Short(er) FAL reloading question

[Mumbles]

I have a FAL with a 16" barrel. It didn't start out that way, it was shortened, so it seems to be a little undergassed. Works reliably on the max-gas setting, but less so on other settings, whereas when it had a longer barrel, it ran fine with the gas regulator on roughly the middle setting. I'm not looking to make any physical changes to the barrel/gas/etc. That's not what this thread is about, I'm just giving you the background information so that the rest of the thread makes sense.

Given that the gun seems to be undergassed, and that using a slower burning powder in a semi-auto results in higher pressures at the gas-port, would it be a good idea to try working up a handload that uses a slower-than-recommended powder for 7.62 NATO? Nothing drastic, obviously, but maybe the RL17 or H414 I discussed using with .308 in some threads from earlier in the year when it was near impossible to find IMR4895/Varget/RE15?

Is my line of reasoning sound, or am I completely missing some important detail?

 

[leadbullet]

when shortening an FAl barrel, the gas port need to be opened up a bit or the system will be under gassed. check that out first before getting a headache and having ammo specific to that very fine weapon.

 

[427Cobra]

Yep the gas port needs to be opened up, go over to The FAL Files - Powered by vBulletin when I built my STG myself I shortened the barrel and opened up the port, that was 15 years ago and I can't remember what drill bit I used, but with a little searching you'll have your answer and exactly how to DIY.