Use yer supply of 00 buck for short range shooting & practice through a IC or cyl tube, Full choke usually sucks with 00 buck by scattering patterns.
Then go buy Federal 00 Buck Flite-Control shells, 3''-00 buck the lower velocity ones shoot the tightest patterns usually.
The tightest patterns come from Federal Flite-Control 2 3/4 00 buck LE with 8 pellets @ 1100 fps, made for law enforcement through cly/open- no choke.

I would have got him too but a Dad Blam snow flake hit me in da eye....