What to do with older PSA upper?

[awp_101]

I've got a 16" 5.56 upper and BCG that I picked up from PSA in the 2015-2016 time frame. It's supposed to have an FN barrel (I don't remember if I verified if it does or not or how to verify). All I've done is swap out the handguards and it's seen less than 500 rounds to be sure and really probably less than 300. It's essentially been function checked but not pressure tested. I'm debating upgrading it or replacing it with a better quality upper with an eye to keeping it around as a HD/training rifle. It's not going to be a patrol rifle and if I have to use it as a go to war rifle we're all in seriously deep kimchee. I just want to try and head off potential problems before they strike.

If I were to upgrade it, what parts should I be looking at replacing out of need (uncutting corners that may have been cut) instead of just personal preference (optics, furniture, etc)? If it's an FN barrel I don't see any reason to rebarrel. BCG? The actual upper receiver? A frame and gas block?

The other options are a BCM mid-length 16" upper or building one with the parts I have on hand (mostly Aero). I've got everything but a barrel and I'd look at something like an ARP 16" barrel with bolt. Triarc is an interesting option but the only feedback I've received about their barrels comes from someone I know that has a business relationship with them so it's not exactly an unbiased opinion.

If there's really nothing significant to be changed on the PSA I'll use the parts I already have to either build a dedicated .22 LR (all I need is the barrel) or maybe an 18" DRM-ish kind of thing. If there's nothing redeeming about the PSA then I'll rebarrel it as the dedicated .22LR.

Thanks!

[ranger]

I would just shoot it until it breaks then replace the broken parts as long as it runs reliably. (You stated not a duty weapon).

PS: I have multiple ARs built with ARP barrels with good results - specifically 6.8 and 6.5G. Bergara has smoking deals on AR barrels - I have two, both 20 inch, one "heavy" and one "light".

[ASH556]

Post a good closeup pic of the gas key on the BCG. That's probably the most concerning area. Beyond that I'm sure it'll run fine. Start with an H2 buffer if you don't already have one and I'll bet it'll run an H3 even better. I had one of their 14.7" SOCOM barrels that was supposed to be FN, double-thick chrome, hammer forged, etc. Still, PSA spec'd the barrels even if FN built them and mine came with a .07 gas port on a carbine gas length. That's over-sized. I suspect PSA did it for the same reason Bushmaster and others do it: so they don't get complaints from guys who try to run their guns dry with Wolf (and other crappy low-pressure ammo) and then complain that the gun won't run.

[awp_101]

Thanks ranger and ASH, I'll try and get a pic of the gas key tonight. I'll have to see how (or even if) the buffer is marked.

[Casual Friday]

Check the staking on the gas keys, verify the barrel nut is torqued to spec, then run it. The FN CHF barrels are well made, but like Ash said, they're overgassed. I have one with a springco blue and H3 buffer and it will still cycle wolf and tula ammo. It's my dedicated training gun/loan it to friends who don't have one and want to go to the range gun.

[Casual Friday]

Thanks ranger and ASH, I'll try and get a pic of the gas key tonight. I'll have to see how (or even if) the buffer is marked.

If it's the buffer that came from PSA, I'll bet you 5 PF wooden nickels that it's a standard carbine buffer.

[MistWolf]

I'll second the recommendation of a H2 buffer.

PSA extractor springs are marginal and not very durable. Replace it with either a Colt or Sprinco M4 spring. No O-ring.

[ASH556]

I'll second the recommendation of a H2 buffer.

PSA extractor springs are marginal and not very durable. Replace it with either a Colt or Sprinco M4 spring. No O-ring.

^^^Dig this!

Overgassing exacerbates extractor wear since everything is moving/unlocking faster. I know Crane specs the whole O-ring thing, but I've seen them cause problems and don't even run them on my suppressed 10.3.

[awp_101]

Thanks, I'll put some extractor parts in the Brownells cart. Like I needed an excuse to place an order...LOL!

The buffer probably came from an LBE buffer tube kit. The upper was a standalone PSA purchase and I assembled the lower from various parts kits during the same time frame.

[MistWolf]

Thanks, I'll put some extractor parts in the Brownells cart.

Let me stress there is a good reason I recommend Colt or Sprinco extractor springs. When you get the extractor springs from Brownell's, make sure they're Colt. The Colt spring was developed specifically to fix extraction problems that plagued the early M4s. Crane spec'd an O-ring as part of an extractor upgrade kit. The reason it was needed is because the military refused to approve the new spring because it would introduce a new part number into the system. Finally, Colt convinced the military to approve the new spring for use in the M4 and M16s and to stock only the new M4 spring.