First rule of shooting
Never and I repeat never shoot someone else's reloads. If a reload is out of specs, it can and will harm a gun when it is shot. Without seeing the rifle it is very hard to diagnose what happened, but it could simply be that a piece of the case was shaved off somehow or if it was a hot load, brass could have flowed and caused the problem. Either way, like Mr. Watson said, either take it to a smith or let the folks at Marlin take a look at it. I would suggest a decent smith if one is close by but the folks at Marlin are fair folks to deal with, but at times are busy as well as a lot of smiths are at this time of the year.
Always shoot either factory ammo or ammo that you yourself loaded that was either loaded into a brand new case or one that was shot from your gun. Your buddies gun could have excessive headspace or he might not have headspaced it correctly to begin with. He might have loaded it with the wrong powder or he could have overloaded the round. There are just too many things that can go worng when you try a reload that someone else worked in another gun. Please don't ever do it again.
