Definitely an air soft rifle stock. Like a JG BAR 10 style. (Kinda Rem 700 style). Hop means Hop Up like it puts pressure on a rubber piece in the barrel that when the airsoft bb goes past it it puts back spin on the BB and that makes it fly further.
Gun:
Shop The JG VSR-10 is the closest replica to the Tokyo Marui VSR-10 bolt action sniper rifle popular for it's upgradeable design, trigger box design and after-market part availability. Each JG VSR-10 from Evike.com is equipped with an adjustable metal trigger box, a 400+ FPS high power spring...
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The magazine cut out is another reason I'm sure that's it. Has a little ejection button, right? See how the mag has the same side cutouts?
Magazine:
Shop ... , Accessories & Parts, Airsoft Gun Magazines, Sniper Rifle Magazines
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