So is not safe right reload them ?Hopefully one of our very experienced guys will weigh in, but the short answer is, "yes". You will have increased the amount of flash that gets through to the powder and weakened the brass under the primer. I'm not sure I'd even attempt to fire such a case and if I did, I'd start with the lowest recommended charge weight. I'd also chronograph those loads and see if they are producing more velocity than they should.
Best advice is to stick with one system or the other.
I think that boxer primers are slightly smaller than the berdan kind. So a boxer may not fit tightly enough in a berdan pocket to seal against gas blowback. It could be dangerous to your face.
My mistake i was telling you about the scopeHere, I found the Berdan brass to Boxer conversion tutorial on another forum:
It has pictures and everything. Hope it helps.