My PSA PA10 adventure

[Robb in Austin]

Howdy all. Figure I might as well join in the fun and document my build.

Little background: I built 2 AR15 lowers about 2 years ago. Never built an upper. 

In the interim, decided I want to hunt at some point and decided .308 was the caliber of choice. Initially I was looking at a budget bolt action and probably will still get one but.... Sitting around a few weeks ago, texting a friend, and remembered the unused lower build kit I had sitting in the closet. Hit up PSA and see a stripped lower for $80. Boom, done. 

So; 

PSA Gen 2 stripped lower

PSA 18" stainless 1/10 Mlok assembled upper

PSA MOE lower build kit (slowly acquiring the necessary parts for PA10 lower)

CMC Trigger drop in

Armalite carbine length gas tube

Armalite buffer system(spring from Primary Arms, 6 position tube and buffer from DSG Arms)

 

I'll add pics as I can.

 

 

[Robb in Austin]

Got in my Armalite setup(AR-10® 6 POSITION RECEIVER EXTENSION KIT (NO STOCK) – AR10REKIT01).

The buffer tube (Part # 10207025, AR10 receiver extension tube to be specific.) is the exact size as the one that came in the PSA MOE lower build kit. Obviously the buffer and spring aren't.

But, given everything I've read, is this still going to be ok?

 

Went an hung out with my buddy last night; his Aero Precision pivot/takedown pins fit(although I just did a dry fit, no springs/detent). For the most part. They stuck out a little bit, which would make actuating them easier, and the pivot pin head is a little large for the cut out in the lower. It wouldn't seat all the way due to hitting the cut out.

His AP upper also mostly fit onto my lower. A comparison of the lowers revealed some interesting differences too. I'll post pics of them when we build them out.

[Robb in Austin]

The upper. PSA Gen2 PA10 18" Midlength .308 WIN 1:10 Stainless Steel 15" M-Lok Upper with BCG & CH - 516447164(for the detail obsessed)

 

The Armalite gas tube in comparison to the one that came with the upper. Armalite version on bottom. I was very surprised at how little actual length difference there is but as you can see, it sits much deeper in the upper.

 

Here it is installed.

[MSchwartz]

On 2/8/2019 at 7:53 AM, Robb in Austin said:

The upper. PSA Gen2 PA10 18" Midlength .308 WIN 1:10 Stainless Steel 15" M-Lok Upper with BCG & CH - 516447164(for the detail obsessed)

 

 

The Armalite gas tube in comparison to the one that came with the upper. Armalite version on bottom. I was very surprised at how little actual length difference there is but as you can see, it sits much deeper in the upper.

 

 

Is that a mid length, carbine length or rifle length gas tube?

[98Z5V]

^^^  What's more into it on there that most people never, ever pay attention to - is the bend in the gas tube,.  Every single time you use an AR15 gas tube on your .308AR, you bend that gas tube out of proportion, and you're inducing more contact between the end of the gas tube, and the carrier key on the BCG.  It's a height-over-bore thing, and most people never, ever understand it.

Those are "midlength" -ISH tubes.  PSA doesn't make an 18" rifle-length gas system, and the barrel info came from the poster. 

AR15 midlength gas tube (generic manufacturer) versus Armalite AR-10 Carbine Gas Tube (there's only one manufacturer, that get's it right every time). 

[Robb in Austin]

Thanks for answering for me 98. Been a little MIA on the forum obviously.

Finally got all the parts in, plus extras, from PSA. I commented on the PSA subforum on AR15.com auto the lack of availability in parts for these. A few weeks later and they are in stock enough to remain on the site into the afternoon.

I grabbed the classic lower build kit because it popped up first and then 24hrs later the PA10 upgrade kit, which includes the bolt catch, pivot, take down pins and the mag catch. May try to sell off some of the lower build kit stuff I don't want.

 

Planning on a build a rifle party next week with a friend.

 

[Robb in Austin]

Build party pics!

First: parts comparisons. The PSA parts came from their "PA10 Classic build kit".

Armalite official tube on left. PSA tube on right. Of note, the Armalite one is the same size as the one that comes in the PSA AR15 build kit.

