None. The stock was inletted for this action so it was drop in other than making it left hand. It is a universal stock so it can be used for a left or a righty.

When converting it over to left hand I set the action in the stock without the bolt handle and marked the width. I used a small flush cut saw to go down until it was almost the same height as the right hand cut out. Then I took a die grinder and slowly went down until the bolt handle would not bottom out. After that I painted the area I cut out with some black paint.

It is a very comfortable stock and a great value. I will say that it will get a bedding job done because even when the action screws are tight the action has a little more movement than I like.