Troubleshooting SVT40 Extraction/Ejection Issues

[Beadwindow]

Greetings everyone and happy Easter!

I just thought I'd write to see if people here could help me troubleshoot towards finding the precise cause and cure of extraction/ejection issues with my 1941 Tula SVT40 refurb.

I took the rifle out once about a year ago and had no luck getting it to extract without a mallet. At the time I discovered that my initial cleaning of the rifle still needed to get at the cosmoline in the chamber flutes, so I did a much more thorough cleaning and put her away. I should note that cleaning her out really chewed up the wires at the end of my Garand combo tool, so do keep that in mind if you clean the chamber with a brush!

I took the rifle out again two weekends ago and had some progress. We figured that the rifle would partially extract and then slam the fired case back into the chamber, which then needed to be tapped out. After a while, we found that the rifle would extract to the point where the front of the case would catch against the edge of the chamber and hold the action open (kind of like a stovepipe except that the case was facing down the length of the receiver). The progress went so far as two or three proper extractions, but that was out of maybe 40-50 rounds fired.

The ammunition used was laquered Czech silvertip, five rounds of some copper-washed surplus ball that a friend was shooting, and two rounds of Sellier and Bellot 180gr SP, the latter two types fired to see if they'd make any difference. There was no noticable difference between the results with brass or laquered cases and no sign of burrs in the chamber. The springs operating the bolt and gas system weren't stiff, and the gas settings used were 1.5 (initially) and 1.7 (the latter giving the 2-3 positive extractions). In the process of shooting, I did learn of the importance of tightly locking the gas system in place and properly aligning the gas ajustment setting, so those issues could be eliminated as the reason for my problems.

So what gives? Clean chamber, different ammos, properly tightened gas system at higher settings and yet I still couldn't get consistent extraction, turning it inot a slow single shot with a mallet or wood to open the action. At least the gun showed some suprprising accuracy despite the having to bring out the mallet between shots, and notwithstanding a dark bore with strong rifling.

I should add that I was at the range with a friend who regularly rebuilds numerous Chinese M14s, ARs and other rifles, who though not an expert on Soviet firearms he was able to walk me through much troubleshooting and observation of what the rifle was doing. All he could see as a cure would be to open up the highest gas setting, though imagining the scacity of that part, and wanting to get the rifle working at its regular gas setting I am at a loss as to what to do. Can anyone here advise?

The rifle seemed like a great buy (about $300 out the door at Epps) and it looks like it will be accurate enough (at least 2-3 MOA with suprlus ammo) once I get get her shooting normally. It feels pretty good in the hand and might become my favourite shooter once the bugs are worked out.

Please help....I'd greatly appreciate it!

Thanks,

Frank

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[jmoore]

notwithstanding a dark bore with strong rifling

Dark bore suggests corrosion which likely is in the chamber as well. If your brass looks "frosty" or rough textured after firing, there's your problem. About the only two ways to correct the problem are barrel replacement or chamber polishing. The downside to polishing the chamber is that the chamber will be enlarged- only slightly if done properly- and can easily be over done. Since the chamber is fluted it is already hard on brass, so if you don't reload, a careful polish may be your best bet.

Rebarreling? That's a toughie! No pre-made spares of which I'm aware. So that's gonna be expensive.

[Beadwindow]

The brass didn't show any signs of "frosting" or rough texture, and if there's any corrosion in the chamber it isn't readily apparent with a visual inspection using an LED Maglite. Incidentally, the darkness in the bore doesn't seem to be having a noticably bad effect on accuracy, since even with my having to reposition myself after each shot, the rifle was grouping nicely enough. Once it's working fine I think I'll very happy with its accuracy, which is all the more reason to get her extracting.

I think I'll get some lacquer thinner and maybe do a minor polish job on the chamber before doing anything more extreme. There could be old cosmoline remaining within the chamber along the lines of what causes mosin "sticky bolt" though it's been cleaned enough not to be visually apparent anymore. Also, on another board someone who had trouble cycling lacquered Czech ammo had no problems with copper washed Russian Ball, which I've since acquired.

Thanks for your suggestion. I've gotten some good tips from CGN as well, and between it all should have enough things to work on: trying different ammo, using lacquer thinner in the chamber, lightly polishing the chamber, keeping the gas system tight, trying both 1.5 and 1.7 settings (and maybe going down to 1.3 if everything works as it should).

Regards,

Frank

[jmoore]

Good deal if there's no brass damage!

How about your gas spigot and/or cup? Corrosion there might lead to excessive gas leakage, but crusty chambers are by far and away the most common drama.

There is visible sign of the flutes in the chamber doing their job, yes?

[Beadwindow]

The flutes were cleaned out well and leaving their distinctive marks on the fired cases.

I'll tale a look at the gas system again. There might have been some evidence of corrossion before the parts were refurbed with the rifle, but from what I can recall, everything looked fine.

Another thing I should point out that wasn't mentioned earlier is that the action was properly lubricated, and the gas system was dry. So I don't think that that was a source of any problems.

Thanks for the tips!

Frank

[1911crazy]

Disassemble the gas system and clean the little holes in the gas adjustment screw. The scribed lines on the gas adjustment screw need to be lined up perfectly or the small holes in the gas ports won't flow enough gas. The SVT-40 should operate with the 1.3 gas setting. Both of my svt-40's operated perfectly on the 1.3 gas setting. On the 1.7 setting the bolt carrier would slam the rear of the receiver like getting hit with a baseball bat in the shoulder. When you said yours is on the 1.7 setting something is wrong with your gas flow. Bill

BTW; My refurb svt-40 has all new parts in the gas system. I figure that most of them do if there cleaned properly. My refurb was still unshot do to the scribed lines on the gas valve not lined up exactly. It didn't cycle. There is no wear on the bolt face from the bullet cases(brass) so it was never operated in semi auto. I got a brand new unfired refurb.

I use moly in all my guns as a lube. Most of the semi auto's require a gun grease anyway.

[kar98k]

The SVT-40 should operate with the 1.3 gas setting. Both of my svt-40's operated perfectly on the 1.3 gas setting. On the 1.7 setting the bolt carrier would slam the rear of the receiver like getting hit with a baseball bat in the shoulder. When you said yours is on the 1.7 setting something is wrong with your gas flow. Bill

generally it's a case by case situation. many SVTs operate better on 1.7 even when perfectly clean. and 1.5 was the mid range, standard setting for it.

[RMXC51]

I've got 3 of them. Two work fine at a setting of 1.3, but the third, a 1941 Tula, runs best at 1.5, all using Russian surplus from around 1975. It does show evidence of minor previous corrosion in the gas system, where the other 2 (Izzies) do not. I would definitely check out the gas system as well as the chamber.