SVT40 failure to extract (like Mosin Sticky Bolt Syndrome?)

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Beadwindow

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Hi All!

I took my SVT40 that I got on sale from Epps a couple weeks ago out to the range this weekend with the hopes of sighting her in and having some fun. Beforehand, I read the instructions online to tear her down and insured that the working parts were clean (i.e. not loaded with cosmoline) and operational. The gun was a 1941 mixmaster, arsenal refurbished and I think it hasn't been fired since the refurb. The bore wasn't perfect, but had strong rifling like some other milsurps of mine that still shoot fine.

When I tried to fire her, the gun fired but failed to extract the casing. I had to hit the op rod handle against the bench to free the casing from the chamber and as soon as it was loose, it came out as it should. It needed quite a stiff whack (equivalent to a few sharp taps with a rubber mallet). The cases (laquered Czech ball) looked fine, so I'm not sure what's causing it. I've heard of Mosins having this problem though, especially with the laquered ammo, and thought that the SVT might be suffering from the same predicament.

I tried to clean out the chamber with a nylon chamber brush on a wire that let me rotate it thoroughly. I also used a good deal of windex and patches, but other than perhaps making it a bit easier to pop the casings lose, the gun jammed just as before. After several shots, I gave up and thought I'd post here to see if anyone has any advice or suggestions.

Cheers,

Frank

PS. The bore was also really sensitive to corrosion. I performed a couple pull thoughs with a bore snake and windex at the range Saturday evening, but found the whole bore quite a mess by Monday morning. It cleaned up with lots of boiling water, which I had intended to apply to it, but I'm still impressed with how quickly the corrosion formed in the bore.
 
Beadwindow said:
Hi All!

I took my SVT40 that I got on sale from Epps a couple weeks ago out to the range this weekend with the hopes of sighting her in and having some fun. Beforehand, I read the instructions online to tear her down and insured that the working parts were clean (i.e. not loaded with cosmoline) and operational. The gun was a 1941 mixmaster, arsenal refurbished and I think it hasn't been fired since the refurb. The bore wasn't perfect, but had strong rifling like some other milsurps of mine that still shoot fine.

When I tried to fire her, the gun fired but failed to extract the casing. I had to hit the op rod handle against the bench to free the casing from the chamber and as soon as it was loose, it came out as it should. It needed quite a stiff whack (equivalent to a few sharp taps with a rubber mallet). The cases (laquered Czech ball) looked fine, so I'm not sure what's causing it. I've heard of Mosins having this problem though, especially with the laquered ammo, and thought that the SVT might be suffering from the same predicament.

I tried to clean out the chamber with a nylon chamber brush on a wire that let me rotate it thoroughly. I also used a good deal of windex and patches, but other than perhaps making it a bit easier to pop the casings lose, the gun jammed just as before. After several shots, I gave up and thought I'd post here to see if anyone has any advice or suggestions.

Cheers,

Frank

PS. The bore was also really sensitive to corrosion. I performed a couple pull thoughs with a bore snake and windex at the range Saturday evening, but found the whole bore quite a mess by Monday morning. It cleaned up with lots of boiling water, which I had intended to apply to it, but I'm still impressed with how quickly the corrosion formed in the bore.
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Did you try adjusting the gas regulator? If I remember correctly it has 5 settings. Scrub the chamber real good. What did your empty casings look like? Were the flute lines on the neck very evident? If they are light its because of the mentioned laquer build up. Try it with some sellior and belliot soft points and see how it functions.
 
KyleSchenk said:
Did you try adjusting the gas regulator? If I remember correctly it has 5 settings. Scrub the chamber real good. What did your empty casings look like? Were the flute lines on the neck very evident? If they are light its because of the mentioned laquer build up. Try it with some sellior and belliot soft points and see how it functions.
Click to expand...

I was about to suggest that; if your regulator is set to 1.1 or 1.2 try 1.3 or 1.5. Lower is preferable, it won't beat up the rifle more than needed. Also make sure to align the notch of the selected regulator setting to the one on the muzzle extention otherwise the gas may not go through as it is supposed to.

I had two fail to extract like you, but with brass-cased cartridges. To clean my chamber I used a 30.06 bronze ratchet brush (the m1 garand type) and a lot of solvent. As KyleSchenk told, the flutes should be very apparent on the necks of your fired cases, these flutes help with the extration.

My particular rifle had a REALLY dirty bore. Like it has been shot extensively before being dipped in cosmoline, took ages to clean it properly. The same crap must be in the bore of your rifle.
 
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Thanks fellows!

After the first shot failed to extact I changed the gas selector to the 1.5 setting, but not surprisingly it wasn't enough to extract a case that needs a solid whack to extract.

