I don’t have enough money to buy a BCM 18” but I could possibly save up for an 18” BCM upper to swap out the upper of my Ruger 556 MPR 18”. I heard that the most important parts of an ar-15 are the uppers, BCG, barrel, etc. My MPR already has a custom trigger that came stock on the rifle. I saw a YouTube clip of a gunsmith that specializes in AR’s comparing a BCG of a PSA $400 vs Knights armament $4,000. He said because the machining and geometry of the Knights armament is more precise and the BCG is better quality the wear on it is much less vs the PSA BCG, and I’m assuming the barrel is obviously better on the latter too. If I replace my upper with say, a BCM upper, will that make the rifle more reliable, longer lifespan? Any advice if you don’t have the money for a mid tier AR but can afford swapping parts? Is it worth it?

The Ruger isn’t unreliable other than one time I took it to the range after only 150-200 rounds and the BCG froze due to carbon build up. I hear that the barrels and BCG of budget rifles have far less durability or life span

Your Ruger that you have now is a well built gun, using quality parts, and a hammer forged barrel.  I would say that you are in good shape as it is, no need to get the Gucci upper.  Just wanting to get another upper is one thing, needing one is another, and you dont need one.

If you do want another, go with the 20'', or 14.7

for all intents and purposes, PSA would be just fine.

Another vote for spending on ammo instead of an upper.  You can always purchase a 2nd BCG as a backup

Great, thanks for the advice, I haven’t heard too much about Ruger other than the few comments I’ve seen people saying they’re happy with it and that even though it’s budget priced it’s quality is better than budget. It’s an extremely comfortable, soft shooting rifle, I love shooting it and other than that BCG malfunction I  haven’t had any other, it seems everything else gets a lot of reviews except Ruger MPR. I’ve seen some YouTubers like Lukas from t-Rex arms talk about how budget rifles are good for practice but not for the test of time and that you might as well buy a mid tier rifle instead of upgrading parts which I felt kind of iffy about that. Why spend a lot of money for a whole new rifle when you can upgrade the areas that would make the rifle as good as a mid priced one? Anyways your advice is sound to me, thanks again

Dude, Ruger makes high quality guns. They’re not the “cool” brand, but they know what they’re doing. I’d be happy to have that rifle and I have a couple of pretty Gucci parts builds (solgw/bcm/larue).

Dude, Ruger makes high quality guns. They’re not the “cool” brand, but they know what they’re doing. I’d be happy to have that rifle and I have a couple of pretty Gucci parts builds (solgw/bcm/larue).

Absolutely nothing wrong with that upper, but it's not going to do anything measurably better for you. For the price of it, you can buy a case of ammo and an aimpoint pro and still have money left to take the ol' lady to dinner and grab a case of beer. That's the route I'd go.

This ^^^

Don't over-pay for a fancy roll-mark.

This. Ruger was making guns before the founders of BCM were even born. Hell, Bill Ruger could have met Eugene Stoner back in the day. A Ruger firearm has not always been highly refined but they're definitely reliable and a quality weapon.