There was a report in the American Rifleman on this practise many years ago. Pressure teting was done at the time & amazingly the pressure was atually lower than an uncut shell. This paractise was however still strongly advised "AGAINST" as there was no guarantee of consistency & of course the possibility of bulging in the choke area. This test was done with shells having card & filler wads. The hull was cut completely through over the filler wad so it was held together strictly by the wads. I seriously doubt a shell with plastic wads would stand up to this paractise & be able to be carried for use.
