PCC 9 MM build (AAR)

[pfcchambers]

I thought I would share some on the information I have learned in putting together a few AR-9s. Full disclaimer I am no gunsmith and a mostly unskilled shooter who shoots for fun purposes only, any information here is simply my opinion take it as you will. When starting out and wanting to get into PCC, cost was the first thing I considered. Second, was the fact that I am most familiar with the AR platform and liked the fact I had many options to set them up how I wanted. I do think the MPX and Scorpion are awesome and if funds were not an issue I would own one of both. One aspect that concerned me going with the AR in 9 mm was reliability. I have no plan to use this for anything else other than gaming so no thought went into "tactical concerns". I also personally did not want to deal with the legalities and cost of SBRs or silencers, a 16-inch carbine was always my intent. I have so far completed two PCC in 9 mm. One to get me started in PCC and one for as Xmas/B-Day for my father. I have also acquired most of the parts two build me a backup gun to have at matches but to date still need a barrel, Charging handle, and trigger group. 

I was in somewhat of a hurry to get one before certain events that may be happening this coming November cause an increase in price or firearm/parts availability issues. I started looking to find the required parts and did find myself limited on what was available so the parts used in my builds may have been slightly different had all options been available. 

Magazine style -I choose to go with Glock magazines due to their reliable reputation and ease of finding magazines. I do not own a Glock pistol so whether I choose Glock or Colt style I would have had to buy magazines. At the time of ordering my lowers, PSA had a sale on 10 ETS Glock magazines, which brought their cost down to around 15 dollars per mag. At one point in time it sounds like some of the Colt style magazines were a bit finicky but from what I have read most seem to have good luck with them now. The angle of loading the magazine is the only one reason looking back I would re-think the Glock lower. However, I do not find reloads with the Glock lower to be too hard and honestly, I could go either way on which style to use if I was to do it over again. If you already own Glock, mags go with what you are able to get.

Lower- I was able to catch some stripped Palmetto State 9 mm Glock dedicated lowers in stock and ordered two. I did not want to use a magazine conversion I had decided I wanted a dedicated lower. Based on a little internet research these lowers appear to be made by New Frontier Armory for Palmetto. This style of lower does not have a last round bolt hold open. The lowers I received had some slight color deformities but nothing I was worried about I am going to be dumping the gun into a barrel after all. The lowers have some nice little touches I liked. Instead of using roll pins, it has threaded screws. No deal breaker but it was a nice touch when putting the lower together. In addition, they come with an oversized integral trigger guard. Fairly certain New Frontier makes them for PSA, and Joe Bob's Spartan 9 mm lowers, So probably not going to be many differences, pick whatever one you get the best deal on.

Upper- This was the hardest part to source when I was ordering. I initially was not going to go with  a side charger upper. My 3-gun set ups are traditional charging handle and wanted to keep similar feel. However when looking for an upper I initially wanted to go with New Frontier Armory's slick slide upper with LRBHO. I could not however find any in stock anywhere and I guess I am inpatient. So I went with what I could source which happened to be a 9 mm slick side upper by Spinta Precision. The second upper I decided to try was a Matrix Arms side charger due to the fact it was in stock and was actually more economical when I priced in not having to buy a charging handle. (If you run a plain jane charging handle it would be cheaper but I knew I was going to buy a nice ambi, oversized option). So far I am really liking the Matrix arms side charger and would buy another. I went with the Matrix arms for my father’s PCC.  I have not finished the PCC using the Spinta upper yet as my charging handle I ordered, the new Geisslle Super charging handle is on back order. I chose this one as it supposedly has a lip on the back end of the charging handle that helps with blow back. Based on what I know now, I would buy whatever is available first, second decide if you want traditional charging handle or side charging, and third if you must have LRBHO feature. 

Bolt - From what I gather the BCG and buffer is the heart of the 9 mm AR platform and I did not want to skimp on this aspect of the build. In deciding on a bolt I was not able to find a ton of information as to sell me on any one particular brand. Based on my lower/magazine choice the BCG needed to be already cut for Glock magazines. Most BCGs being sold today work with both Glock and Colt style magazines. The PSA Hybrid bolt, JP Enterprises, Spinta Precision, Kaw Valley Precision and New Frontier Armory offerings all are made to work with Glock or Colt style magazines.

Spinta Precision BCG - This is the first BCG I ordered. It was the cheapest as well. It comes with a nice QPQ finish, machining was also top notch. Full disclosure I did have to send it back to Spinta Precision due to the fact the hole for the roll pin holding the extractor was oversized. First outing the extractor fell out and bent ending my range time. Spinta was great to work with and ended up just replacing the whole BCG, they had first class customer service. In addition, I know have no concerns over their products, if you have an issue they will take care of you.

