Grand Power Stribog 922(r) Worksheet

[LESchwartz]

(Click to expand)

	Part	Plan #1	Plan #2	Plan #3	Plan #4	Remarks
1	Frames	Imported	Imported	Imported	Imported	Item #5
2	Barrels	Imported	Imported	Imported	Imported	Item #4
3	Barrel Extensions	Not Applicable	Not Applicable	Not Applicable	Not Applicable	Required for NFA purposes.
4	Mounting Blocks	Imported	Imported	Imported	Imported	Item #27 or #28
5	Muzzle Attachments	Imported	Imported	Made In USA	Imported	Item #46.1
6	Bolts	Imported	Imported	Imported	Imported	Item #3
7	Bolt Carriers	Imported	Imported	Made In USA	Imported	Item #25
8	Operating Rods	Not Applicable	Not Applicable	Not Applicable	Not Applicable
9	Gas Pistons	Not Applicable	Not Applicable	Not Applicable	Not Applicable
10	Trigger Housings	Made In USA	Imported	Imported	Imported	Item #13
11	Triggers	Made In USA	Made In USA	Made In USA	Made In USA	Item #6
12	Hammers	Made In USA	Made In USA	Made In USA	Made In USA	Item #7
13	Sears	Not Applicable	Not Applicable	Not Applicable	Not Applicable
14	Disconnector	Made In USA	Made In USA	Made In USA	Made In USA	Item #9
15	Buttstocks	Imported	Imported	Imported	Imported	Not pictured
16	Pistol Grips	Made In USA	Imported	Imported	Imported	Item #1
17	Forearm handguards	Not Applicable	Not Applicable	Not Applicable	Not Applicable
18	Magazine Bodies	Imported	Made In USA	Imported	Imported	Not pictured
19	Magazine Followers	Imported	Made In USA	Imported	Made In USA	Not pictured
20	Magazine Floorplates	Imported	Made In USA	Imported	Made In USA	Not pictured
	15 Imported Parts	10 Imported Parts	9 Imported Parts	10 Imported Parts	10 Imported Parts

I'm going to be adding a barrel extension & stock to my Grand Power Stribog "pistol" in order to convert it into a rifle.  Unfortunately, that means I will need to play the 922(r) compliance "10-or-less game".  I would like folks to weight in on my parts counting above.  Here are some notes:

1)  Item #1 on the drawing might be categorized as either a pistol grip or frame.  I went with pistol grip, but in either case it's clearly a counted part.  I also counted it as a single part.  There is a outside chance ATF might count it as two parts.

2)  Item #5 on the drawing might be categorized as either a frame or handguard.  I went with frame, but in either case it's clearly a counted part.

3)  Item #13 on the drawing might be categorized as either a trigger housing or frame.  I went with trigger housing, but in either case it's clearly a counted part.

4)  Items #18, #19, #20 comprise the magazine assembly.  There are 3D printed inserts available which allow the OE Stribog lower to use Colt 9mm SMG magazines which are US-made by several manufacturers.

5)  Items #11, #12, #14 comprise the Fire Control Group (FCG).  Note that Plan #1 either removes or replaces Item #13.  If you use a "drop in" AR FCG, it will be replaced and is thus maked "Made in USA" for Plan #1.  If you use a mil-spec style trigger it will be removed, so it is not included in your imported parts count anyway.  The second method retains this part while using a non-drop-in US-made FCG.

6)  Item #25 is the bolt carrier.  HB Industries sells Non-Reciprocating Charge Handle Conversion Kits which include US-made bolt carriers.

7)  The OE Stribog does not include a barrel extension.  If you use one (permanently attached) to extend the barrel 16", it does not reduce your imported parts count.

8 ) The OE muzzle nut is likely a counted part.


Compliance Plan #1 is to use a Lingle Industries aluminum lower along with a US-Made AR FCG and pistol grip.  That should switch out the five imported parts I need.  Lingle makes lowers which allow the Stribog to take a variety of magazines.  I chose to use the OE Stribog mags -- which have no US-made equivalents at this time.  I know I could have used either a CZ Scorpion or Glock compatible lower along with US-made magazines, but I already look to be at ten or less parts.  Besides, I'm already heavily into OE Stribog mags.  Note that the Lingle lower and pistol grip replaces the entirety of Item #1, so your safe even if ATF counts it as two parts.

