PSA is a budget brand that is great for general use, but there are lots of things you could do to improve accuracy. Before I can recommend anything I would need to see your groups to be able to see whats happening. There are general things you can do in order to improve accuracy but really need to see you shooting at a target prone supported, paper, 25 yards. Just be advised with a thinner barrel than normal, you are not going to be able to shoot fast and maintain your grouping due to barrel heat. Even free floated barrels will move once heated from too many shots.

MattLA is correct, PSA is a budget brand, but they will do more than 99.9% of the people who use an AR will ever ask it to do. He is also right in that since your skill level is unknown to any of us it may not be the rifle. What others have also said is correct in that a bad trigger will turn a 1" rifle a 1.5" or 2" rifle very quickly. There are a ton of variables involved which are hard to diagnosis over the internet really all people can do is answer your specific question and there has been a lot of good advice given thus far.

https://www.larue.com/products/larue-tactical-mbt-2s-trigger/

$89. MACHINED FROM TOOL STEELS. hugest quality and best prices drop in I have found

Before i would do anything, especially if I was new to ARs (i don't know if you are new to them or not), I would shoot one of my buddy's ARs that is a proven nail driver to rule out that the problem is my gun or just me being unfamiliar with ARs. It took me a while to get used to shooting one. Something about the recoil spring ringing in my ear bothered me to the point of losing my concentration.
I have overcome that since then and now all of my ARs miraculously have become much more accurate.

you using a solid rest?

I'm not a sharp shooter by some of you guys standards but I've got bolt rifles me and boys can constantly shoot sub Moa with and we all can shot our 270 right at Moa at 400 yds using our setup. Maybe an AR shoots different, this one is the only one we've shot. I put it together as a gun just incase the wheels fall of and I need it to keep me and family safe. Wasn't needing a tack driver and can live live with it for that. I'll drop another trigger in it and see what it does. I got a couple other lowers I bought just because I could and thought it a good idea to have them while I could get them. Was think about putting together another that shot a bit better or at least 1 1/2 moa to shot coyotes out to 250 with and was wanting information on to how go about that. Thanks for all the input guys. Really appreciate it.

Do have a rem 788 with factory trigger that is terrible that I've shot for 30 years and I can shot sub moa at 100 yds all day long.

Shooting vise on front and sand bags on back

Gun appears to have a free floated hand guard

bag , bipod , rest?
rear bag
are you getting off that rather large gas block when you rest the gun to shoot your goups?


slim profile may ring it heat more more 1.5moa isn't all that bad that is all the better a lot of ammo will even do

1.5moa is 6 inches at 400 yards

that gun is sett up to be a light weight carbine , it is running a carbine length gas system , that upsets the rifle more and sooner than a mid length or rifle length
is it a round group?

for the role that gun is set up to serve 1.5moa is really not bad

what does the group look like at 200 yards?

what is your role for the gun , to be a light weight gun that is easy to carry and shoot or are you wanting a bench rest shooter