Forty eight 60 gram single shot shells. The best two brands that I have heard of from the pryo forums. Each is a single shot and decent.
Built a rack for my 10 HDPE tubes with plugs. It is solid as hell and will work awesome. The HDPE will mushroom if there is a failure instead of shooting shrapnel.
Used the carbon fiber tubes and the HDPE ones fit in a rack and they will be secondary set away from the crowd just in case there is any sort of failure.
Both mortar racks are on a foot wide piece of treated 1 inch pluwood and are nailed and screwed like tanks.
Swing by if ya want.
Below are the posts of last years boards….
This one was after the Uncle Sam Jam at Oak Lake on the 3rd of 2012