SVT-40 Feeding Problems...?

You need to investigate the exact ammo that was designed for use in the SVT-40, in case material and bullet shape and weight. Mid-20th century semi-auto rifles can be picky. Even the M1 Garand may have issues with ammo that is not M2 ball ammo.

Most surplus 7.62x54R ammo that you find these days is designed for eastern bloc machine guns. Commercial ammo is designed for modern commercial bolt action and the few modern semi-autos. (Mosin Nagants will pretty much eat anything.)

I also HIGHLY recommend that you do a headspace check.

I have to say that you might be in denial your purchase.

It's having a major malfunction from the moment you first started shooting it, after buying it for well under normal cost...and yet you (for some reason) INSIST that there's no way it can be something wrong with the gun. How the heck do you know that? The fact that it's got matching serials and good bore and you can't find problems with the springs does not mean it's not having mechanical issues that it shouldn't have. The science of well operating rifles is not as simple as whether or not things look shiny a new-ish. There could be thousands of things wrong that you'd never see by looking it over with your eye.

Am I saying that's what it is? No, I'm not. But it is possible, and you need to recognize that possibility.

The head space is really good on it, everything else seems to function flawlessly. I've heard that Bulgarian surplus works really well, but some people say just any brass case over steel works. I'll be testing both tomorrow.

(1) could be junk ammo (2) Not a junk gun; good bore, deep grooves, mostly matching serials, clean bolt, clean gas regulator, very good receiver and spring(s), the mag spring seems to be good also. (3) May consider if nothing simple works (4) Did that, taken it completely apart like 4 times just for fun (5) Well, it was $950 and the estimate I got on it after I bought it was $1380, soooo....

Either way, great collector piece regardless.

It may well have been cheap because of feeding issues. The first thing to check with any feeding issue is the magazine. Make sure it's a factory magazine with no obvious issues like bent feed lips or dings in the side. After that, you want to look at the feed ramp.

(1) junk ammo (2) junk gun (3) take it to a gunsmith because you don't know what to do about it (4) watch a YouTube video on how to clean it...properly. (5) How good a deal is it, now ?

Yeah, when I have a problem gun I also sell it off at a good price so it becomes someone elses problem.