[Steve40th]

SIg 516 uses H2 buffer, as far as I know. I dont think the gas settings will need a change, due to the wire being same, except flat and made of a material that lasts longer.

 

[Steve40th]

I just want to get rid of the "twang" and smooth out my cycling in my 516 without having to do anything additional other than put the flat wire buffer in. If I have to change the buffer and adjust the gas settings to shoot 55 or 62 grain ammo unsurpressed, I will not go with the flat wire spring and return it to my LGS.

Change the wire, that is all you need to do.
Some also put a little grease on spring. YMMV

 

[Steve40th]

Could just by an MCX, then you wont have the sproung noise, ever...

 

[Steve40th]

I have thought about the MCX, but I am not sold on that rifle at all! Way too many cycling and malfunction issues with the MCX for my liking.

I am so much more of a 516 fan and will just deal with the "sproing" since I am a weekend shooter and not in a Combat zone all day. I'll live with the "sproing" sound! More importantly, I am hoping the cycling will be smoother! Unfortunately, It'll be about a month or more for me to be able to shoot my 516 to give a report on cycling!!!

Ammo plays a big part in cycling too. I use 62 gr ammo, same manufacturer every time. This makes me consistent, as well as making rifle have no abrupt changes.. Try a low grade bullet and a high quality round, and see the difference in cycling.