SVT 40 accurizing?

CANTOM:

Nice to see you are branching out into other rimmed cartridge rifles!

I get indifferent accuracy from my Ukranian and Finnish capture rifles. The first thing I noticed is amount of loose and rattling parts on the front end. The only thing I've found to do is tighten up the contact surfaces so the bands don't slide or turn.

Yeah, this old dog has learned some new tricks...;):rolleyes:

Plus which Mosins and SVT 40's have more ammo available than I can find in .303...:(

BTW, are you talking about SVT 40's with the loose parts thing?
 
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I doubt that there are a lot of people reloading for this but I will be putting together some reduced velocity handloads with cast bullets in the near future.

Are cast bullets a problem with a gas operated rifle, as in shaving lead at the gas port? And, reduced velocity with a notoriously finicky gas operated action? Also, the fluted chamber tends to make reloading a bit frustrating I've read.

I read one site where it was recommended to turn the gas regulator to an intermediate position to shut it right off, and operate it as a single shot, thus making cleaning of that gas piston arrangement a less necessary evil, particularly with corrosive ammo.
 
I have yet to disassemble an SVT 40 but hope to have a chance to do so soon. Obviously most feel that changing anything on a milsurp is sacrilege and will destroy it's value. Since I'm not going there, I had a thought.

The AccuWedge is an item inserted between an AR15 upper and lower to tighten the fit up. If the action on an SVT 40 actually moves in the wood, I wonder if an enterprising type could make up a hard rubber(or wood) wedge to temporarily put in the stock behind the action such that any ability to slop or move backwards is eliminated, but no permanent change to the rifle takes place at all?
 
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Yeah, this old dog has learned some new tricks...;):rolleyes:

Plus which Mosins and SVT 40's have more ammo available than I can find in .303...:(

BTW, are you talking about SVT 40's with the loose parts thing?

Yes.

AIR, the front band isn't a pinch style, so the parts fly in formation with a springy finger providing all the tension. And not much of it either. Pack the contact surfaces with paper and then give the rifle a heckuva good shake. No noise is the objective. If you've made the leap of permanent modifications, try some birch-wood coloured Bisonite or other bedding compound. Or, change the shape of a No.4 Lee Enfield front band, for example, and see if that changes anything.
 
Are cast bullets a problem with a gas operated rifle, as in shaving lead at the gas port? And, reduced velocity with a notoriously finicky gas operated action? Also, the fluted chamber tends to make reloading a bit frustrating I've read.

I read one site where it was recommended to turn the gas regulator to an intermediate position to shut it right off, and operate it as a single shot, thus making cleaning of that gas piston arrangement a less necessary evil, particularly with corrosive ammo.


I'll let you know how it goes :D

I was thinking of a heavy gas checked bullet, if it works well I'll work up a hunting load maybe. Yeah I know, fluted chamber, hard on brass, finicky gas system..But I just have to give it a try LOL:dancingbanana:.
I can't imagine that the gas hole would getting plugged too quickly. One way to find out.
Also I have not fired corrosive ammo in it, and I don't intend to.
 
yeah, I know, but I wouldn't want to bed it in place permanently either.

Truthfully, I can't think of a way to bed a factory SVT stock that would have any benefit. Like you say, a replacement stock would be the way to go if you really wanted to, but $$$ will be mucho.

Yes, looks like replacement stock is the best choice, i saw one custom in other forum, but no commercial so far.
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So most of the suggestions are that the inherent inaccuracies come from the wood stock and lack of proper tight fit to the gun, rather than the bolt, barrel, or sights being inadequate.

So theoretically, the gun itself is good; IE if one were to somehow grasp and fire the gun securely without its stock, it should perform better than with its stock on... Am I reading this right?
 
So most of the suggestions are that the inherent inaccuracies come from the wood stock and lack of proper tight fit to the gun, rather than the bolt, barrel, or sights being inadequate.

So theoretically, the gun itself is good; IE if one were to somehow grasp and fire the gun securely without its stock, it should perform better than with its stock on... Am I reading this right?

