.

    So I solved both by ordering a CMMG Colt Pattern stripped lower this morning. It is the size and shape of a standard AR15 lower, but the magwell is cut for the Colt mags. And the mags go straight down out of the bottom, which I like.

    As soon as I get the lower, I will go ahead and file the SBR paperwork. I think I will plan on running a 4.5" Faxon barrel with the CMMG BCG. That way I can use my BCM trigger from my PWS Mk1 Mod2 when I receive the Zev they owe me. Also going to use the LWRC Ultra Compact Stock Kit and will get the JP Silent Capture Enhanced Gen2 and modify it to work with the LWRC stock. Also found a YHM 9MM marked upper on clearance and decided to order that in the event I decide no to cerakote the receivers and rail. Kind of a cool visual reminder that the gun is 9mm:

    YHM1009MM.jpg

    Still undecided on three things:
    1: Which rail to go with? Likely will need to be a 4.5-5.5'' one.
    2: Which muzzle device to use. I like the looks of the Kaw Valley 9mm Linear Comp. I do plan on a 9mm suppressor soon
    3: What color to cerakote the receiver setup and rail. If I do, I am thinking Tungsten Grey.

    Basically, going for this look (but with the nice full magwell), plus an MRO or T1
    DD1EFDE0-A922-4AEA-B782-768171D699EA.jpg
     
  2. Slacker

    Slacker Liquor and Whores...

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    I have a CMMG 9mm BCG. It has held up really well. It does not reset the S3G style hammer, not sure if the BCM trigger has a standard hammer profile or not.

    The Gibbz side charger upper is super nice. Billet, beautiful machine work.
    Very nice lines and works like a dream.
    Very nice with a suppressor since it seals the rear of the receiver.
    That gas gets really old, especially if shooting inside and rapid fire.

    I also use the JP SCS and really like it.
    The CMMG bolt has a pinned in weight, so it's easily removed to allow the JP guide rod to do its thing.
     
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  3. JRHorne

    JRHorne Well-Known Member Supporting Member

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    The more I read, the more I was convinced of CMMG. People have been running the crap out of them for 5-7 years and it seems like they are almost boringly reliable.

    I have a few options on trigger including the BCM, an ALG ACT, of course standard milspec, the Zev, and a LaRue MBT2S I could try out.
     
  4. BigWaylon

    BigWaylon Head philatelist Staff Member Benefactor Charter Life Member

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    My 9mm SBR has the YHM upper as well. With the 9mm marking, I opted not to engrave anywhere else...right, wrong or indifferent.

    Mine has a Hahn buffer and Hahn dedicated mag block.
     
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  5. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Last edited: Jul 12, 2017
  6. BigWaylon

    BigWaylon Head philatelist Staff Member Benefactor Charter Life Member

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    Not actually sure. :oops:

    I bought a complete JSE upper and opted for the $10 upgrade for the YHM upper receiver. I checked the part number against their site and it's not found. Looked at what I think is close to the same thing and it simply says:
    • Bolt Carrier Group - 9MM Ramped Bolt Carrier Assy
     
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  7. JRHorne

    JRHorne Well-Known Member Supporting Member

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    As I continued to read and explore options, I found out there are a LOT more barrel options than I anticipated, and fewer super short handguards/rails than I anticipated. Many folks seem to go with a 5.5" barrel just because of the handguard options. I am not against that, but think I may just order two barrels and then a few handguards and see which combo I like best.

    Here are the barrel options I have found: (name, length, threads, and price)
    Faxon 4.5" 1/2-28 $ 109.00
    Adco 4.5" or 5" $ 155.00
    Ballistic Advantage 5.5" 1/2-28 $ 109.00
    Kaw Valley 4.5" 1/2-36 $ 100.00
    KAK 4" 1/2-36 thread $ 80.00
    New Frontier 4" Premium 1/2-36 $ 105.00
    New Frontier 4" Match 1/2-36 $ 135.00
    QC10 3.5" 1/2-28 $ 170.00
    QC10 5.5" 1/2-28 $ 162.00
    Orion 5" 5/8-24 $ 100.00