Arrmalite buffer on left, PSA H buffer on right. By hand scale, they felt comparable in weight.

Armalite spring on left, PSA build kit spring on right.

Final assembled pic! Yay! I added a UTG Bug Buster scope but that pic turned out crappy.

 

Now for the issue.

 

Can't fully cycle the bolt. It will pull back about an inch and that's it. I'm assuming the spring is too long and bottoming out. 98; your thoughts?

[mrraley]

13 minutes ago, Robb in Austin said:

Now for the issue.

 

Can't fully cycle the bolt. It will pull back about an inch and that's it. I'm assuming the spring is too long and bottoming out. 98; your thoughts? 

Just at first glance, you received some wrong parts.

What are the measurements on the tube?

The buffer on the left if for a rifle not a carbine.

The springs... well what are their lengths?

[jtallen83]

That is a rifle buffer, it will never allow the rifle to cycle with a carbine tube. Are you sure the Armalite carbine buffer tube is on the left? If it is I have to wonder what length that PSA tube is??????

@98Z5V

[Robb in Austin]

Guess the ole hand scale was off. My buddies too.

PA10 build kit H buffer.

Armalite.

Spring length. Armalite on bottom.

Buffer tube length. PA10 build kit version.

Armalite version. Kind of hard to really tell but the end of it is at that last line by 7.

[DNP]

You mean...6-15/16"?  I've seen that number before. That's what it should be. 

 

The Armalite buffer you are showing is a rifle length buffer made for a rifle length tube. That is the wrong part for the 7" tube. 

[Robb in Austin]

11 minutes ago, DNP said:

You mean...6-15/16"?  I've seen that number before. That's what it should be. 

Yeah. Never been good with anything past 1/4" units.

[jtallen83]

Read this thread for a little clarity on the buffer tube/buffer issue. I think you have an Armalite AR-15 carbine tube. 

 

[mrraley]

We were just having this same conversation in another thread...

   Read here...

Edited March 8, 2019 by mrraley

[edgecrusher]

4 hours ago, Robb in Austin said:

 

Armalite official tube on left. PSA tube on right. Of note, the Armalite one is the same size as the one that comes in the PSA AR15 build kit.

 

 

 

Can't fully cycle the bolt. It will pull back about an inch and that's it. I'm assuming the spring is too long and bottoming out. 98; your thoughts?

As other have said: PSA tube is wrong in so many ways. Your Armalite buffer is a rifle buffer and incorrect for this application. Armalite spring and tube are GTG. You need a proper buffer now. Be it Armalite or an AR15 buffer is should weigh in at around 5 ounces or more. Both will work with the rest of the Armalite parts.

[edgecrusher]

[edgecrusher]

Reference for size and weights. I use his products and while pricier than others it’s a small American made product and Im good with that. You don’t have too but the measurements and weights are correct on his chart

[Robb in Austin]

Thanks y'all!

[98Z5V]

Rifle buffer, and what looks like the Armalite AR15 carbine receiver extension. 

If running the AR15 carbine receiver extension is the goal, then you'll need to select the parts carefully (wisely).

If just running a collapsible stock setup is the goal, then just buy the Armalite AR-10 Carbine Recoil System as a package, because it's alot cheaper that way.  The AR-10 Carbine Receiver Extension is 7 5/8" internal depth, uses Armalite's own EA1095 spring, and AR15 H3 buffers (That's the direct equivalent of the Armalite AR-10 Carbine Buffer, identically). 

^^^   If that was the original intent, then it looks like the incorrect Armalite receiver extension was ordered...

Edited March 9, 2019 by 98Z5V

[Robb in Austin]

If I'm understanding you correctly, I need a new buffer tube and buffer?

Can't use just a carbine length buffer?

[98Z5V]

What was the goal?  You can run the 7.000" extension, with a heavy 2.500" buffer (like the KAK Industries) and the Sprinco Orange spring - those parts work well together, and are consistently manufactured.

[Robb in Austin]

The goal is for a collapsible stock. And buying as few parts as needed to make it run right with what I currently have.

 

Thought I bought all the correct parts the first time. 

[Robb in Austin]

I bought an H3 buffer and all seems to be well.