I need to compare some of my own rifles now. I got lucky and actually found some nice ones.
SVT40 Sniper Tula 1942 (Naval AVT stock, but converted into a standard stock)
SVT40 Tula 1941 (Naval AVT stock, without side rails - not typcial on an early rifle)
SVT40 Tula 1943 (Standard stock, without side rails)
SVT40 Ishevesk 1940 (Standard stock, Silver bolt, SVT38 Mag and four port muzzle break)
SVT40 Kovrov 1941 (Standard stock) - On hold
I found out that most of the rifles our there now have the Ukraniane "UN export marks", so I thought I would stock up while most of these rifle are $300-400 a piece.
I also was lucky and found two sets of original tools (wrench and stock take down tool). I also got two variations of the tools, which was lucky.
These web sites are a great reference:
http://mosinnagant.net/ussr/SVTsection.asp
http://www.jaegerplatoon.net/RIFLES4.htm
My big question is as follows. Are the four ported muzzle breaks late war? Or AVT specific? I have read both. If they are AVT specific that would make sense as surplus muzzle breaks, just like surplus AVT stocks would have ended up on standard late war SVT's and due to this fact, maybe they are mistaken as late war?
The problem is having originals to compare to. Almost all of our SVT's are aresenal refurb (mix matched parts), so no confirmation there. The other SVT's are Finn captures, less than 15,000 were captured and even less were exported, so again a lack evidence.
I have seen pictures of AVT's with the four port muzzle break, but this is not a definative study as I have seen maybe 3-4 examples.
Is there a great book on these rifles? Maybe I should write one?
These rifles are mentioned in many other books, "The German Sniper", "Hitlers Garands" and "The German Assault Rifle".