I did not see any flute lines on the case head, and I wasn't sure if that was a sign of cosmoline build up or whether the flutes were a later modification of the original design. The advice here does seem to make sense. I have a Garand ratchet tool around somewhere and will definitely dig it up. In the meantime, I'll also work on the bore!

Regards,

Frank
 
Nah it wasn't an evolution, even the SVT-38 had these in the chamber. As you seen, the fired cases are hard to move in the chamber, I suppose that the way to bolt locks and unlocks (by tilting) it makes it hard to extract compared to a rotating bolt; thus the addition of flutes at the neck to help the extraction motion.

Try removing your bolt carrier and put light through the chamber you should see the flutes, they should be quite easy to see that way.
 
Thanks again for the advice!

I found my Garand tool in the butt of my M1 and gave the chamber a good cleaning.

I had also completely forgotten that once the bolt carrier is removed that there's a hole at the back of the reciever though which I could direct the cleaning rod. So I gave the bore a better cleaning with some JB Bore Paste to at least get it as clean as it's likely to get.

I also gave her one last cleaning of the bore with a pot of boiling water, and I'm pretty sure that she's good to go now. When I shine a light into the chamber, I can clearly see the flutes and it looks as though they're completely free of the cosmo.

I'll keep my fingers crossed until I get her to the range. In the meantime, thanks again for the help!

Frank
 
I found that on a few SVT40s I've come across, the gas setting needs to be at 1.7 in order to allow sufficient gas flow to push the gas piston back so a casing can eject. If you haven’t done so, I strongly recommend you do. Some people say that at 1.7, damage may be done with your rifle....that is complete BS. Sure some SVT40s may look rough and loose on the outside, but I’ve shot at least 2000 rounds out of my 1941 Tula and haven’t had any problem with gas setting at 1.7, even while quickly emptying a 10 round mag ;)

Don't only using boiling water, use soapy water to get everything clean, expecially if its been in storage for the last 50-70yrs. Use a few brushes, and scrub, scrub, scrub! Rinse after and reoil/lube and you're good to go!

Beadwindow said:
Thanks again for the advice!

I found my Garand tool in the butt of my M1 and gave the chamber a good cleaning.

I had also completely forgotten that once the bolt carrier is removed that there's a hole at the back of the reciever though which I could direct the cleaning rod. So I gave the bore a better cleaning with some JB Bore Paste to at least get it as clean as it's likely to get.

I also gave her one last cleaning of the bore with a pot of boiling water, and I'm pretty sure that she's good to go now. When I shine a light into the chamber, I can clearly see the flutes and it looks as though they're completely free of the cosmo.

I'll keep my fingers crossed until I get her to the range. In the meantime, thanks again for the help!

Frank
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Weren't lacquered cases designed to make feeding in semi-autos smoother? A bit ironic!

In the last months of World War II the Germans tried steel cases with lacquer. They jammed almost every time in bolt actions and made MG-42 barrels single use only (1 burst then it was done). At least we've come a little way since then.
 
ReZeNeR said:
I found that on a few SVT40s I've come across, the gas setting needs to be at 1.7 in order to allow sufficient gas flow to push the gas piston back so a casing can eject. If you haven’t done so, I strongly recommend you do. Some people say that at 1.7, damage may be done with your rifle....that is complete BS. Sure some SVT40s may look rough and loose on the outside, but I’ve shot at least 2000 rounds out of my 1941 Tula and haven’t had any problem with gas setting at 1.7, even while quickly emptying a 10 round mag ;)
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If the rifle needs to be set at 1.7 your piston must be trashed and I suppose makes no resistance in the cylinder, not very good. Normally it shouldn't damage the rifle, but sometimes...something breaks... Thanks to the handguard I still have my thumb... :eek:
 
I had the same issues with my SVT 40, among other things, there was cosmoline jamming the gas regulator, I missed it during cleaning, but after about 5 shots it melted nicely and I set the regulator to 1.5, it seems to work well for this Czech military crud out right now (silver tip, laquered case, 1980's or 60's)
Peace,
A
 
toya said:
If the rifle needs to be set at 1.7 your piston must be trashed and I suppose makes no resistance in the cylinder, not very good. Normally it shouldn't damage the rifle, but sometimes...something breaks... Thanks to the handguard I still have my thumb... :eek:
Click to expand...

The rifle was designed to go to 1.7 with no threat to the thumbs of the operator. Set the gas regulator to whatever works.

The two primary causes of FTE in these old rifles:
- Lack of proper cleaning
- Lack of proper lubrication

Look there before moving further.
 
These rifle have a fluted chamber, They need to be cleaned (the chamber). I agree with "greendoh"

The two primary causes of FTE in these old rifles:
- Lack of proper cleaning
- Lack of proper lubrication
 
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