Filipinos are pretty ingenious people, check out their silenced M3 Grease Guns, their backyard gun shops rival those made in Pakistan and India. Check out the .50cal bolt-action rifles captured in Zamboanga City complete with optics, bipods and muzzle brakes. That being said, I still wouldn’t want to risk shooting it.
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I’ve used/shot quite a few guns from Davao and can honestly tell you they shoot like gangbusters. The S&W Model 10 copies are fantastic. The machining is great. The only worry is suspect materials, but a reputable gun maker usually goes all out since his reputation is riding on it.