Compliance Plan #2 is to use an "RC4 Stribog Colt Magazine Adapter" and purchase replacement US-made Colt 9mm magazines.  In addition, you swap the FCG for an AR FCG.  The LaRue FCG seems close to a "drop in" solution.  Mil-spec FCGs require some serious gunsmithing.  Note that in any case, the hammer width must be less than 0.270".  This should also switch out the six imported parts you need, giving you a margin of safety on the parts count.  NOTE:  I could not get this option to cycle hollow points reliably.  I didn't try ball ammo.

Compliance Plan #3 is to use an a US-Made AR FCG, muzzle attachment and HB Industries bolt carrier.  The LaRue FCG seems close to a "drop in" solution.  Mil-spec FCGs require some serious gunsmithing.  This should also switch out the minimum of 5 imported parts you need.

Compliance Plan #4 is to use a US-Made AR FCG, magazine follower, and magazine floorplate.  The LaRue FCG seems close to a "drop in" solution.  Mil-spec FCGs require some serious gunsmithing.  Note that in any case, the hammer width must be less than 0.270".  This should also switch out the minimum of 5 imported parts you need.  Unfortunately, US-made magazines, magazine followers, and magazine floorplates are not yet available.

If you're concerned that I might have miscounted in some way, you can swap additional parts:  Muzzle attachment, buttstock, or bolt carrier, etc.  As always you're responsible to ensure your comfortable with modifications you perform to your firearms.  As they say, "your mileage may vary".

Comments?

Larry

[LESchwartz]

I just happen to have a brace which is now classified as a stock should I add it to my pistol.  I found this site:  https://www.dirtyjdesigns.com/collections/for-sb-tactical-braces.  They sell "plugs" for pistol braces, which help your brace to be more like the stock ATF thinks it is.

Larry

[LESchwartz]

Notes on Compliance Plan #2:

AR triggers are slightly narrower that the OE Stribog trigger.  They require 20 thousandths worth of shims on each side of the hammer and trigger.  After some amount of cursing at the shims, I got one of my LaRue triggers mounted in the OE trigger housing (item #13). Unfortunately, the trigger binds when installed in the lower. It's almost like the trigger slot isn't long enough.

I opened up the front of the trigger slot in the lower. I had to take quite a bit of material off the front of the slot (about 1/8"). The front of the slot can limit the pre-travel of the trigger, making it unsafe. There is also some sort of circular "stop" at the bottom of the lower which can limit the over-travel -- I took this down some as well. Since installing the safety is kind of a pain, I toke off more than absolutely required. I would recommend anyone attempting this install to have some amount of gunsmithing skill, as you could easily end up in an unsafe condition if you're not careful. YMMV!

I was nervous before I opening up the trigger slot on my lower: Several other folks have mentioned that the rear of the mil-spec AR trigger needs modification in order for the safety to work correctly. I certainly didn't want to modify my lower, only to find out the safety wouldn't work. However my preliminary testing looked positive, so I went forward. In the end, the LeRue seems to work just fine with the HB safety I have installed in my lower.

I think I'm going to order "RC4 Stribog Colt Magazine Adapter" and some Colt 9mm magazines. If my testing goes well, I'll have a second complete lower ready to go. My plan is to hang onto it in case I decide to purchase an SP9A3 as a stablemate for my SP9A1.

Larry

PS:  Here's a link to a supplier for the shims.  You'll want to order the ones which are 0.02" thick (20 thousandths):  https://www.mcmaster.com/93574A200/.

PPS:  Here's a link to a post on installing mil-spec AR triggers on the Stribog:  https://www.ar15.com/forums/Armory/STRIBOG-SP9A1-and-SP9A3/48-490394/?page=30.

[LESchwartz]

Unfortunately the "adapter conversion" using the OE lower, LaRue trigger and Brownells branded Colt SMG magazines did not work at all. It seemed like the LRBHO would not disengage.  I spent some time with some snap caps and notice that the Colt magazine's follower looks to activate the BHO cycling the second to the last round.  When I ordered the adapter, I also ordered some of the followers sold along with them.  Those followers seem to hand cycle 20 rounds flawlessly through to empty.  Unfortunately, I could get every other shot to feed correctly using hollow points at the range (I didn't try round nose).

I noticed the mags seemed awful sloppy in the mag well. I imagine that was some of the problem.  Another vendor sells an adapter with "built in feed ramps nudge the rounds inward and up just enough to hit the barrel feed ramp correctly."  Unfortunately, I am not a fan of plastic feed ramps, so I can only judge the adapter conversion as appropriate for ball ammo at best.  So we're still in YMMV territory here.

Hopefully somebody will make USA followers and/or floorplates for the OE Stribog mags before too long.

Larry