Hi there!
I bought a nice A&K svd dragunov from another guy on ASC 3 weeks ago and after I adjusted the hop-up, it begins double-feeding.
So I tried MANY MANY things and I just invented a real way to make it stop double-feeding.
First: Make sure your hop-up screw didn't broke the little silicone tube under it. This white tube is really fragile and if you put to much stress on it, it will tear. If it's broken (like mine was) just take an old Wiimote silicone cover, cut a tube, insert it in the hole. Also, take another mini piece and place it right under the screw so the metal won't eat your brand new homemade silicone nub!
Second: Use a 6mm drill to increase the gap that is supposed to maintain the BB in the chamber before the nozzle comes back and pushes it in the bucking.
http://img641.imageshack.us/img641/3...ionnement2.jpg
Third: Insert a little bag wrap under your bucking just like in this picture so it will put a little more pressure on the front of the BB before it enters the bucking.
Fourth: Put some black tape over the wrap part that's coming out and also over the o-ring. It should increase your fps in the same way.
VOILA! From now your svd dragunov should be perfect! I tested it again and again and it never misfeeded. I must warn you that your bucking will probably have to be changed more frequently because of the nozzle pushing harder on it. If so, I suggest you choose a tougher one.
I hope it helped you and if it worked for you too, share with others!
Bozzy.tactiks