Sig556 Gas Valves

[Bret]

I ran a test today to compare the factory gas valve from my 556 Classic SBR to the Pierce Precision Engineering gas valve. Ammunition used was IMI M193 55gr FMJ.

I started out with the factory gas valve on the standard setting. The hole measures 0.047" (1.19mm). The five spent cases ejected an average of 31'.

I then installed the PPE gas valve and set it to port 5 which is the second from the smallest. The hole measures 0.039" (0.99mm). The five spend cases ejected an average of 16'

I then rotated the PPE gas valve to port 6 which is the smallest. The hole measures 0.034" (0.86mm). The five spent cases ejected an average of 6', but none of the next cartridges fed.

I then rotated the PPE gas valve back to port 5 and fired five more cartridges to verify reliability. Function was 100%.

The spent cases from cartridges fired using the factory gas valve have significant dents in their sides and some of the case mouths. Those from when the PPE gas valve was used look nearly perfect. I couldn't be happier with the PPE gas valve. If Sig had made a gas valve with the same setting, I think it would have had a significant impact on the rifle's reputation.

[SteyrAUG]

I ran a test today to compare the factory gas valve from my 556 Classic SBR to the Pierce Precision Engineering gas valve. Ammunition used was IMI M193 55gr FMJ.

I started out with the factory gas valve on the standard setting. The hole measures 0.047" (1.19mm). The five spent cases ejected an average of 31'.

I then installed the PPE gas valve and set it to port 5 which is the second from the smallest. The hole measures 0.039" (0.99mm). The five spend cases ejected an average of 16'

I then rotated the PPE gas valve to port 6 which is the smallest. The hole measures 0.034" (0.86mm). The five spent cases ejected an average of 6', but none of the next cartridges fed.

I then rotated the PPE gas valve back to port 5 and fired five more cartridges to verify reliability. Function was 100%.

The spent cases from cartridges fired using the factory gas valve have significant dents in their sides and some of the case mouths. Those from when the PPE gas valve was used look nearly perfect. I couldn't be happier with the PPE gas valve. If Sig had made a gas valve with the same setting, I think it would have had a significant impact on the rifle's reputation.

So you turned your SIG into a FAL? Seriously sounds like you got the fine tune rifle you were looking for.

[Bret]

So you turned your SIG into a FAL?

Basically, but the gas valve is easier to adjust and it doesn't weigh as much.