PSA Sabre 416 @ Home…A Journey…

[PFunk]

So, a month or so ago, a couple of guys named @GuitarGuy and @GamecockOperator advised me not to destroy a perfectly good Sabre upper in the pursuit of devising a short-stroke gas-piston version of the Sabre AR.

“Get an inexpensive Freedom upper,” they said. “It’ll be fun,” they said.

What they really said was, “what an idiot”.

Today, my Freedom upper arrived and I immediately began my quest by ripping it apart.

So, let me explain. Why do I have such a thing for gas piston rifles? Why can’t I live with DI operating systems? Let me answer your question with a question. Have you ever shot an AR left handed? Do you enjoy getting spit in the face by unburned powder and brass shavings?

I am solidly left-handed and left eye dominant. Actually, my left eye is the only one that works. So, for all those who suggest “just learn to shoot right handed”…

No.

In the world of gas piston ARs, you have very few choices. The best ones are prohibitively expensive. I wanted to see if I could convert a base model PSA upper to gas piston as cheaply as possible. To do that, you have two choices: Adams Arms or Superlative Arms.

I have an Adams Arms P1 upper now. I installed a Midwest Industries rail handguard on it, and for whatever reason, the best accuracy I can get out of it (with a 16-inch Faxon barrel) is 4MOA. Barely rack-grade accuracy. My Aero M4E1 with a Superlative Arms piston (and a 14.5 inch barrel) averages 2MOA with range practice M193 ammo. I wanted better.

I had a Sabre lower that I kitted out with decent components and I considered getting a Sabre upper until the guys here told me that was stupid.

So, here we go, gents…

[Jammo]

Sounds like a fun project to tackle. Good luck @PFunk

[GuitarGuy]

Sigh, I’m getting too old to remember. But good luck!

[savagemic]

I have multiple piston AR’s and I have not noticed them to be any more or less gassy than their DI counterparts. But I’ll never tell someone not to build another AR.

[1911]

I shoot left handed all of the time. I shoot all of my AR and AK and I also shoot them suppressed. I don’t notice getting a bunch of blowback in my face at all. I shot thousands of rounds through my M16 in the military and it never bothered me.

[MichaelAnthony]

i wear glasses every time i shoot because im afraid im going to be getting some blowback more than the casings but also for the casings and to see..

[PFunk]

Project Update:

So, here is the old upper (foreground) and the new one with the gas piston kit (background)

As I said before there aren’t many choices when it comes to converting a DI AR to gas piston. You have really just two, Adams Arms or Superlative Arms.

I’ll describe how each works:

Superlative Arms - there is but one type of gas block, and narrow is the gate the hand guards must pass through should they want to join in holy union with it and the upper receiver. Prithee, take this comically long Allen key and precisely turn yon bleed off valve exactly 28 clicks thusly in the same fashion as the clock to tune thy rifle in such a manner that thy suppressor doth not melt.

Adams Arms Micro Block - slap this there gas block on and wedge the op rod right there. To adjust, here’s a flat-tip screwdriver. There’s five settings. Go nuts.

Adams Arms Standard Gas Block - three settings: suppressed, unsuppressed, and disassembled for maintenance. Use your fingers. Wait for it to cool before you do.

The one in the foreground is an Adams Arms P1 with the standard picatinny block, which I think is what’s affecting my accuracy. The gas block is smacking my handguard every shot and I think that may be what’s throwing my shots off. It’s supposed to be free-floating, but I don’t think it’s working in practice.

I will miss this handguard because it’s nice, so it may eventually find itself in another build. I’m not throwing it away. The HexRail handguard from PSA doesn’t fit. The Superlative Arms gas block is just too big, so I ordered a Sabre handguard in the hope that it will fit.

If not, I have three options:

1.) Find another handguard that fits the PSA barrel nut.

2.) Hitch the handle of a wrench to my truck and try to remove the PSA barrel nut and use someone else’s with a matching handguard.

3.) Trade it in for a Mini 14.

[PFunk]

So, a month later, I have totally busted my budget. I had a lot of FTFs at the range and I feel like it’s the buffer; it’s too heavy. The bushing fell out and got jammed up in the action, marred up the inside of the upper receiver. It’s probably fine, I’ve seen much worse be functional.

So, I have to decide if I want to just start all over again. The PSA Freedom upper hasn’t thus far lent itself well to conversion to gas piston.

I’m going to use Loctite retaining compound to get the bushing to stay and go with a lighter buffer next range trip. If that doesn’t help, I’m pretty much throwing in the towel and going back to my Adams Arms P1 upper.

[GuitarGuy]

I’m glad you didnt mess up your Sabre upper….

[PFunk]

What a difference changing the buffer makes. After putting some Loctite retaining compound on the bushing where the piston enters the upper receiver and changing out the H3 buffer for an H2, the rifle ran like a sewing machine today.