JP Enterprises BCG- As I am sure anyone belonging to this forum knows JP is top notch and you probably cannot do much better. I ordered this BCG because I wanted to see the difference between this and my Spinta. After receiving it, quality is of course top notch, however the only gripe about the JP is the plain phosphate finish is not as nice as the QPQ you get on the KVP or Spinta. Cost was the most expensive to the tune of around $100 dollars more than the Spinta and KVP. 

Kaw Valley Precision BCG - When ordering my the barrel for my father’s build I saw KVP was now offering a BCG and figured since it was only 10 dollars more than the Spinta I would give it a shot. The KVP BCG looks great, QPQ finish, great machining. If I was to remove the KVP logo  I would not be able to tell the difference between this BCG and the Spinta. 

Overall- the Spinta and KVP are so close in all aspects pick whatever one you can get. The JP is well a JP. If you have the cash and want a JP BCG, get it. So far, they are all working well.

I weighed all three of my BCGs these are my results.

Spinta BCG Weight - 15.55 oz. with rear weight. (12.19 oz. with weight removed set up for JP SCS)

KVP BCG Weight - 15.52 oz. with rear weight (12.16 oz. with weight removed set up for JP SCS)

JP BCG Weight - 13.55 oz. (The JP does not have a removable weight)

Buffer System - As stated above the BCG and buffer system seem to be the most crucial aspect in the AR 9 mm platform. I bought Kaw Valley Precision's PCC kit they sell with the included extra heavy spring, proper length buffer and tube. I also bought a JP gen 2 9 MM silent captured spring. Right now I am currently slightly preferring the JP SCS. Mostly due the fact is really smoothed out the action. Reliability is a tie between the two. More testing will be needed between the two before I would make any definitive recommendation. I am also running the JP SCS with the JP Bolt, I have not done enough testing yet to compare the Spinta or KVP BCG with the JP SCS. 

Buffer Weights 

 

JP SCS Gen 2 9MM - 8.56 oz

Kaw Valley Precision - 7.55 oz

Total Weight Combo's

 

JP BCG + JP SCS = 22.11 oz 

Spinta BCG + KVP Buffer = 23.1 oz 

Spnta BCG + JP SCS = 20.75 oz

KVP BCG + KVP Buffer = 23.07 oz 

KVP BCG + JP SCS = 20.72 oz

Trigger - Triggers in the AR 9 mm platform seem to vary greatly in what works. All of the BCGs I bought are cut to work with AR-15 style hammer and do not require a 9 mm specific. My limited research led to the thinking that for utter reliability it was best to stick with a mil-spec trigger group. In my 3-gun rifles, I run Velocity 3 lb. flat triggers. I find these to be an exceptional trigger. They per Velocity are not recommended for any blow back guns so I needed to find another option. I decided due to cost to try the ALG ACT trigger and threw in a JP reduced power spring kit. This set up has been 100% with all BCGs and I do like it. Later I might get something else however simply because I one really like my flat triggers and my 3 lb. flat triggers. If I decide to get something else it will most likely be a POF flat trigger. (If anyone has tried the POF flat trigger in an AR-9 and has had, good results let me know.)

Handguard – Pick whatever one you like. I tried out the Kaw Valley Konza rail on one build, went with a Faxon on the other, the third is undecided. One thing to consider is on both Matrix arms and Spinta both handguards took some filling and modifying to get them to fit the non mil-spec uppers. The Konza took far less modification than the Faxon. However, I much prefer the mounting system the Faxon uses to the Konza. So pick your poison.

Barrel – As stated above I had no desire to do a SBR or run a silencer. A 16-inch carbine was what I was after. Most AR 9 barrels I looked had 1:10 rifling with 1/2X36 threads. I am a fan of Faxon Firearms who also makes the KVP Barrels. One barrel I went with KVP 16 inch, the other was the Faxon branded barrel. The KVP was 10 dollars cheaper. So far, they both offer very good accuracy and if I notice any perceivable difference, I will report later.

Compensator – In a 16 inch, 9 mm blowback rifle a comp is probably a waste of money. But both barrels were threaded 1/2x36 and I was definitely not going to waste money on a bird cage or thread protector that I know for a fact would do nothing to mitigate recoil so I bought a comps. The first one I bought from Joe Bob’s was a JP 9 mm comp. It is the style no longer offered by JP. The second and third Comp I purchased was from AP Manufacturing. The AP compensator looks almost identical to the JP and was only $30 to the JP’s $65; the AP also included a jam nut, which I am a fan of. My recommendation would be to check out the AP comp: cheap, looks good, and if anything adds some weight to the end of your barrel.

