SVT 40 troubleshooting

[BMWR12 35]

I took out my SVT 40 out today for th first time. It is a 1941 Tula non Russian Refurb, not import/non Finnish marked. I got the gas system set to the ammo I am using, brass cased surplus.

 

The gun seems to stove pipe and jam on occasion and also has a problem stripping the first round off the mags. I have 3 Mags for it, 2 SA marked and 1 Svt 38 mag. The mags seem to all be in good shape. It looks like the round is hitting where the mag lip meets the chamber feed ramp. Do these mags require fitting to the gun? Should I change the recoil springs and gas piston and cylinder? The original gas system looks brand new though. Any help would be appreciated.

[Maksim 1,504]

Wait for GlennP to respond, i know he has some experience with the SVT's... I am sure USNMars or Petros may be able to assist.

[Pew Pew Plates 358]

Yep,

 

Firstly, I'de reccomend the stainless gas cup and piston, they were floating around surplusrifleforums.com for awhile (a GREAT svt40 board there too)

what setting is your system at? If its at a reasonable (or below reasonable) setting, I'de kick it up a notch and see if the problems goes away. Although the feeding is unlikely to be solved by that, you may as well try. My SVT mags did show evidence of tinkering to get them to feed, but that rifle is a whole other story

[usnmars 136]

It sounds like it may be short stroking. Try adjusting the gas system maybe 1 notch higher. I think I run 1.6 or 1.7 with Russian light ball. I normally get it to cycle and go one settig higher, just for reliability. I have never had any mag issues so I can't help ya there.

[Pew Pew Plates 358]

It sounds like it may be short stroking. Try adjusting the gas system maybe 1 notch higher. I think I run 1.6 or 1.7 with Russian light ball. I normally get it to cycle and go one settig higher, just for reliability. I have never had any mag issues so I can't help ya there.

 

 

You need a new cup and piston dude, 1.7 is the top setting. I heard people cycle the russian LB with 1.2 or so with the new cup and piston. Finns have the 1.1 opened up to a full 2, BTW.

[usnmars 136]

Yeah it doesn't like the Russian at all. With Hungarian lb it will work on 1.2, polish lb and Bulgarian goes

like 1.3. It absolutely hates the Russian though. My gas piston is near perfect, just doesn't like Russian ammo--lol

[BMWR12 35]

The gun is an oddity,it is not import or Fin capture marked but has intials carved in the stock like some bring back K98s have.It looks like everything but the bolt/bolt carrier and trigger guard match and it came with a Svt38 mag. Im running it at 1.3 with brass cased russian surplus. Im am just trying to be careful because this gun reminds me too much of my K43 which nearly blew up in my face with blank ammo due to a improperly made repro gas cylinder that was in it before I got it.

[Radek 73]

Not to jack the thread ...

 

Dude, you got a BMW R12!? We got to meet up! I have a FJR1300 and a FZ1.

[BMWR12 35]

Yes 2 R12's not R1200

[Radek 73]

Absolutely gorgeous!

[junkmanted 54]

+1 on the new piston and cup, I first took mine out and it operated fine for the 1st 2 rounds after that I had a bolt action SVT 40 .

Also make sure your gas port isnt clogged from barrel to gas block .

[BMWR12 35]

Absolutely gorgeous!

 

Thanks!!! It is a never ending project to keep improving this bike. It is the earliest Military mass production(matched numbers) R12 known to exist.

[BMWR12 35]

I am still having problems with my SVT. The problem is that when it fires and ejects it will load the next round and the bolt will close all the way except for the last 1/8". It will also do this if you short cycle the bolt.It will do this with or with out a magazine installed. If you install just the bolt carrier it will slide freely then it needs a little effort to close up the last 1/8". Is this normal? Can someone with an SVT that works try this for me? Thanks

[Maksim 1,504]

Pic of the gun? Might it be an earlier version?

[usnmars 136]

it may be cruddy flutes in the chamber. Take the little trap door at the back of the receiver that is for the trigger guard latch and rotate it 90º. Put your cleaning rod through the hole and that gives you access to the chamber with a cleaning rod. Screw on a .45 brush onto the rod and go to town scrubbing back and forth not rotational. If the flutes in the chamber are cruddy this is the way to get em clean. it takes some time but that will get the chamber area perfect. If that doesn't work you could drive out the locking key and remove the muzzle brake. It is a pain in the arse to do but it gives you access to the gas port.

[junkmanted 54]

will the bolt close with no ammo ?

 

if no

take the gun apart and work the bolt and carrier by hand and you need to look and take your time and find what its hanging on .

 

maybe order new spring's

 

has it ever worked since you have owned it ?

 

did you change the cup and piston ?

 

Did you clean and oil ?

[BMWR12 35]

1.Yes,but only if the bolt is pulled all the way rearward.

2. Installed new springs and gun would not cycle at all.

3. It did work but not relabily

4.No because they look brand new.They are not stainless though.

5.Yes

 

As mentioned before If I remove the bolt from the bolt carrier and install just the bolt carrier in the receiver it will slide all the way freely. When it is 1/8" from being closed it needs some effort. Is this normal?

[junkmanted 54]

sorry i havent replied sooner I dont have internet since the storm !

 

You need to take your time and keep working it by hand and try and fine what its hanging on.

 

When things calm down I would like to look at it with you .

[BMWR12 35]

sorry i havent replied sooner I dont have internet since the storm !

 

You need to take your time and keep working it by hand and try and fine what its hanging on.

 

When things calm down I would like to look at it with you .

 

Got a spare bolt carrier today and it has the same issue so, I am guessing a the reciever is the issue.

[BMWR12 35]

So your original posts problem.is cleared up? And now has another.....??

 

The first seems.to be to be the actual magazine on reading.the thread ....seems the found is dipping on.strip if.I am reading it right...

 

The other problem of.the bolt not.closing .... is another matter .....dis you change all spring.on the rifle?

 

Have you completely checked the gas system to.ensure it.is.in spec? Etc...

 

The original problem is still there. I have changed the sprigs and all that stuff. The gas system is good. I think the cause of my problems is the bolt carrier hanging up on something. I think I am about ready to send it out to someone who works on them.

[junkmanted 54]

how far are you from livingston ? Do you want to swing by sunday around 4 ?

 

We can compare and swap parts from my gun to yours, and hopefully figure it out

[BMWR12 35]

I live probably 90mins away. I am in Jackson by CJRPC. I couldn't do tomorrow.