Where to buy BDM Magazines

I just picked up a Savage 12 VLP BDM in .223 Remington and I have not had any luck in located spare magazines for it. Does anyone know who has these in stock?

Also, I purchased a "Fred Sled" from Sharp Shooters Supply and found that it only works with the first shot. After that the next rounds end up jamming up against the breech unless I push the magazine up back into place. It seems that the device may be a little out of spec. Has anyone else run into this issue? Is there an another option available out there?

Thanks in advanced.

I would expect the fred sled to have problems after the first round because its a single shot adapter. Or am i missing something?

Yes. Let me try to outline what is happening:

1) I'll put the device in place, place a round on it.
2) Close the bolt to load the round without any issues.
3) Fire that round then open the bolt to eject the spent case - everything works as intended so far.
4) I'll place a second round on the device - but when I attempt to close the bolt to load that round it noses down and makes contact with the breech thus preventing the bolt from going into battery and loading the round.
5) If I push up on the device -only then will the bolt go into battery and load the second round.

Does that make sense?

Aha! Now it makes sense.
Sounds like its getting jarred loose under recoil. Must not fit quite right. Maybe its never quite locking in all the way

It has just enough play that it won't feed right. It works if I pad the magazine release or the feeder with duct tape. But that may not work in competition.

Well, Sharp Shooter Supply tells me that I may have to shim the magazine frame (after I do a test). Has anyone ever done this and if so, have you ever had an issue with it affecting accuracy?