AR47 Build on GWACS Armory CAV-15 MKII Lower

[Emptymag]

APOC Armory BCG came in. That's the last gun part I needed.

I guess I'd better get my ass moving on installing the LPK and get to ordering a mag or two!

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Still need to install the LPK, but I ordered a few C Product Defense 28 rd mags from North River Distributors LLC at 2am and they sent a shipping notice this morning!

I guess I'd better get crackin' on that lower parts kit install!

[Emptymag]

I believe I was asking about buffer weights earlier in this thread - wondering what I should use.

Since I'm about to start installing the LPK and there are some minor differences in doing so vs a standard lower, I started reading some of the detailed info regarding these CAV15 lowers. Glad I caught this...

Calibers larger than .223 will require 3H or heavier buffers. Unlocked blowback pistol caliber uppers must use appropriate weights (9mm 5.5oz, .45 8 oz. Or heavier to avoid damaging the lower)

I guess I need to figure out what a "3H" buffer is and order one.
I know my pistol has a "heavy" buffer in it that I could try, but I have no idea what the weight is - it just said "heavy" on the description when ordered.

[Emptymag]

Two days later and...

A few 28 round C Products Defense 7.62x39 AR15 mags arrived today.

They're a bit less dorky looking than the 30 rd 7.62x39 mags (shorter, less pronounced curve)
Too bad they aren't dirt cheap like 5.56 mags. Gonna take a long time to stockpile these bastards at $19 each!













Compared to a 5.56 USGI 30 rd mag...

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Lower parts kit installed tonight!

I used an Anderson LPK with stainless steel trigger/hammer - but I didn't use their trigger/hammer - I used an ALG Defense ACT trigger.
(I also have a KE Arms LPK so I opened up both to compare and the Anderson parts looked "better" overall)

I used this video which is very thorough and I did have to make two modifications as mentioned may be necessary in the video.
The safety/selector detent would not drop into the hole and it is mentioned in written instructions that the base of the detent may be too large and to either cut off, or file it until it fits - I filed around it and it worked.
I also needed to cut two coils off the bolt catch spring so the bolt catch buffer would sit lower. Easy peasy.
My "roll pin punch" for this project was a 1/8" hex key - worked great!

Posted before, but worth posting again for anyone who may be working with one of these lowers...



Technically speaking, this puppy is ready to throw lead downrange.
Gonna test it on Sunday and play with the adjustable gas block and get that set. Woo-hoo!

[Emptymag]

Here's the APOC Armory black nitride 7.62x39 BCG mfg link
Purchased from ar15discounts.com

• 7.62x39
• Full Auto Capable
• 9310 MPI and HPT Tested bBolt
• Case Hardened 8620 Carrier
• 4130 Gas Key
• Grade 8 Hardware With Proper Staking
• Gas Key Sealed With Permatex No.3
• 8740 Hard Chrome Firing Pin
• Black Nitride Treated For Reduced Friction And Increased Longevity
• Proudly Made In The U.S.A (manufactured by TOOLCRAFT Marion, North Carolina)
• Unconditional Lifetime Warranty

It almost looks like the staking isn't touching anything, but I tried slipping a piece of paper in there and it won't fit - the metal is touching.

[Emptymag]

COMPLETE and FUNCTIONAL - mostly.

I met up with Nate7667 today to get my other upper assembled and when that was done he helped me adjust the gas block on this carbine.

The gas adjustment portion seems OK, but we were getting random rounds that would not fire.
The primers were dented. It was Tula, Wolf, and Golden Tiger - all steel case.

I know the APOC Armory BCG is supposed to have the "enhanced" (longer) firing pin that almost everyone now uses in 7.62x39 bolts now.
As far as I can recall, and as was suggested by Nate, a heavier hammer spring may be needed.

The trigger is an ALG Defense ACT trigger.
I currently have a standard 3oz carbine buffer in it.
Seekins Precision adjustable gas block.
I do not have the buffer retainer installed - the buffer/spring is just held in by closing the upper. I doubt that has any bearing on the problem.


USMC3531 is going to bring me a spring to the group shoot next weekend so I'll be able to test it again then.

[Emptymag]

More pics.
(I just noticed that the handguard needs adjusted. It was removed to facilitate adjustment of the gas block and didn't get pushed back all the way before tightening it up when it was reinstalled)

I think the 28 rd mags look good.






I added an Odin Works XMR extended mag release. I like this original version better than the V2 I used on my 9mm and I think the brand new V3 model is more for looks than function, so I stuck with the old style.

Also note in this pic the hole for the hammer pin - it appears that the pin is not properly positioned, but that's just one of the few differences between the CAV-15 lower and a standard lower. The pin is in place correctly - it's just that the wall of the lower is thicker externally in that area. (I assume for added strength)










Do you see that little "pinhole" in the lower just to the rear of the takedown pin?
That's where a long, thin roll pin goes in. It's what holds the buffer retainer in since there isn't a standard buffer tube to hold it in place.
I actually omitted the buffer retainer on this rifle, but put it in the other (lightweight) build, so this one has no buffer retainer - when I open the upper from the lower I just need to remember to catch the buffer so it doesn't go flying.

[Nate7667]

Geeeeeeze....they let anyone run an allen wrench

[Emptymag]

Geeeeeeze....they let anyone run an allen wrench

This is what happens when you don't check for current certifications.

Tough life lesson.