Fired them all yesterday (Sunday). Just trying to do the recommended barrel break-in. Clean after every shot for first 10 shots. Had them all shooting bullseyes withing first five shots. I will include my target for the last 5 shots. we were only shooting from 50yards, as that is what we can at my dads range. My target shows what appears to be one hole to the left, but is actually two shots, then I adjusted the scope and fired three more (still cleaning between each shot). Accuracy in my opinion was VERY GOOD for brand new barrels, and being cleaned between every shot!
My load was 37.0 gn of Lil Gun, 250gn Hornady FTX, length is 2.260" Chambering and extraction was flawless. Velocity through my chrony measured 2314fps. My cousins load was with H110 (hornady's max listed on their load data...not sure what charge that is) His velocity was 2279fps. His accuracy was also very good. It does appear the 24" barrels are adding a noticable velocity difference compared to the listed data for a 16" barrel.
To Answer Pitted Bore....I do not own an AR 450B, so I cannot compare recoil. I do know that fully scoped my rifle weighs in at 9.8lbs. Recoil from my sand bags was noticable, but NOT uncomfortable. More than my Muzzleloader, but less than my 30-06.
My picture of my target is added. And I only have one more thing to say....When is Hunting season???? hahaha
It's not the size of the Dog in the Fight that matters....It's the amount of Fight in the Dog!