For the last three years my only misfire problem has been with Thunderbolts.
Now with the TAC 22 standards they did misfire in the SW22 until I had about 500 rounds through it. Now they also work fine in the SW22.
Thunderbolts misfire too much, are very dirty and leave an incredible amount of lead in my barrels.
I've got about 300 left to burn through and I fire ten rounds of them per 50 rounds of any other ammo. Then the cleaning is not so bad.