Filthy cases shooting suppressed (piston AR)

I've noticed that when I shoot suppressed I get quite alot of carbon blasting back into the action, enough so that the rounds in the magazine get cruddy too. If this is what a piston AR is like then I can't imagine what a DI gun is like? I have my gas regulator set to the lowest setting too but it doesn't make much difference.

Without having done any research into the issue, And this being my first AR... My only guess is I need a heavier buffer? Like an H3 or an H3 silent? I'm guessing the back pressure from the suppressor is causing the bolt to open slightly before the piston hits it And some of the gasses still burning escape around the shell?

The piston unlocks the bolt if the bolt opens too soon your gun would blowup, the back pressure from the suppressor blows the crap back into the action
because it can't get all get out through the front end of the can,

Macca

It's an AR thing I guess

The cases extracted from my AR and the first few rounds in the magazine are almost black after just one shot.

I've just accepted it and moved on.

Cheers
Pete

Have you tried reloading with smokless powder instead of 3f?

Mine is a DI and when firing off a string any remaining rounds in the mag start changing colour. Brass cases start going green within an hour. Life with a suppressed AR, get used to it ;)

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Originally Posted by Macca

I've noticed that when I shoot suppressed I get quite alot of carbon blasting back into the action, enough so that the rounds in the magazine get cruddy too. If this is what a piston AR is like then I can't imagine what a DI gun is like? I have my gas regulator set to the lowest setting too but it doesn't make much difference.

Without having done any research into the issue, And this being my first AR... My only guess is I need a heavier buffer? Like an H3 or an H3 silent? I'm guessing the back pressure from the suppressor is causing the bolt to open slightly before the piston hits it And some of the gasses still burning escape around the shell?

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DI is pretty much the same as piston, the blow-back from the gas tube is relatively minimal. In either system the majority of the blow-back is a result of the bolt unlocking while there is still residual pressure in the bore. A piston AR will unlock sooner than a DI so slightly more blow-back will escape from the chamber.

A heavier buffer will theoretically help decrease blow-back by delaying unlocking, but the difference will be barely noticeable. The A2 buffer is nearly the same weight as an H3, so if you've got an A2 tube on your gun already, an H3 isn't going to make any difference.

People get too caught up with DI guns claiming they are "dirtier" than piston guns especially in regards to shooting suppressed. How dirty they get isn't really much between the two systems and what is often missed is direct impingement AR's are slightly better in terms of accuracy.