Adjusting the gas system on an SVT-40

[Eric308]

Hi guys, I recently bought an SVT-40 and was wondering how to properly adjust the gas system? Thanks

Information

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[fernleaf]

There is a 5 sided nut with graduation marks at the muzzle end of the gas cylinder. The issue combination tool has the appropriate size hole, but a pair of pliers - or maybe a socket - may be used, be careful not to scar the nut. There are numbers marked indicating larger holes to bypass more gas to provide more vigorous extraction. This was originally designed for variable power ammo and extremely cold temps. Open the gas adjustment up to larger numbers until the extraction is successful. Opening too much will cause excessive forces on the action, so don't go to far.

[Adolf Galland]

I would use non-corrosive ammo when testing the rifle,I own one and found out that it's not the easiest to take apart like the SKS rifle, at the range to wash out the corrosive ammo,but not impossible.

[1911crazy]

Make sure you line up the scribed lines perfectly on the gas port adjusting screw because the gas port holes are very small. I did find that both my svt-40's run great at the 1.3 gas setting seems to be the norm. If you open it too far open like the 1.7 setting the bolt carrier will slam into the rear of the receiver. I had one do that before i noticed it was too far open on firing one round. Bill