I have for sell SWFA SS 16-42 tactical 30mm that has been on a 308 win for about 150 rounds.
Here is the spec per the company
OK for .50 cal
There is a light ring marks on the body.
It is a great scope good clarity on the optics. I have had for about 6 month just looking to up grade to a Vortex Viper PST. My 308 win is going to my go to gun for everything now with the new load I found with 208 amax.
Asking $250 obo