Looking to Build AR9. What Features and Manufactures to Consider?

[Michael303]

I'm interested in building an AR-9 style PCC.  I have a few questions I'm hoping to get some feedback on to jumpstart my research. 

 

What features are nice or must have, particularly for USPSA?  For instance, I gather that last round lock back is fairly common and useful but not necessarily a feature every PCC has.  Are there other similar features I should look for?

 

Do most of the uppers and lowers take mil spec AR parts other than bolt, barrel, and mag release?  Without knowing more my thought is that would be the preference since there are so many options out there versus proprietary parts.

 

My preference would be for it to use Glock style mags since I have quite a few already and they're cheap.  Is there another option that significantly outweighs this?

 

Lastly, for lowers and uppers, I've been looking at Angstadt, Foxtrot Mike, Primary Weapons Systems, and Rainer Arms.  Are there other manufactures I should take a look at?  What makes any of them stand out?

 

Any feedback is appreciated.

[Darqusoull13]

35 minutes ago, Michael303 said:

I'm interested in building an AR-9 style PCC.  I have a few questions I'm hoping to get some feedback on to jumpstart my research. 

 

What features are nice or must have, particularly for USPSA?  For instance, I gather that last round lock back is fairly common and useful but not necessarily a feature every PCC has.  Are there other similar features I should look for?

Quality parts that go together as a system are key. 1 malfunction and you're down a minimum of 20% on a stage. 
A trigger (JP) that's been proven to run in blow back systems, a short stroke buffer to speed up the cycle (JP SCS) , quality barrel with a long throat to run anything you want (JP), a comp, a giant gaping magwell (Taylor Freelance) and base pads to get you to ~40+ rounds for USPSA or 50+ for outlaw/multigun (TF, MBX, TTI). 

Do most of the uppers and lowers take mil spec AR parts other than bolt, barrel, and mag release?  Without knowing more my thought is that would be the preference since there are so many options out there versus proprietary parts.

Most lower will be mil-spec-ish with the exception of the mag release, mag catch, magwell, ejector etc which are obviously set up for GLOCK mags. You can build a PCC out of a milspec upper. Some of the billet uppers have a different ejection port and brass deflector but I haven't had issues starting with a standard stripped upper. 

My preference would be for it to use Glock style mags since I have quite a few already and they're cheap.  Is there another option that significantly outweighs this?

GLOCK-brand-GLOCK mags are 100% the standard. There are a metric ton of options for base pads and the GLOCK design is proven. 

Lastly, for lowers and uppers, I've been looking at Angstadt, Foxtrot Mike, Primary Weapons Systems, and Rainer Arms.  Are there other manufactures I should take a look at?  What makes any of them stand out?

Look at the JP. My first build had mostly JP parts and now ..uh, 6ish personal builds in I just end up ordering complete guns. 

Any feedback is appreciated.

 

[Michael303]

Hey, thanks for the feedback.  When you reference parts-as-a-system are we talking nearly complete guns minus furniture or is it more a few key parts?

[Bwillis]

Upper and lower

effff Juan (F1)

qc10 

iron city 

 

barrels 

shooting innovations 

mbx 

 

comps 

coda 

american precision 

 

bolt 

iron city (they are cut for shooting innovations ramp barrel)

 

buffer

mbx

blitzkrieg

 

lpk

i bought cmmg

 

Most non magazine/ammo related malfunctions I’ve seen have come from foxtrot mike lowers paired with a cheap upper. 

 

Building a pcc you’re going to get malfunctions to start like darq says but there is always a remedy. Playing with different ends of the tolerance spectrums can be problematic. 

 

Edited June 19, 2019 by Bwillis

[Mark Meyers]

I used a foxtrot Mike lower with Taccom complete upper using their extreme feed 14.5 barrel.  Also used taccom 3 stage buffer.  Added a hiperfire trigger.  This thing hasn't had a single malfunction with approx 1500 rounds fired.  I'd put it up against any other gun out there.  One note, Taccom will be releasing a delayed blowback buffer system shortly.  It sounds like it's worth waiting for.

[Mark Meyers]

Forgot to mention there's one small issue when using FM lower with Taccom.  There is a small "hook" on the lower that activates their bolt hold open.  It touches a corner of the feed ramp on Taccom barrel.  Easy fix is to take dremel and cut off hook.  I don't use BHO, so it wasn't an issue for me.  Other option is to relieve corner of feed ramp.  If you're not comfortable with these, any quality lower will do.  Possibly QC10?  Also highly recommend hiperfire trigger and Holosun optic.

[Darqusoull13]

18 hours ago, Michael303 said:

Hey, thanks for the feedback.  When you reference parts-as-a-system are we talking nearly complete guns minus furniture or is it more a few key parts?

Basically what folks responded as follow ups. When you build with mix and match parts you can end up getting issues with parts that are not compatible or just plain don't work well together. I don't have the patience to buy something then immediately start Dremeling it to get it to work. I like buying something that is utterly reliable and focusing on getting better with the tool. Nothing ruins getting into a division like s#!t breaking all the time. 

On the flip side when you buy reliability you're really just trading the cost of ammo for a huge grin every time you pull the trigger.

[cecil]

Taccom ULW with 5-1/4" barrel complete upper … Quarter Circle Lower... Hiper Fire competition trigger... Blitzkrieg hydraulic buffer with .223 carbine spring  ...  Holosun 520C red dot scope...  this combo runs 100% 

[3GN]

Buy once, cry once ....JP parts