Pneumatic buffer vs spring
For many years I used a pneumatic unit instead of a spring behind the bolt of my HP AR15 I shot in competition. I also had a Tubbs weight in the back of the bolt. Both worked very smoothly. I quit shooting HP and LR about 6 years ago.
I went and fired at a range and had problems getting the bolt returning to battery. Checked the pneumatic buffer, and found it no longer had any pressure.
I am now shooting CQB in a AR15 with a A1 stock. I just finished a 2 day course where I ran through 1000 rounds. Boy did I find the squeak squeak squeak of that spring in the stock irritating.
I am shooting a LMT 14.5" upper with a SJC compensator, so it is pretty steady.
Do these units have a short life? (If so how long)
Is there any advantage to using one of these units vs the squeaky spring?
My old unit was adjustable, but there is no way I can see to recharge it.
Are there any a