Questions about mechanical problems with SVT40.

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VuDu666

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Hello gang!
Hopefully someone can point me in the right direction.
Subject: 1940 Izhevsk SVT40. One of Corwin imports with Russian made repro scope/scope mount (from what I was told). Original owner probably shot less than 20 rounds through it, I put maybe 100. Rifle was basically brand new when I got it. No gap between rear of receiver and dust cover from hot loads, I took out more bluing by mounting/taking off scope mount that previous owner did. Even gas piston was nice and shiny.
Ammo: Russian milsurp and some commercial heavier 182 grain non corrosive ammo in a blue box, might be PPU (didn't save the box but it was purchased from the range and they did not have any milsurp).
Gas setting: First time I shot it with milsurp gas was set at 1.5. It refused to cycle and kept failing to eject. I bumped it up to 1.7. Cycled fine without a scope mount.
Symptoms: After FTE problem was solved rifle was taken apart, cleaned thoroughly and taken back to range in about 3 months. Now, when scope is mounted, bolt keeps bringing dust cover forward with it. Not every shot, so it's not improper assembly, first time I fired last weekend, first round was fine, second shot caused above mentioned problem. Field stripped it, put it together, loaded the mag. Fired 3-4 shots, dust cover went forward again. Rifle doesn't seem to be doing in without scope mount present. Another thing. Rifle decided to chew up rear of recoil spring after 2-3 mags. I cut off 2 damaged loops, everything went back to normal and I shot about 20 rounds with iron sights without dust cover going forward but still. What could've cause this?

Thanks in advance!
 
The SVT recoil spring system is DIFFICULT! Sounds like you are not getting the spring to mount in the dust cover bracket properly.
Have several looks at svt1940's pictorials in the stickys up above^^ and you will get it sorted out.
 
I looked at pictures and watched videos. Figured if it cycles properly by hand 20 or more times than recoil spring/recoil rod should be seated properly. I can literally do dry cycles all night long and every time bolt returns to battery just fine but once I start shooting it all different story.
 
Hmm first thing that come to mind is a binding recoil spring guide. I know you said you assembled everything right but i suggest you check again. Make sure the spring guide hook perfectly in the rear cover. Read the SVT 40 sticky if not already done. I dont see why the scope mount would interfere in any ways. Keep us updated.
 
I have had a similar issue with my SVT. It was the springs, not so much how they were seated but how what order they were put in or arranged I guess. It was like if I put the springs back together in the wrong order or orientation it would jam up. Now that I have it working 100% I just make sure when I take it apart I keep the springs in the same order / orientation as they were. Not sure if it's the problem but might be worth a try. I think sometimes the spring would get too far on to the pin/plunger that hooks into the dusk cover.
 
I think i know what could be the issue. If the guide is not properly hooked in the cover, the hammer can interfere with the spring. If you cycle the action by hand with the hammer remaining in cocked position, the problem wont occur but im still thinking about spring/guide not assembled correctly.
 
I've gone through SVT stickies here (might've missed something, I'm only human), also spend some time on youtube, watching videos. I'm not the kind of person who just gives up and asks for help as soon as something goes wrong. This particular SVT is not the only firearm I own but is the only firearm I have problems with. I own something similar when it comes to recoil spring/spring guide setup - an SKS. Not a single problem, ever. I have half decent manual skills ( work as an electrician ) and have tools on hand. So far I failed to find a reason, that's why I made the post. I did have experience with AKs back in the old country. So, this is not something new to me. Figured someone else might've had the same problem. For some reason I think it has something to do with the mount unless SVT mechanism functions dry differently than when it's actually cycled by gas. That I have no idea about and have no way to check right away since I live in the city.
 
SVT's are fussy and need just the right handling of the parts in order for things to go smoothly, many have spent lots of hours puzzling over
this "Mystery wrapped in an Enigma tucked inside a Riddle" to quote Churchhill's comment on Russia.
 
Robert Nicholson, I knew that SVT's were finicky but had no idea it'll be like this :) 3 of my friends own one and no problems whatsoever.



