New From JP Rifles: Variable Mass Operating System (VMOS)
By Jeremy S.
The JP Rifles Silent Captured Spring (SCS) system, reviewed here, is one of my favorite AR upgrades. Tuning an AR to perfection is done by adjusting the balance of reciprocating…
The post New From JP Rifles: Variable Mass Operating System (VMOS) appeared first on The Truth About Guns.
Source:: Truth About Guns
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