SVT - 40 - Problems

[Paulinski]

My boddy took his newly aquired SVT - 40 to the range this saturday. Beatifull example however it was esentially single shot gun. Firing two different kinds of ammo (Hungarian Ball and Czech silver tip) the gun was jamming on every mag.

Either stove piped or extracted the spent case about 5mm and locking up the action. You'd had to jerk the action to eject the round. Cases looked fine I didn't see any bulges or signs of headspace problems.

I read that there is a gas valve that can be adjusted. Any info is appreciated.

Thanks

Paul

 

[Stevo]

Not enough gas is getting to the system. The regulator is the 5 sided "nut" sticking out of the gas block at the end of the barrel. Either use the proper regulator wrench or remove the handguard and loosen the the piston guide off so you can turn it by hand.

 

[svt-40]

Before you crank up the gas regulator, give the chamber, specially the Revelli grooves, a good thorough cleaning with wire brush. The grooves have to be clearly visible and deep.

Generally, cranking up the gas regulator has to be the last resort when dealing with extraction/ejection problems of SVT, due to its receiver design. With gas regulator wide open, the bolt strikes the back of the receiver way too hard, eventually bending the receiver more and more. It makes the problems worse.

Cleaning the regulator is a good idea too. To turn the pentagon you need a wrench or just loosen the square nut of the gas piston, push the regulator in and re-insert in the right position. You can safely go from 1.1 to 1.3, but before you go to 1.5 you have to eliminate all other possibilities like rust or gunk in the chamber.

I read of someone fixing his ejection (not extraction!) problems by going down from 1.3 to 1.1