If you can do it yourself by all means go for it. For others Gre-Tan is about as good as it gets.
They're so busy they have a notice on their website they are not taking on any new work.
I recently installed a M16 extractor in a 700 heavy barrel 308 for a local LE TEU person. He brought in the M16 extractor kit and the instructions said the barrel counter bore needed to be opened up per chambering. Advantage of the M16 type over the Sako type is the retaining/pivot pin, to me the advantage is lost when the counter bore has to be enlarged. Take your pick.
The M16 appeals to me in that how it's held in place is more posititve
but opening up the c'bore for the bolt can be tricky with the barrel still being in the action. Though it can be done. I've never heard of a Sako extractor coming out though.
