Picked up a PSL-54c

[highpower3006]

A PSL54c isn't going to be a tack driver. That being said, there are a few things that you can do to improve how they shoot. I reduced the gas port size to .063" to reduce the recoil and battering on the rear trunnion. I also handload and I have been able to get it down to 1-1 1/2" five shot groups. They seem to like heavier bullets, but the large gas port beats up the rifle with them.

[WarPig1976]

I reduced the gas port size to .063"

Drilling and tapping for a plug with a smaller hole? That's how the suppressed guns have to run too.
If I go heavier I'd throw a $10 buffer in because then your beholden to those plugs if you drill it. I'll stay in the 150g range anyway, not worried about squeezing every ounce of accuracy out of this one. I have others for that.

[jjjxlr8]

I think buffers do more harm than good. They reduce the amount of travel and with the same spring you are increasing the opportunity for the carrier to make contact with the rear trunion, through the buffer.

I've had very good accuracy results with Czech light ball ammo in one of my PSL54C rifles.

[WarPig1976]

You may be right. I do know there are guns out there with buffers as OEM, The Winchester 1907 has a leather buffer.
Honestly I don't think it's a good idea either way to use the heavies. I'm sure I'll get satisfactory results with handloads compared to spam can stuff.

[cipherk98]

Tough thing with hand loads will be fixing the brass. Mine tends to dent up the case neck pretty bad, though I've heard some tape on the receiver cover where it ejects can help but I need to replace the gas tube lock first (was broken when I got it). We'll see I guess, I've been happy with the 1.5 MOA groups I'm pulling out of it with good commercial steel ammo but can probably improve on that with hand loads and a better trigger (probably an ALG AKT). Notably when I had mine apart it looks like someone had already fixed the hold open at least once. Mine has a neutered bayonet lug up front which I guess is better than not having it all, but I don't see myself fixing it as cost to get one (probably $60-75), have it installed, and then deal with 922r and replacing parts for that is more trouble than it's worth. Would rather spend the money on a red dot or 8x42.

Also, the other fix for shooting heavier bullets I read up on is to install a screw in the gas block as a regulator. Don't see myself doing it though, though I've had a hard time finding .311" bullets in a 150gr FMJ BT.

[highpower3006]

The port mod is very simple and took me all of about 30 minutes. The stock gas port can be accessed right through the gas block. It is exactly the right size to tap with a 8-32 tap. I bought a new three flute tap (stronger than a two flute) and using tapping fluid, it went as easy as can be. I bought several 3/8"x8-32 set screws and heated them red hot and let them cool slowly to take the temper out. I drilled one at .060, another at .063, and the last one at .070. I tried the middle one first and it ejects the brass into a pile about five feet to the right at three o'clock which is perfect. This is with 174gr Wolf. Before the mod, it would violently eject them 10-15 feet to the right at about two o'clock.

It takes just a couple of minutes to change out the screw if you want to increase or decrease the port size. I stick to heavier bullets as I like the way it shoots with them. I refuse to shoot the surplus light ball as I dislike cleaning corrosive residue out of a gas operated rifle.

The entire rifle feels better as the carrier isn't slamming the trunnion so hard. I have heard that after a while they will knock the rear trunnion rivets loose without the gas port reduction. It is highly recommended that you stay away from the recoil buffers as the carrier is still beating up the rear trunnion.

[Kalione]

That's some good tips there Highpower, it's been a good long while since I took mine out, I remember the kick, but I can't remember where the brass ended up. This thread is making me itch to take it out though, I've been meaning to spend a little time and fine tune that thing.

Make sure I'm understanding this correctly, your tapping the port in the gasblock itself, so if you decide you don't like the port mod plugs (for lack of a better term) and take them out, your just left with a threaded port, right? Doesn't seem like it would be that big of a deal, or cause any lasting damage. I guess worst a case scenario would be breaking the tap off during the mod, if you weren't being careful, something I've been known to do

[highpower3006]

Make sure I'm understanding this correctly, your tapping the port in the gasblock itself, so if you decide you don't like the port mod plugs (for lack of a better term) and take them out, your just left with a threaded port, right?

Correct.

I was a bit nervous when I first went to tap my gas block. The trick is to buy a new American made tap that has at least three (four is better) flutes. Use real tapping fluid and go slowly. Mine went very easy and I had no trouble at all tapping the hole to the proper depth. If you use a new (sharp) quality tap and a small tap handle and back off the tap every half turn or so, you should have no problems at all. Most of the taps that I have seen break, failed because the person doing it was using too big a tap handle to drive the tap and twisting too hard.

I think that once you tap the hole, it would be even more oversize than it already is, so I would say the best thing is once you find the size of port the rifle likes, and .060-.065 seems to be the optimum size, just resist the urge to tinker further and leave it alone.

I would stay away from using inferior taps and avoid anything made in China. I bought two taps, a can of tapping fluid and a box of set screws for around $35 shipped from MSC. I now have three lifetimes worth of screws, but they are small and don't take up much room. The up side is that I have found other uses for a few so I was glad I bought extras.