gas impingement to piston
I have an LMT CQB, thinking about converting from Gas Impingement to Piston by buying the upper receiver and monolithic rail system(piston conversion kit with piston bolt carrier group, H2 buffer). good idea or bad idea? would it be better to just buy an brand new complete LMT Carbine?
Had a piston MRP and sold it
Piling on, I know... Don't go with the piston. I had a piston MRP that I came by quite unexpectedly. Was stoked at first, until I ran a mid-length gas system with an H2 buffer. The piston is a very violent operating system, and will - in my experience - slow you down as your sights will move more than they will with a good gas-system. As was already stated, a piston is heavy, and the MRP piston especially so.
Bottomline: I do not think the piston will be worth the money you will spend. I also do not like the MRP in general, since I could (obviously) not swap rails out as I needed to.
I bought the hype to some degree. You should buy ammo and training time with people who will teach how to run your rifle as hard as you can.
zk