SVT-40 cycling issues? Or ammo issues?

Basically, look to make sure that the holes in the regulator aren't partially blocked by cosmoline or powder residue. If that's not the case, try increasing the gas regulator to 1.5.

Eventually, the SVT WILL work.
 
Don't worry about the discoloration - this is typical of SVTs and is a consequence of the fluted neck design. Gas leaks back into the chamber from the neck flutes. With wear, the gas erodes a channel in the neck and body area of the chamber. Your pictures show only moderate wear so this isn't the source of the ejection problem.

If it partially cycles on 1.3 then there is probably no problem at all - just turn up the gas. Some of mine will cycle on 1.2 and one will only cycle on 1.5 using the same ammunition under the same conditions. The gas regulator is designed to account for rifle-to-rifle variation in addition to ammunition, weather etc.
 
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So I cleaned everything again, I see the holes in the regulator and they are free of any cosmoline or dirt. I notice that when the regulator is set at 1.3 the hole is not lined up, when it is set between 1.2 and 1.3 the hole in the regulator is lined up with the hole on the regulator channel. In the attached pic I've slid a pin through the two holes.

C60F29AB-E236-4018-A834-907F75BAC30E.jpg

The above pic is when the regulator is part way between and the pic below is when it is set at the proper setting it seems the hole is not aligned.
620EB82A-9111-4505-8869-E08937B8880F.jpg

I was wondering if when set at 1.3 if I should see any holes aligned in the regulator. If not then I will crank it to 1.5 and try it again next week when I get out to the range. Again thanks for the input.
Regards,
Dave
 
Those two holes should NOT be lining up. You want the holes to be in line with the barrel and vent to the piston, not to the air as your pin is showing. Therefore the number should be FLAT and facing UP. The hole in the top is not for indexing, but rather to facilitate cleaning the passage to the barrel. Fits a pipe cleaner great!

See the pic in the first page that another member has posted. Set the gas to 1.7.

Also what is on the headstamp on the ammo you are using? I was using a particular factory of chinese stuff and it had the same issues with any gas setting on both my SVT rifles. Same symptoms as you have described. After switching to any other ammo, they were working great (privi, wolf, S+B, LVE, Russian surplus). If you have the same factory ammunition as I do it can be a potential culprit.
 
Mmk - looks like there's a bit of a misunderstanding on how the gas system works. The gas plug only works when properly indexed to the gas port in the barrel. Since there is an odd number of settings none of them will line up with any other when at the correct setting, which is a good thing or else the gas would vent out the top of the gas tower rather then back against the piston. When you poke a pin in through the top of the gas tower, you're following the path the gas would take if the plug were rotated 180* so that the opening faced the barrel. The hole in the tower you're poking the pin through is possibly just a remnant of when they drilled the port in the tower... long story short it isn't really useful to you.

In order to deep clean the gun you'll need to take the gas system apart rather than working at it from the outside.

Here's a vid of the complete takedown top to bottom. Very good quality and straightforward.

While you have the gun apart, clean the heck out of it with hot soapy water. The hotter the better. Most russian milsurps have so much grease and cosmolene hiding throughout them that they never quite work as well as they could. Hot water melts it out and soap cleans it... works better than any solvent.
 
I did take all the parts of the gas assembly apart and thoroughly washed with soaping warm water the dried then washed with solvent. Gun is now back together, lightly oiled and when next I'm at the range I will start at 1.3 setting then increase to 1.5 if it doesn't cycle properly. I also picked up 20 rnds of commercial ammo as well to try that at 1.3 and so on to see if ammo is the issue. I have not checked the head stamp of current surplus ammo but will post up when I do. I do know it was the cheapest I could find at $229 for 880 rnds.
 
Today was the day - set at 1.3 - cycled 1 round and stopped - reset it to 1.5 and it cycled with no further issues. Had a blast and a sore shoulder as well after about 30 rounds down range. But I'm smiling.
Thanks to all for the great advice it's working well.
Kind regards,
Dave
 
Sore shoulder????

WTF?????





hehehehehehehehehehehe

just kidding!!

Glad you had fun with your SVT!!
They sure are a great rifle to shoot, arent they?
 
BTW, original factory setting was 1.5, then after breaking in it should have been changed to smaller setting. 1.5 a little too much for a used rifle. Check all gas system parts for movement with no friction.
 
My Svt's function flawlessly on 1.5 also, so I keep 'em there. Happy shooting, and remember with that ammo to always take her apart and give her a good cleaning, especially the gas-system, and the regulator.
 
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