The sniper scope also tends to move on the rails, so you have the action moving in the stock, and the scope mount moving on the action...sounds like quite the setup...:rolleyes:

And yet, with good ammo, people say they're quite accurate.

One of those aftermarket stocks might make a big difference if they paid a lot of attention to bedding the action.
 
i am shooting my 40 yesterday and it was grouping 5-7 inch at 100 meter with Czech silvertip. I then pulled out a box of S&B RN and it went down to 3 inch. This was with all original and opens sights. it was a windy rainy day. Not the best conditions for accuracy, so i think they can do better. So yes they are fairly accurate for a gun produced in 1942.
I cant say this enough, these guns are just a joy to shoot.
One thing to watch out for. I was getting some extraction problems after about 100 rounds and i thought that it was the chamber getting dirty. But it was the gas port, it was loose and the gas adjusting pin had mored halfway between 1.5 and 1.3. So the holes weren't lined up thus a loss of ejection pressure. Just something to look out for.
 
I had the problem you described twice, the piston seems to like to unscrew itself, I'll try to secure it with teflon tape next time.


So theoretically, the gun itself is good; IE if one were to somehow grasp and fire the gun securely without its stock, it should perform better than with its stock on... Am I reading this right?

What do you mean ?
 
The sniper scope also tends to move on the rails, so you have the action moving in the stock, and the scope mount moving on the action...sounds like quite the setup...:rolleyes:

And yet, with good ammo, people say they're quite accurate.

One of those aftermarket stocks might make a big difference if they paid a lot of attention to bedding the action.

What do you mean ?

Cantom got me - What I was meaning was, "where is the problem in the design." From reading other posts it seems that people are saying the play in the stock means that the actual gun (reciever, gas system, barrel etc) are all moving around during each shot. If that is the main/only problem, then the solution would be to bed or build a proper stock for it.

If the problem were lets say, wobbly or poor sights, a gas system that wrenched the gun around, poor workmanship and tolerances, then it would be a completely different story.

Basically I'm starting on a project to turn my SVT 40 into an SVD clone - hopefully it will look as good as BBQ_Woa's one does. Since the project doesn't permanently alter any part of the gun, I get a chance to see where the faults are in the gun by shooting it in original full wood configuration and then shooting it basically bare (IE: with only a little handguard on the barrel, a tightly mounted lower reciever, and that's it.) Right now I'm trying to identify and solve the problems with the original design, so I can address them in the new project.
 
Cantom got me - What I was meaning was, "where is the problem in the design." From reading other posts it seems that people are saying the play in the stock means that the actual gun (reciever, gas system, barrel etc) are all moving around during each shot. If that is the main/only problem, then the solution would be to bed or build a proper stock for it.

If the problem were lets say, wobbly or poor sights, a gas system that wrenched the gun around, poor workmanship and tolerances, then it would be a completely different story.

Basically I'm starting on a project to turn my SVT 40 into an SVD clone - hopefully it will look as good as BBQ_Woa's one does. Since the project doesn't permanently alter any part of the gun, I get a chance to see where the faults are in the gun by shooting it in original full wood configuration and then shooting it basically bare (IE: with only a little handguard on the barrel, a tightly mounted lower reciever, and that's it.) Right now I'm trying to identify and solve the problems with the original design, so I can address them in the new project.


Very interesting project...gonna start a thread on it??:D
 
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I am 100% with you, no permanent stuff on this historic piece !

I have read somewhere about the finn evaluations of the SVT-38 and proposed ameliorations. They even made an improved rifle based on their observations. There were a few things that they didn't like:

-The receiver is too light: The locking shoulder is far from the chamber, with its light construction it is prone to bending when firing, gives the vertical stringing known from the SVT series. They advised using a much heavier stock and reinforcing the receiver, the latter was forgotten (cost factor) in the upgraded rifle but the new stock reduced the stringing problem drasticaly.

