FN FAL Gas Regulator setting with different brands of ammunition

[paulnb]

I was adjusting the gas regulator on the new to me FN FAL based on the advice given on this forum and the Falfiles, to ensure the Bolt Hold Open device (BHO) stays open on an empty magazine. Below are the gas regulator settings that give reliable extraction, ejection, and BHO staying open on an empty magazine. Note that I was not checking accuracy of the various brands.

PMP 7.62x51 milsurp Ball 147gr (1984 batch) – regulator on 4.5
PMP .308W SP 150gr (new) – regulator on 3
S&B .308W FMJ 147gr (new) – regulator on 4
Norinco 7.62x51 milsurp Ball 147gr (1992 manufacture I think) – regulator on 3

Are these settings fairly consistent with other FALs? I read that barrel length can also influence the gas setting - my rifle has an 18” barrel. From reading the forums, I got the impression that .308 Winchester is loaded to a higher pressure than 7.62x51, but it seems not.

Given its 1984 vintage, the PMP milsurp performed really well and consistently compared to the Norinco which still had a couple of FTE.

[FNBROWNING]

Possibly a notch or two more open than I run mine but in the ballpark. Would be interesting to know a bit more about the rifle.

[A-R]

The reason why a FAL is adjustable is simply because they all have different setting for optimal functioning with different ammo and conditions. So set it where it cycles and activates the bolt stop on an empty mag, then close it 1 more click. If the action gets slowed down due to dirt or cold weather, close another click.