In case anyone is looking for SVT 40 scope and Mount set we have them for $298 link is below
http://https://www.corwin-arms.com/product/sniper-scope-and-mount-svt-40-rifle-0
For anyone looking to make sniper notch on your SVT 40 you can either make it tightly fit the mount or you can follow the picture below showing original factory specifications to make a sniper notch.
First before you start please check the rear of your SVT 40 receiver if it does not slop down too much if it does mount locking bar will not engage. Not every SVT 40 that has groves can be made into a sniper. On some of them rear portion of the receiver slops too much down. However if rear of your reciver is more or less straight which is almost 90% of the rifles with scope groves the Sniper Mount will install properly.
Making sniper notch is easier then it really looks, rear of the SVT 40 receiver is quite soft so there is no need for any machines hand tools will do.
You will need few items to make it
1. Callipers to measure the distances
2. Metal marker to mark the lines of maximum extent of the notch
3. Round Chain saw file best use 4mm is best for the job
4. Flat file with a narrow part of not more then 4mm
5. Some 200grid sand paper to make it smooth and round of the edges
6. Cold blue jelly type works best
7. Small brush to apply cold blue
8. gun oil for putting small coat on cold blued part
To start making a notch
1. Secure the rifle in a viese best by putting some cloth on the trigger guard so rifle is not scratched then securing tightly the rifle by the trigger guard
2. For proper notch measure the distances for the notch and mark them (if you want just the notch to secure the mount but do not care for proper look. just get the position after installing the mount on the rifle and marking place for the notch through lock pin hole. remember to remove spring plunger from the mount for proper fit)
3. Start filing the notch with the chainsaw file starting from edges make holes the proper depth as the diagram. Chainsaw file will allow you to make edges of the notch round giving it the proper look
4. Once 2 groves are made to proper depth with chainsaw file remove the remaining middle section of metal with the narrow face of flat file
5. Smooth the edges of the notch with 200grid sand paper, after smoothing the edges sniper notch will look proper
6. For anyone that has experience with case hardening you can case harden the notch to avoid any scratching or damage from the mount moving (SVT 40 mount will move back and forth on the groves it was designed that way) If you do not know how to case harden properly just leave it as is, to prevent scratching the notch by the mount just use small flat piece of brass from the case or from sink tubing
7. Clean the notch then warm it up a bit with a heat gun so bluing is better
8. Apply bluing to the area at least 4 times then after the last time put some gun oil on the bluing and let it set for few hours
Hope it helps
I took a Hand picked SVT from P&S Militaria but that's just me 
