[Redstate]

The PSA should serve you just fine. The barrel is made by FN on the model you are looking at. I have the complete PSA Classic lower, and I have the Premium BCG, a charging handle and the PSA Freedom Upper (mid lenght)(melonite) in the UPS system right now.

 

[Redstate]

cfr, as stated in a previous post, I have one of the Freedom melonite uppers on the way with the premium BCG. I fully intend to run this one very hard to see how it holds up. However, that will take some time. As to PSA (not the Freedom line), you may want to check out this torture test performed by Palmetto State Armory on You tube:

 

[Redstate]

cfr, if you are saying you are lost concerning mid lenght gas system, the simple explanation is as follows. The 16" barrel can basically have a mid length or carbine lenght gas system. The difference is in the placement of the gas block (which in your case would be the front sight post) where the midlenght gas block is closer to the muzzle than with the carbine lenght gas system. The mid lenght system is said to result in less recoil, less wear (mainly as to the bolt) and a longer sight radius.