Like I said before, it works fine without mount present. No problems with dust cover getting brought forward. Fine to the point, like 5 shots fine, another 3 and one FTF, than another 2-3 shots and than another FTF but I'm guessing it's gas setting issue since I used different kinds of ammo last time out (grabbed wrong ammo can in the morning so I took some milsurp from a friend and than bought some commercial).
 
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If three of your friends own them , maybe get one of them to take the gun apart and re assemble to see if you still have the problem. I sometimes have issues with my action jamming up. dis assembly and reassembly fixes it temporarily
 
welder01 said:
If three of your friends own them , maybe get one of them to take the gun apart and re assemble to see if you still have the problem. I sometimes have issues with my action jamming up. dis assembly and reassembly fixes it temporarily
Click to expand...

Two out of three were actually at the range with me. I ran into this problem 3 or 4 times so I asked one of two guys to give me a hand with closing the rifle. I fired a mag - no problem. Put scope back on - 2-3 shots - dust cover gets dragged forward by the bolt or recoil spring or whatever else. Took scope and dust cover off, put it back together myself, without a scope, fired another 2 mags - no problem. Scope also looks like it's mounted the way it supposed to, there is really no other way to mount it since mount has 2 rails and receiver has 2 groves on it...
 
It's weirdest thing ever. Worst case, like I said, I'll just wait for warmer weather and spend a day messing around with the thing on my friends property
where I can shoot it since I don't really want to fiddle with all the parts on a range bench in cold weather.
 
Sounds like the mount is squeezing the dust cover into the bolt carrier. Id hazard that you need to remove some metal from it to reduce tension. Either that or grease the piss out of the inside of the dust cover to keep it from grabbing the bolt carrier.
 
Robert Nicholson said:
The SVT recoil spring system is DIFFICULT! Sounds like you are not getting the spring to mount in the dust cover bracket properly.
Have several looks at svt1940's pictorials in the stickys up above^^ and you will get it sorted out.
Click to expand...

I strongly agree with this. when properly seated the spring pushes the bolt carrier and the dust cover in opposite directions. So if it's in there correct and for some reason the bolt catches on the dust cover it shouldn't move at all(definately not drag the dust cover forward). The only way I see this could happen is the spring is jumping out of or is not correctly seated in the dust cover and its cycling sks style with the dust cover just floating there. I think there must be some damage to the dust cover, or the spring guide. Perhaps pictures of the way you have it assembled and those two parts would help with the diagnostics.
 
I took pictures of bolt and dust cover. Pretty low res ones since I have a flip phone, no scratches on both parts, after 200 rounds and all those bad jams. I can really do pictures of assembly right now, being single now and having a flip phone....
I'm looking at the end of recoil rod, it's up all the way up, sitting in the dust cover and it's flush with dust cover. I'm sure it's gets to that little grove too when locking dust cover...
 
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Thanks for all the tips guys! I cleaned the hell out of chamber with a drill, put front recoil spring to the back and rear spring to the front. Set gas to 1.5. Rifle worked fine yesterday. Put about 150 rounds of Russian milsurp through it. Bolt didn't lock after last shot couple of times and rifle failed to load rounds out of magazine maybe 10 times but that's probably mag related problem. Otherwise everything worked really well. Now I can finally enjoy SVT shooting experience :)
 
I don't like these multi piece recoil springs setup, when taking off the dust cover I always get the feeling it's going to fly off and it's tricky to get the back of the recoil spring guide back into the notch on the dust cover on my svt. I assembled my Venezuela fn-49 wrong, the bolt kept on jamming, took it back apart and found the spring got kinked during assembly.
 
Great to hear that VuDu666 is getting fairly good results. That may be as much as you can hope for. I have never done more than 50 rounds
thru my SVT in a day without some problem. Some days it is only 2 rounds. It is part of the experience! For dependable, carefree fun, use an SKS.
 
Good to hear, I've been lucky with both mine. One or two hicups which were gas setting related, once it runs right it's a joy to shoot. I can see why the Germans liked it so much, it's my fav Milsurp to shoot.
 
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