I shot a 338 with a tactcal IOR 6-24x50. They are ....just like everything....worth what you pay for.....The glass isnt the best so at full magnification the targets were not very clear. The adjusters didn't seem to be as smooth as I would of liked either......all in all it seemed like a very decent scope....and one that could put up with years of a 50's abuse but if you have something smaller then a 50 I woldn't recommend them.
I was gung ho on the IOR because of the Zeiss (schott) glass inside. However, once I bought one and realized what a POS it is, I swore never to touch one again. In their defense they are supposedly redoing their tactical line. I will let someone else be the guinea pig before I pick one up again.