    And Handguards (name, length, weight, and price)
    GunTec Ultra Lightweight Thin Keymod 4" 6.2 oz $ 46.00
    YHM Mini KR7 4.25" 7.23 oz $ 100.00
    Samson Star-4 Quad Rail 4" 6.0 oz $ 190.00
    Kaw Valley Konza 3.2" 4.98 oz $ 100.00
    Kaw Valley Konza 5" 5.9 oz $ 100.00
    Kaw Valley Carbon Fiber 3.2" 2.87 oz $ 60.00
    Kaw Valley Carbon Fiber 4.625" 3.22 oz $ 60.00
    SLR Solo Intrepid 4", 4.25", 4.5" $ 185.00

    Probably going to just order a Faxon (4.5") and Ballistic Advantage (5.5") then start trying out handguards.
     
  8. Slacker

    Slacker Liquor and Whores...

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    Any 9mm carbine barrel that says "match" is automatically disqualified from my list.
    All that means is the chamber is tight.
    Not a good thing in a 9mm SBR, especially if you reload.

    I have owned a CMMG, Adco, TROS and a QC10. My favorite is the QC10.
    My last pick would be the "match grade" TROS. I had to pay a fun smith to ream it out. Who ever heard of a match grade 5" 9MM SBR?
     
    Last edited: Jul 13, 2017
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  9. MadMardigan

    MadMardigan Antagonist

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  10. JRHorne

    JRHorne Well-Known Member Supporting Member

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    If I could find a dealer to do those transfers for like $50 for all 5, that'd be a deal.

    Never mind, it's out of stock.
     
    Last edited: Jul 14, 2017
  11. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Also found another setup I like that uses a 3.5" barrel and a 3.2" Kaw Valley handguard. I won't go with the PDW collapsible stock, but he says his overall length is 16.5", so using the LWRC I should still be around 20"

    20161129_202953_resized_zpsuv0iccjv.jpg
     
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  12. MadMardigan

    MadMardigan Antagonist

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    I seen this deal and was like, hmmmmmmmm but I already bought a CZ Scorpion lol
     
  13. Zedhound

    Zedhound Guest

    So much want
    upload_2017-7-14_10-50-28.png
     
  14. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Update:
    Received the upper. Looks exactly as expected.
    Also received the lower (Did anyone know Triangle Shooting now charges $40 for a transfer to non-annual members??? Won't be using them again!). Lower looks great and has screws in many places for the LPK.

    Also going to use a BCM PNT trigger in the build. I have a PNT in my BCM build and a LaRue MBT2S currently not in use. Going to swap the LaRue into the BCM and use the BCM in the little guy.

    Finally, I may have ordered a complete 8" upper off M4C... 8" CMMG barrel, 7" Noveske NSR rail with panels and handstop, and VLtor MUR upper. Figured since I am going to SBR the lower anyway, why not go for both the ultimate compact PDW and a nice 8" upper to compliment?

    Pics to come. Complete upper should be here Friday. Need to file my Form 1 in the next week or so.
     
  15. Slacker

    Slacker Liquor and Whores...

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    $40 is steep anyway it's sliced.
    I'm fairly sure our local South Durham NFA dealer gets a good bit less than that.

    Is anything at TSA priced normally or is it all retail + ?
     
    Last edited: Jul 19, 2017
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  16. Zedhound

    Zedhound Guest

    Tsa is rediculous. Products and people
     
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  17. Zedhound

    Zedhound Guest

    My pcc got an upgrade today.
    A sling :p 34 for for the sling and 13 for the mount on the handguard
    IMG_1202.JPG
     
  18. Slacker

    Slacker Liquor and Whores...

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    Is that optic backwards?
    ;)
     
    Last edited: Jul 19, 2017
  19. Zedhound

    Zedhound Guest

    Hardy har
     
  20. Wahoo95

    Wahoo95 Member

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    Nope

    Sent from my SM-N910V using Tapatalk
     
  21. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Hey! Get your own damn thread! You and your backwards optic!
     
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  22. JRHorne

    JRHorne Well-Known Member Supporting Member

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    I'd never buy any product from there. Prices are insane. It's the closest range for me so the $20 an hour is worth it. Oddly enough, the range Marshalls I have encountered are UBER nice. Like unreal. The folks on the retail side... I'm about 1 for 6 nice vs morons. Either way, the only additional money they'll get from me will be range related or if they liquidate their shelves during a going out of business sale.
     
