12GA shotgun shells

[judgment_arms]

Hey all, I’m new here so forgive me if I state the obvious or sound dumb.
Ok, I’m working on a new idea and I just discovered that a 12GA shotgun shell fits perfectly in a piece of 3/4” SCH 40 PVC.
I’m tring to make pneumatic shotgun and I was thinking of using spent(fired) shells and knocking out the primer and reloading them with just a wad and airsoft BBs. Then you stick it in a piece of 3/4” SCH 40 PVC and you have the air blown in through the hole left from removing the primer (which just so happens to be ¼”). And that’s as far as I’ve gotten so if you have any ideas on how to get this thing to work please tell me.

[shadowghost21]

Make a regular air cannon, make a breech loader and put in your shell filled with bbs and fire. I have a similar gun but I made the shell, and the gun is a nerf rocket launcher (modded of course). But this seems to easy to answer maybe I didn;t understand your question?

[judgment_arms]

that may work, but it would probably have vary pore performance.
what I was saying is you feed the air through the hole where the primer whent. i'm going for a slide-action type scatter-gun.
thanks for responding