Your looking for a virgin in a whore house my friend. There haven't been any significant amounts of surplus long blanks around since the early 90s. They all got eaten up. I believe I have some left, they are film industry blanks. Very hot (big flash) and expensive $1.50ea. I have some left because I got them for my belt fed VZ-59s but the cases were to soft and would deform upon feeding, very violent feeding system. (sorry I digress). They will work fine in an SVT. I guess it's a case of how bad do you want them and if you know how to avoid blowing yourself up when it comes to blanks and non matching BFAs.