gas system

I recently purchased my first M1A and I have been swapping out the parts I can with USGI. I recently came across a marked HRA gas system and was wondering if it's any good or if I should avoid HRA as I have heard mixed messages on them

I don't know that I really need to say more. I'm on the look-out for a Sadlak polished gas piston. It seems that every online dealer is "Out of Stock". If someone has one sitting on a bench somewhere...I'd love to put it to good use! Thanks! -Rodney USN5 ROWTB #6 When listing a Want To...