Well, I think it would be a good idea to try either CCI Mag or federal primers, I really can not believe it will cure the problem 100% but it should help.
My ides on how long the touch hole should be is based on the fact that as close as some of us have been able to tell the Triumph and the Omega have in most instances for most people have been the best most reliable and most accurate with BH[ i certainly never shoot any half inch groups much less back to back before I started using it.
they both have a touch hole that is right at .15 long since the guns that don't have the 1/8 inch flame channel to a touch hole that's that short are the ones that have hang and miss fires that and a tight fitting sabot and some wad pressure are the only obvious differences. So when you try the hotter primers be sure you also have a tight fitting sabot[ as long as it takes both hands to push it down it should be tight enough] and lean on it once when its all the way down. Then if it were me and it still did not work well with BH I would carefully measure and take it down to as close as is practical to .15.
Just my thoughts on it. Lee