r/37mm

Coincidentally found that the plastic caps to these gallon water jugs at Target fit snuggly in my aluminum 37mm shells.

Should work well as pushers and to keep the powder charge in place.

They mic at 34mm.

Something I have been working on - long range smoke (100+/- yards) rounds in a ready to load refill format. Will still require hazmat shipping but pricing will be quite reasonable. 30 second smoke generation is the goal with these. Planning for the hulls to be darker subdued type colors with cap the color of the smoke.