I just added 2" to my tac 15 I stock for little $ and was easy.
I took a piece of 1" 1/8 deck board then scribed the stock end and cut
with a sabre saw then drill pilot holes on each side of the stock butt.
then attach the wood to the stock end and screw . Then use a 3/4 " board
and cut...
Hunting in a tree stand is great with my tac 15i .
Just remember to grip the pull up string good.
I lock and load once up in my stand and also unload
before going down. Works great with shooting bar.