So I ran into an issue with my build. I have a older 110 pre accutrigger that was a 270win blind box. I am converting it to a mag fed 300wm with a MDT TAC 21 chassis. The problem I ran into is the magazine cannot seat all the way because the opening in the bottom of the reciever is not long enough to allow the magazine to be inserted into it. Is this a common problem when doing this type of conversion? Did savage make changes to the bottom opening in the reciever? I have the skill/ability to put the receiver into a mill and open it up some to allow the mag to work, any known problems in doing that?

Another small issue I have is the rear action screw hole is pretty severely cross threaded in the first couple of turns, so much so that it cannot be chased with a tap from the bottom. Do I drill out the first couple threads and use what's left? Another method i seen was drilling a hole just big enough in the top of the action directly inline with the action screw hole and chase it from the top. Which do I do?