Broken Arms » BK-308 compatible parts list.

Mike · 7/06/2016 7:20 pm

I'm trying to compile a list of parts that will, and wont work with our 308 lower. Ill update as I get more info.
Any info that you guys have would be greatly appreciated.

If youre building a Broken Arms 308. Everything in the AR-15 lower parts kit will work perfectly. EXCEPT these 3 items.
1) front pivot pin
2) rear takedown pin
3) bolt catch

Part dimensions:
-308 front pivot pin length (from bottom of head to end of pin)
DPMS - 1.520     <--- works perfectly
Aero - 1.590     <--- works, but a little long
Palmetto - 1.350     <--- too short

-308 rear take-down pin length (from bottom of head to end of pin)
DPMS - 1.070 <---- works perfectly
Aero - 1.070     <--- works perfectly
Palmetto - .700 <--- does not work. too short

-308 bolt catch (from center of hole, to right side)
Aero - .945 <--- works perfectly
Palmetto - .998     <--- too long. will not work
(palmetto has a saw cut on right side. not sure if this number varies)

- 308 upper receiver ( DPMS style)
Aero M5 upper     <---- fits perfectly and looks best (our lower was designed to match up to it)
Palmetto PA10 upper     <--- does not fit. (Palmetto upper doesn't match any. They are proprietary to Palmetto)

PLEASE POST IF YOU SEE ANYTHING INCORRECT!!!

Last edited by Mike (3/26/2019 2:33 pm)

rich_o · 7/14/2016 4:34 pm

Hi Mike,
This list is very helpful to know some things to expect in a 308 build.
Due to the environment in our "great" state, I am considering building my 308 as non-semi-automatic using a side cocking upper and a plugged gas block. I was considering using the Fulton Armory "Upper Receiver & BCG, Titan .308, Flat Top, Side Cocking, DPMS Pattern".

It is here:
****looks like I can't include the link since it is my first post***

They don't state if it is high or low profile DPMS and I don't know if it is possible to tell from the image. From what I have read, the difference is only in the height of the rail above the receiver, but I don't know if that is totally true. If so it seems like it shouldn't affect the fit to the lower.

It would be great to know if anybody here has had experience with this or any Fulton DPMS pattern 308 upper.

smalo7 · 8/09/2016 11:24 am

The only problem I had with my Fulton Armory "Upper Receiver & BCG, Titan .308, Flat Top, semi-auto, DPMS Pattern" was FTF with Magpul Gen2 20 round mags (cycled singles fine). No problems with USGI style mags. I'm going to try an Armalite AR10 mag catch & see if that clears the fail to feed with the Magpul mags. Nice upper on a sweet BA lower!

cshs · 1/19/2017 7:44 pm

Just finished my 308 build. Aeroprecision upper/BCG, Aeroprecision standard LPK, Timney trigger.

Few notes:
-Yes the AP front takedown pin is too long, grind it down before you put it in, doesn't want to come out like an AR-15.
-The AP mag release button is twice as thick as a standard AR button. This will prevent screwing in the bolt as far as you want. Need to replace that part (Maybe $1, if you don't have one in spare kit).
-The rear takedown pin comes in vertically in a hole just aft of the safety detent/spring hole (not horizontally from the back like the AR-15) You need to drill a small hole in the handgrip for the rear takedown pin spring to rest.
-So far, mine wont feed with Magpul mags, DPMS mags ok. This is bench testing only. I'll let you know after I fire it.

Last edited by cshs (1/19/2017 7:45 pm)

cshs · 1/26/2017 10:41 pm

Took it to the range, some feeding issues initially with all mags. After 20 or so rounds I seemed to have broken it in. Emptied the last mag of 10 in rapid fire, no problem. Gun shoots great. After it was running good, I added an Aeroprecision muzzle brake. Never used one before. Noticeable reduction in recoil. Highly recommend it.

Bullseyebishop · 1/31/2017 9:20 pm

Cool, I was trying to find a list!

cshs · 2/19/2017 6:44 pm

Range report #2. No problems still with magpul mags, but DPMS mags still have problems. Clean it good after use, the BCG parts get pretty fouled and tighten it up. .

JabberWoggy · 11/12/2017 4:24 pm

Has anyone tried an FTF Industries "DPMS type" SR25 upper assembly?
https://www.ftfindustries.com/product/AR-10UP.html

Broken Arms · 12/08/2017 12:11 am

JabberWoggy wrote:
Has anyone tried an FTF Industries "DPMS type" SR25 upper assembly?
https://www.ftfindustries.com/product/AR-10UP.html

Thats an Aero M5 upper. It fits perfectly with our 308 lower.

Also, I dont think thats SR25. Its DPMS style. Same one as we sell on the site.

Jason · 2/18/2018 6:44 pm

Glad I found this. I really like the looks of the 308 80 percent lower BA has.

Has anyone used the CMMG lower parts kit? I am looking at kits without the grip/safety selector/trigger as I am sourcing those from other companies.

Thanks ahead of time.

Jason

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» BK-308 compatible parts list.

7/06/2016 7:20 pm #1

BK-308 compatible parts list.

7/14/2016 4:34 pm #2

Re: BK-308 compatible parts list.

8/09/2016 11:24 am #3

Re: BK-308 compatible parts list.

1/19/2017 7:44 pm #4

Re: BK-308 compatible parts list.

1/26/2017 10:41 pm #5

Re: BK-308 compatible parts list.

1/31/2017 9:20 pm #6

Re: BK-308 compatible parts list.

2/19/2017 6:44 pm #7

Re: BK-308 compatible parts list.

11/12/2017 4:24 pm #8

Re: BK-308 compatible parts list.

12/08/2017 12:11 am #9

Re: BK-308 compatible parts list.

JabberWoggy wrote:

2/18/2018 6:44 pm #10

Re: BK-308 compatible parts list.

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» BK-308 compatible parts list.

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