Hop-up, (High Operation Power Up), is the back spin trajectory of an BB pellets. By adjusting the Hop-Up, you can increase their range and accuracy of your GBB and VSR-10. As the pellet makes its way through the hop up bucking, the friction creates a back-spin, allowing the BB to go on a straighter trajectory. Airsoft Surgeon has released this "concave" shape bucking which will provide the most effective hop-up.
Using heavier BBs and adjusting the hop up accordingly it will have a remarkable increase in range. The reason being is that the long contact patch nub inside doesn't readjust itself to fit the BB's profile as it gets squeezed through the bucking, allowing for a steadier passage way, which in turn allows the pellets to fly straighter and farther.
The inner diameter of the Airsoft Surgeon hop up bucking is smaller and tighter than any existing hop-up rubber, so it will be more air-tight increasing the fps.
Ideal for 280 to 400fps GBB / Sniper Rifle, to get the best performance. Airsoft Surgeon recommends using the best quality hop up chambers and BBs.