Your Ruger has some good points. Like the rifle length gas system. don't quote me on the exact pressures, but let's say for example the carbine short tube experiences 30,000 psi. Mid length 20,000 psi and rifle is down to 12,500 psi. So you can use lighter buffer springs and weights to cycle correctly.
I have an AR 20 inch stainless match forged everything, squirrel gun that has in excess of 15,000 rounds through it. The only thing that I have replaced are the piston rings and bolt cam pins. I use a clear/amber Mil spec grease internally on the BCG and 3-IN-ONE-3-oz-Multi-Purpose-Oil-Long-Lasting-Lubricant everywhere else.
Before you fire the rifle take the piston out and thickly coat the bolt assembly, rings, and firing pin. The bolt cam pins really take a beating and need that grease cushion. I wore so many out in my different AR's that even the super stainless hardened that I found the roller bolt cam pins to be super durable. I have both of these roller designs.
The reason for coating the whole ring area of the bolt assembly is that they get hard carboned up on gas guns. When its really greased up with products like Grizzly Grease it makes cleaning in a solvent tank so much easier. Oh if you are a reloader CFE 223 AR Comp Power Pro 2000 MR Leverrevolution Ramshot big game are much cleaner burning. Stay away from h335
I built all my AR's and early on used the best nickel boron BCG's. Over time nickel boron discolors and I went to the best Chrome BCG's. Because I could buy the finest parts and barrels. My competition .223's are dime sized groups at 200 yards using max of 75 and down to 62 grain match bullets. Oh and I did convert a few of my best rifles to piston vs gas tube. Just a world of difference on cleaning and functionality. Just part of the learning curve.
The new Ruger AR-556® Multi-Purpose Rifle ("MPR").
This custom-built modern sporting rifle features an 18" nitrided alloy barrel with rifle-length gas system,