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Ryan Songhurst you can epoxy the std mount on to stop it turning or drill a small hole under where the sling goes on the mount. Use a piece off the drill bit to make a pin and drill a small hole in...

I clicked your link, yes has a cheaper version.
The ball and lock system is the same as the extreme pod.

Tahr where did you get the $399 from his web says $599

All round I think the spartan javelin is one of the better hunting bipods on the market. If you want light, sturdy modernised Harris style then the tier one carbon bipod is exceptionally well made....

They are a bit different to a atlas. They were sold by solohuntr for years called extreme pod. I think hardy changed the leg a bit and gets them made in China.
The pic rail mount from aliexpress...