It took many revisions to the Hk to make it reliable and it was in nothing but testing stages during this. G3Kurz or Pointblank on the HkPro forums can give all the info about the MR556 and 416. G3Kurz was/is employed by Hk(IIRC).
The truth is piston guns built from the ground up are not for most shooters. LWRC and Hk charge a premium for their rifles. They are dependable and accurate. I love my HK's and would never part with them, that being said I would advise you buying the Colt,LMT,LaRue,PSA.,etc. You most likely will never need the benefits of the piston gun. There are only three piston rifles I personally would own the Hk(of course , since I do) , LWRC, Sig's 516 (it is made very very similar to the Hk).
Buy the Colt and know you have a great tier AR15. The price is great on these now and the new M4 markings are a plus to me.
Ruger hit the same bumps and roadblocks that other piston rifles have gone through. It is my understanding that they have the kinks worked out. But while I despise Colts customer service(personal experience) it is still one of the best rifles sold everyday. If you were near me I would put you behind my Mr556, you will quickly realize it isn't a magical rifle that makes you top dog at the range. It is a heavy solid built rifle that is no more accurate than any other. I just personally have always been an Hk lover. That's why I tell honestly, buy a good DI rifle and enjoy it. The price difference, in a piston system,is only worth it if you shoot many various types of ammo and a lot of rounds suppressed. Yes they stay cleaner, but it isn't hard to clean an AR. Just my $.02 on the matter
