SVT-40 gas system issue

GunsNotPuns

GunsNotPuns

CGN frequent flyer
Rating - 100%
4   0   0
Location
People's Soviet Socialist Republic of Canada
This problem has been plaguing me for years and I figured I'd finally get around to fixing it. I'm not sure what the part is called, but the cross member below the gas port setting moves to the left (when staring down the rifle from the butt) during firing, leading to the SVT-40 failing to cycle and forcing me to mortar the bolt handle to eject the case.

It's not loose but generally within a few rounds of firing I'll have to mortar the rifle and then using a plastic hammer tap the cross member back into place to keep firing. Has anyone else faced this issue and remedied it?

I'd get into the gas port setting knob that inevitably becomes loose after a bit of firing but one problem at a time.
 
It is called a "Muzzle Extension Key" per Numrich's schematic. The key has a cut in the middle on both sides. I think if you remove it and then carefully use a fine cold chisel tap the cut to expand on the right side to prevent it from moving to the left. Never done it, but its worth a try.

The key has a hole which allows the gas to escape to the "gas regulator" with settings of 1.1 ~ 1.7. This is why the rifle is not cycling.

Maybe the gas cylinder is not tight enough against gas regulator. Loosen the gas cylinder to change the setting then tighten the gas cylinder again.
 
Last edited:
Slide the gas "member" key out. get a good hammer. Put gas key flat on hard metal surface and flare it a bit by striking on it so the key will increase in width. don't overdoit. slide it back in and tap in place. Repeat until its fairly snug. to align it ,there is a vertical hole that goes through the gas port housing and key all the way to the barrel. as long as you can see the rifling, then key is properly aligned
 
You must log in or register to reply here.
Back
Top Bottom