The posi lock works,no one has copied it because it is patented,although Pentax has made a version under liscence from Burris.
One of the guys here who is a booking agent or PH in Africa has posted a lot about how well it works on his big bores. I don't know anybody who has not had good results from it.
E, have you ever used a scope with posi lock on a big bore?
I have and I'm happy with mine.
Britt
