which is the better operating system for the ar gas or pistion?

Do a search man.  There are bountiful topics on this.

Edit:  Not trying to be a jerk, but this topic always starts a fight.  Neither is better.  They are just different.

Both are "gas" by the way, the difference is where the "piston" and chamber are for the gas to do work.

Agree that this is (intentionally or not) a troll post.

Here's some detailed information on the subject.  click here

welcome ..just some friendly advice. Take some time to read and research all the posts on these forums and it may help you get a better understanding to the questions you have. Before I even signed up for a membership, I spent close to a year READING a ton of posts that interested me. It may serve you well to do the same...

True, notice my low post count? It's because nearly everything has already been answered. Look around, read and reread.

You can read around or take my advice from reading around.

If you want something that can shoot coming out of the water or shoot with a silencer 100% of the time at best performance then get a piston.  If you want tried and true, easy to find parts for and easy to use then grab a gas system.  I just got my first AR, and I went with a gas system.  I wanted the best and I felt the Noveske gas uppers delivered that.  If I were to build a silenced SBR that ran a suppressor 100% it would be LWRC.