Hey, guys. Sorry so slow getting back. Just got the insert delivered today! Very slow delivery, but it is here! Note that I started down this road because the rifle is composed of 3 rifles, including a receiver with stripped out rear scope mount holes that ain't re-tapped in line. I'd have to open up holes in anything to go back there (I did fix the factory base to werk)... Anyway, spending real money on this one ain't happnin'!!! Don't like the way the front sight sits so low in the rear sight, so thought I'd try this. Thanks for the bit size. It looks good in yours. I'll let ya'll know how badly I bugger it up!