Best Hunting scope Under $500 for Vulcan .25?

Hi - I am more familiar with AR optics for cqb and not much about Air gun optics. I am looking for a buy once scope for my soon to be Vulcan .25

I take it the Airguns need more ranging and some like lots of magnification. My purpose is sub 100 yard hog hunting in all kinds of weather with some squirrels as they present themselves. Less than $500.

Gotten my choices down to the following:
Nikon PROSTAFF 5 4.5-18X40 Matte BDC
Sightron SII 3-12x42mm Big Sky (or 3-9x)
Leupold Mark AR MOD 1 4-12x40mm

Appreciate any thoughts, suggestions or tips?

Thanks
 
"jmdesignz2"I thought the Frontier (made in Japan) was discontinued? Read some bad review about the higher end Hawke's - how's their warranty service?
The Frontier 2.5x15 TMX. Have not had any serious issues with any of my Hawke scopes. But everytime I contacted them they always offer to have the scope shipped to them to take a look at.... then I hang up!

http://www.hawkeoptics.com/frontier-riflescopes.html
 
any hawke, frontier 2.5-15 would be a great choice. I use the lower priced Nikko Sterling 4.5-14x50 Panamax for a wider view when hunting. The scope looks great. good finnish on it. Glass is okish. Bright but could be clearer at 14x. Tend to do my hunting at 6-9x. Its also fairly light. Hawkes will weight more.

Before i picked up the Nikko i was looking at the Sightron sII myself. The forums say is a solid product too.

Not sure I would shot hogs at 100 meters with a .25 vulcan.