Optic – I decided on the New Vortex Prism AR. I figured USPSA would all be close and quick and 3- gun the farthest my 9 mm would be any good for would be 100 yards or so. Still waiting on the Prism to show up, running a TRS-25 I took of another rifle until the Vortex arrives.

Summary – Overall, I have learned a ton in putting together a few PCCs. The guns shoot well so far and I am happy with the overall outcome. If I ever decided, I do not want it I do not think I would lose any money selling it. I will continue to try some different BCG and Buffer combos as well as ammo to see what feels the best to me. Surprisingly my little PCC has more felt recoil than both of my tuned .223 guns do, but it is still very little I mean it is a 9 mm. The cost of feeding the 9 mm for me is half of what .223 would be. I am looking forward to playing with it in both USPSA and 3-gun.

 

 

 

 

 

 

 

 

Edited October 11, 2016 by pfcchambers
adding pics

[TXMXRACER]

Great info. Thanks

[JRM83]

That build with the Konza rail on it is pretty close to what I am looking at assembling. What is the unloaded weight on it?

[pfcchambers]

18 minutes ago, JRM83 said:

That build with the Konza rail on it is pretty close to what I am looking at assembling. What is the unloaded weight on it?

To be honest I have not weighed the rifle as a whole. I have never mined a heavier rifle. It was built with no regards to being light weight. 

[wgj3]

I think this was a fantastic write-up. I'm sure that I speak for a few other folk on here when I say, thanks for taking the time to do this.

[pfcchambers]

2 hours ago, JRM83 said:

That build with the Konza rail on it is pretty close to what I am looking at assembling. What is the unloaded weight on it?

To be honest I have not weighed the rifle as a whole. I have never mined a heavier rifle. It was built with no regards to being light weight. 

[pfcchambers]

No problem, I am far from an eloquent writer and not very techy so excuse my rambling on and poor quality cell phone pics. There just does not seem to be as much info out there on PCCs yet so I figured I would share some of what I learned. It will be exciting to see how far PCCs will develop if they get popular enough. 

[Marshal82]

Pretty much the same 2 builds I'm testing. One a Mostly JP rifle minus the upper and rail. The second a "budget" Gun with Spinta/KVP Bolt, faxon barrel, NFA Lower and plain slick side upper. I'm reviewing for my website and have the first article posted about my initial thoughts. 

[JRM83]

Thanks for the write-up and all the information. I just ordered the parts for a near identical build. 

[Les Snyder]

just a comment on building a PCC, something I overlooked... I've built several AR style rifles and pistols with a DI locking bolt, and never gave any thought to head space...never had a problem, even mixing bolt carrier groups...I ran some heavy buffers/bolt and spring combinations in my 9mm PCC, and after a 250 round match with a 22.5oz and .308 spring noticed some battering of the barrel breech face, so switched to a lighter system... I perceive that the chamber depth was possibly too deep

 

before you assemble your PCC, I would suggest you make a dummy round, hand insert it under the extractor and slide it with bolt attached into the chamber until you are sure it seats... you should have a little head space (I was told .005" by a machinist on another forum)... too much head space, and the heavy bolt/spring combo will try to seat it past the chamber shoulder and jack up pressure... too little will allow the bolt to hit the barrel...we are asking the cartridge shoulder to stop a force that occasionally breaks last round bolt hold open systems

something to look out for... I use a rifle stock, so settled on a stock 5.2oz buffer and stock spring... still looking at a chamber ring system

Edited October 15, 2016 by Les Snyder

[Patrick Scott]

pfcchambers,

Is it possible with that side charger to run the bolt to the rear and use the bolt catch to lock it back all with one hand? If so how easy is it?  I think being able to do all that with one hand would make showing clear and flagging easier. 

[pfcchambers]

On 10/15/2016 at 1:48 PM, Patrick Scott said:

pfcchambers,

Is it possible with that side charger to run the bolt to the rear and use the bolt catch to lock it back all with one hand? If so how easy is it?  I think being able to do all that with one hand would make showing clear and flagging easier. 

With the Matrix arms, only side charger I have used, it an easy one handed motion. The more I use the side charger the more I am liking it. Just shot a 6 stage steel challenge match this weekend with the pcc. Gun ran great, all my show clears were performed in the above manner. It is easier than a traditional charging handle.

