.50 cal plastic gas checks

[AR-15 Cowboy]

I just started casting boolits for my muzzleloader. .50 R.E.A.L. I had previously been using Aerotip .50 cal but they are way too expensive. The Aerotips have a plastic like gas chek. Is there anywhere I can buy those. The R.E.A.L bullet (Rifle-Engraved-At-Loading) is supposed to not need it, this is why Lee molds says use only pure lead to cast them so they engrave better. But I haven't had that kind of luck. I'm new to the group here so forgive me if I missed any earlier discussions about this. Thanks guys.

[subsonic]

Have you seen the "sub bases" that are basically like gas seals for .50 cal sabots? They use them in Savages with smokeless to avoid destroying the sabot holding the bullet.

They look like a sabot with the petals removed. Which also would probably work.

[groovy mike]

Sounds like I should get some for my 500 BPE. Any idea who sells them?

[subsonic]

http://muzzleloadingbullets.com/muzzleloader_magnum_sub_bases.html

I'm sure they're made by someone who makes sabots.

[subsonic]

I should clarfiy that these are designed to fit into the base of a sabot. They ae not really a "gas check", so you're on your own using them that way.

Over powder wads would probably do as well and be cheaper.