Berdan primers can be tough for a mini to fire. Wolff makes a spring to help increase the firing pin force. Might or might not help. The springs are easy to fine on the net, plus on youtube there is a video showing a easy way to install the spring. I have a spring on order myself for a mini 30. It won't light up my berdan primed ammo. I am going to try the spring, hopeful it will work, if not I will see what a gunsmith can do for me.