-Barrel is too thin: Prone to overheating and bending, we all heard this one especialy with the AVT-40's. But as with all rifles it is a very important aspect. Nobody makes SVT barrels, so it would be a custom setup that would still need the rear sight base and it can't be too fat for that and to leave enough space to the piston rod to travel... Unless you have a wasted shot out original barrel and a real ton of cash, forget about putting a kreiger on this gun... The finns did put a heavier one though.

-Muzzle extension, too complicated easy to see, the finns put on a simplier unit. I wouldn't touch this except maybe to add a stainless gas piston that some guy makes in the US and a tighter fitting piston rod.

-Rear sight, this one is a personnal preference. I'd prefer a scope to shoot at 1500m... And I personally like apertures a little more than tangent sights. I'm working something out with Mojo Sights on this one...

-Sling, with the ordinary stock it is bad, the finns got it right... I guess that with the navy stock it is better but it not a so much important factor for us here.

Anything that would hold the receiver thightly to eliminate the bending question should solve a lot of accuracy problems. Having some inside pictures of the different M14 EBR chassis might give you some ideas.
 
Very interesting project...gonna start a thread on it??:D

Lol - you know what? I might. It's Kasat's idea though, and I admit, a lot of my plans come from looking at pictures of his gun.

I'm thinking of two simultaneous build threads on cgn - one for the SKS/FAL and one for the SVT/SVD... this all provided that I still have 4 months to do the work in a properly equipted shop next summer.


I am 100% with you, no permanent stuff on this historic piece !

I have read somewhere about the finn evaluations of the SVT-38 and proposed ameliorations. They even made an improved rifle based on their observations. There were a few things that they didn't like:

-The receiver is too light: The locking shoulder is far from the chamber, with its light construction it is prone to bending when firing, gives the vertical stringing known from the SVT series. They advised using a much heavier stock and reinforcing the receiver, the latter was forgotten (cost factor) in the upgraded rifle but the new stock reduced the stringing problem drasticaly.

-Barrel is too thin: Prone to overheating and bending, we all heard this one especialy with the AVT-40's. But as with all rifles it is a very important aspect. Nobody makes SVT barrels, so it would be a custom setup that would still need the rear sight base and it can't be too fat for that and to leave enough space to the piston rod to travel... Unless you have a wasted shot out original barrel and a real ton of cash, forget about putting a kreiger on this gun... The finns did put a heavier one though.

-Muzzle extension, too complicated easy to see, the finns put on a simplier unit. I wouldn't touch this except maybe to add a stainless gas piston that some guy makes in the US and a tighter fitting piston rod.

-Rear sight, this one is a personnal preference. I'd prefer a scope to shoot at 1500m... And I personally like apertures a little more than tangent sights. I'm working something out with Mojo Sights on this one...

-Sling, with the ordinary stock it is bad, the finns got it right... I guess that with the navy stock it is better but it not a so much important factor for us here.

Anything that would hold the receiver thightly to eliminate the bending question should solve a lot of accuracy problems. Having some inside pictures of the different M14 EBR chassis might give you some ideas.

Good info - sounds like the only stuff that can really be dealt with without permanently changing it is the stock.

On that note - you mentioned the finns did something with heavier barrels, stocks and muzzle brakes? Were those only in the trial versions, or did they make it to production as well? It would probably be a very expensive rifle, but an interesting one to see pics of, or even own:).
 
As far as I know no rifles that were into development in finland were produced, there were a few designs, I think all stayed in the prototype stage, this includes the upgraded tokarev and any offspring. Seems Finland didn't have the structure to produce anything to replace the mosin-nagants in sufficient numbers at an adequate price per unit, so does the upgrading that we discussed earlier. Did they officialy used any self-loading rifle before the RK-62 got in production ?
 
I can add a bit to this now as I finally got my rifle and did a full disassembly, cleaning and reassembly.

With the crossbolt tightened up, the action does indeed move fore and aft a bit, felt like a sixteenth of an inch or so. I didn't check but assume that with the trigger assembly snapped into place it tightens the fit up, it's quite a tight fit to close that up.

BTW, I had trouble getting the trigger group back in. I got some advice and was trying to squeeze it closed but no go. Found a site on the net that advice a smart rap on the guard...worked like a champ.
 
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