[Patrick Scott]

pfcchambers,

This may be a strange request, but maybe you can help me out. If you were to run a normal carbine buffer and buffer spring with no spacer in the buffer tube would the fake gas key contact the "trap door" in that matrix upper? I have heard some conflicting info on that. Thanks 

[pfcchambers]

23 hours ago, Patrick Scott said:

pfcchambers,

This may be a strange request, but maybe you can help me out. If you were to run a normal carbine buffer and buffer spring with no spacer in the buffer tube would the fake gas key contact the "trap door" in that matrix upper? I have heard some conflicting info on that. Thanks 

I have not run it with a standard carbine buffer, but I have ran it with the Kaw Valley pcc specific buffer and spring their solid 7.5 oz combo. It worked well and had no issues. The only differnce a standard buffer should have is being shorter and lighter. I don't see how that would come in contact with anything. 

[Bamboo]

Lots of good info and tips in this thread, Thanks.  Tagging for future reference.

[Malarkey]

So what is your final conclusion between the KVP and the JP? Since the reliability is the same, is it worth the extra $200 for a smoother action?

[1911luvr]

(If anyone has tried the POF flat trigger in an AR-9 and has had, good results let me know.)

I'm running the POF 3.5lb flat trigger in my NFA upper/lower LRBHO combo with JPSCS and Spinta BCG. It's been perfect so far.


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[pfcchambers]

Thanks for the info. 

[troupe]

Just read the write up.  Great job !

[Malarkey]

On 10/30/2016 at 5:38 PM, pfcchambers said:

I have not run it with a standard carbine buffer, but I have ran it with the Kaw Valley pcc specific buffer and spring their solid 7.5 oz combo. It worked well and had no issues. The only differnce a standard buffer should have is being shorter and lighter. I don't see how that would come in contact with anything. 

What is your preference now? The $385 JP BCG/Buffer set-up or the $179 KVP BCG/Buffer set up?

[pfcchambers]

The JP bolt is nice but I would save your money on a bolt and get either a KVP or even cheaper a Spinta blem. Having all 3, a JP, KVP and Spinta I can not tell much differnce. I do prefer the JP silent captured spring. It's just so much smoother, and once you get used to it, so hard to go back to the sprung sound. 

[1911luvr]

The JP bolt is nice but I would save your money on a bolt and get either a KVP or even cheaper a Spinta blem. Having all 3, a JP, KVP and Spinta I can not tell much differnce.

I will never go back to a standard bolt now that the 1-piece Faxon is out. After breaking the gas key and reading about so many others that have had the same issue, I'm selling mine and going this direction.


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[Warsaw214]

Excellent information, I just wish I looked here first before setting out to re-invent the wheel...

 

I originally intended to build a PSA AR9 prototype as a test build to customize, however, after delivery delays (30 days) I was forced to invest in an insurance policy due to shortened test window.  2nd investment build is has a PSA lower, Timney 3lb trigger, Blackhawk grip, heavy duty buffer tube, (trigger, buffer & spring combo TBD.... parts are due in later this week and planning on tuning for 130 PF).

 

Upper: Spinta BCG & billet upper, KAW Valley 16" barrel, Radian Raptor charging handle (replaces BCM), JP comp

 

 

 

[Warsaw214]

**Loads Developed with pictured above custom build (new frontier armory lower (PSA), with Spinta BCG & upper with KAW Valley precision 16" barrel) were with Xtreme 124g jacketed RN, 1.132 OAL,  CCI primer

 

Autocomp 4.0gn  PF=129

#2  3.4gn  PF=130

3N38 5,5gn  PF=137

WST 3.6gn  PF=132

WSF 3.8gn  PF=129

HP-38  3.4gn  PF=128

 

 

Edited March 7, 2017 by Warsaw214
Typo 5.3 should be 5.5gn

[IntenseImage]

**Loads Developed with pictured above custom build (new frontier armory lower (PSA), with Spinta BCG & upper with KAW Valley precision 16" barrel) were with Xtreme 124g jacketed RN, 1.132 OAL,  CCI primer
 
Autocomp 4.0gn  PF=129
#2  3.4gn  PF=130
3N38 5,3gn  PF=137
WST 3.6gn  PF=132
WSF 3.8gn  PF=129
HP-38  3.4gn  PF=128
 
 

Pretty close to what I found out. My normal load is 3.7 wsf under a 147 Xtreme. This was a little bouncy in the AR9 so I swapped the 147 out for a 124 and the gun flattened out