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  23. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Another quick update: With the deal Ballistic Advantage has going on (I posted it in the hot deals section), I placed an order. They also, perfectly, just released a 4.5" 9mm barrel. So I have it coming for this build. I also got the free upper receiver as part of the deal, so between it and the 9mm YHM, I will see which one is a better fit and use it. I'd guess the YHM is going to be fine, but I have to assemble the lower to find out.
     
  24. Toprudder

    Toprudder Be vewy vewy qwiet. Supporting Member

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    The wife and I are members at TSA. We bought several guns from them when they were North Raleigh Guns, but have not bought ANYTHING from them since they opened the range and became TSA. Yes, the prices are outrageous. We only go there to use the range, and eat at the cafe', which is a separate business.

    FYI, if I need a transfer, I go to Carolina Gun Runners. About the same distance from where I live (I'm somewhere in the middle). $25 for me the last time I did it.
     
  25. JRHorne

    JRHorne Well-Known Member Supporting Member

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    I use GunRunners almost exclusively for transfers as well, they've done my last 5 or so. However the place for which I ordered the CMMG had some online FFL lookup that was both crap and didn't have Carolina Gunrunners as a choice. I actually emailed Carolina GunRunners yesterday explaining to them just that and asked that the PLEASE get their info into whatever directory that IowaGun.com is using. I've also seen that look up system on other gun sites too.

    I also did a good bit of business with North Raleigh guns including transfers, changing my Glock sites, etc. It's a much different business now that it is TSA.
     
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  26. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Update: Received the barrel, free upper, Colt LPK, and a few other goodies. BCG, rail, and more on the way.

    Lower:
    Got the lower assembled last night with the Colt LPK and dropped the BCM PNT from my PWS in. Used a DS Arms RE for now just to get everything together. Very pleased with the lower and what I am thinking for the setup. I definitely want a decent ambi selector. I also need some antiwalk pins. I found a deal on the LWRC UCIW stock kit from BuckSniper for less than $100 shipped. Based on my initial measurements with the barrel and short LWRC, I think the whole thing should be under 20" collapsed. Need to get my JP Silent Capture setup.

    Upper:
    Found a used Samson Star-4 4" quad rail that I purchased. Guy is also throwing in a barrel nut for me. That pretty much gives me all of my parts I need.

    Just need to file my paperwork for the lower! I think I will make it a pistol in the interim with a super short pistol buffer tube and maybe a modified KAK blade to keep it short. Pics to follow.
     
  27. Toprudder

    Toprudder Be vewy vewy qwiet. Supporting Member

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    I believe the way the law reads, if you originally assemble the lower into a pistol, then you can later convert it to rifle and back to pistol as you please. If you first assemble it as a rifle, it can only stay a rifle - according to the law. (Stupid laws).
     
  28. JRHorne

    JRHorne Well-Known Member Supporting Member

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    The lower wasn't fully assembled, so within the letter of the law, I'm good.
     
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  29. 11B CIB

    11B CIB Administrator Staff Member Charter Life Member

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  30. JimP42

    JimP42 Mostly harmless Benefactor Charter Life Member

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    My understanding, which is probably flawed, is the the difference is whether the first buffer tube attached is rifle/carbine or pistol tube (if the attached tube is is designed for a stock to attach, it's a long gun). Or at least the first that anyone can document :-/
     
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  31. JRHorne

    JRHorne Well-Known Member Supporting Member

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  32. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Update:

    After reaching out to JP about the Silent Captured spring setup and wanting to use one for the LWRC, I was a little pissed off. The Customer Service guy from JP said he asked his tech and engineer guys and said no setup they offer will work with that stock. I know that is complete bullshit because there are several threads where the 300 blackout guys are using the JP setups. Many of them are taking and modifying existing versions to make them shorter. HOWEVER, JP now makes a setup specifically for the Maxim PDW stock that Zedhound posted above. You can see the JP Silent Captured setup in the picture. Well they also sell the SC setup separately. On Brownell's, I asked the question of how long the product was and they told me 5 5/8". This seems like exactly what I need based on my measurements of the LWRC setup, since the exterior of the buffer tube is 5" long just to the threads. So I will be ordering the SC setup from Lanbo's to try it out. But I can't try it out until I get my form 1 back, which I haven't filed yet because my plan is to file it and at least 2 other lowers at the same time. So I am also going to order the Phase5 Hex-2 pistol tube for the lower in the interim. It's a bit longer but I'm going to use spacers in it to replicate the total interior depth of the LWRC setup and then dial it in.

    Hopefully more updates and pictures to come in the next week or two.
     
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  33. Slacker

    Slacker Liquor and Whores...

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    I have a 9mm JP SCS your welcome to test with.
     
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  34. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Ryan we need to check schedules and let me come out and do some testing. Since you pretty much have it figured out, I'm decently sure we can solve the formula for what I want.
     
  35. Slacker

    Slacker Liquor and Whores...

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    Sounds good.
     
  36. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Long overdue update. I ended up building 3 uppers for this gun: a 4.5" barrel, a 8.5" barrel, and a 16" barrel. I just got the flash hider for the 16" barrel today. Just went with a simple $20 Rousch Sport hider. I can't wait to shoot this configuration, but I need a higher mount for the Aimpoint. Probably get a used ADM or Larue absolute.

    Hopefully everyone saw my write up about the LWRC stock and JP 9mm SCS setup. Love the way it shoots with the 4.5" and 8.5" upper.
    20180203_124802.jpg
     
  37. JRHorne

    JRHorne Well-Known Member Supporting Member

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    I can't believe I forgot to update this thread. So I've shot all 3 uppers now a ton and love them all:

    1: 4.5" barrel is super fun and compact. Whole thing is like 18.5" when the stock is collapsed? Also this barrel length should keep most 147 subsonic. Which is good, because I got my Omega 9K. The bad news is my 3 lug adapter is just a bit too short to allow the can to engage with the rail on it. So I had the damn thing taken apart and was going to order a 5.5" barrel. LAME.

    THEN, I found an extended trilug adapter through In Lead We Trust! ORDERED!: https://inleadwetrust.com/product/hk-style-extended-base-3-lug-suppressor-adapter/

    So I'll get the upper back together tonight and take some pictures of it, then post some more when the tri-lug arrives and I can snug the can up on it. Pics of it with the thread protector below.

    2: 8.5" barrel: my favorite combo to shoot. It's a CMMG barrel with 1/2-36 threads, so I also ordered a tri-lug from ILWT. It has an MRO on the upper and irons and it is just stupid easy to shoot. Lots of fun burning down 32 rounds in a stick at some steel. I am excited to see if the barrel will keep some 147s subsonic or am I going to have to move to a 158, 165, or some hand loads.

    3: 16" barrel, as pictured above. Fun, but with the SBR lower, just totally unnecessary now with the other 2. I will keep it though as it still shoots great and is a lot of fun.

    Also of note, I know there is a lot of hate on direct blowback for the AR9 because of how violent it is. The JP setup on mine has made it both very tame and to the point that I don't need to tune anything when swapping between all 3 lowers. I think that will be the case with the can on as well. Here's the write up on that lower setup: https://www.carolinafirearmsforum.c...us-jp-silent-captured-setup-for-an-ar9.20706/

    Also, I do plan on buying the 5" CMMG radial delayed blowback barrel and BCG combo to build another short upper. However I've reached out to CMMG about it being used with Colt pattern lowers, and they say they can't get it to run reliably. They only sell the 9MM RDB with the Glock pattern lowers. So what I may do is use their version of the Endomag conversion, which converts a regular Pmag to hold 9MM, and try the RDB upper on one of my standard AR SBR lowers.

    So more gun fun to come!

    Here's the 4.5" upper
    20171024_184718.jpg 20171024_184757.jpg
     
  38. JBoyette

    JBoyette Well-Known Member Vendor

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    Thats nice.

    For me and these kind of builds i like the MOE fixed carbine stock fyi.
     
  39. JRHorne

    JRHorne Well-Known Member Supporting Member

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    Yea I've seen those and I also have the Ace Fixed on another carbine lower that I like, but this is even more compact and is adjustable.
     
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  40. JBoyette

    JBoyette Well-Known Member Vendor

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    Totally agree.

    The fixed MOE is 2 clicks out.

    Added to a Law folder its its equal to A1 OAL fyi....

    I love your shorty