Airsoft Outlet NW have a review of the hybrid tightbore barrel from Modify:
The Modify Hybrid Tightbore Barrel is unique among airsoft precision inner barrels in that it uses a two piece construction. The base of the barrel is constructed of steel, while the barrel length is aircraft aluminum. The grooves on the base are designed to work in conjunction with the Modify Hybrid Hop Up Bucking, providing improved air seal. We’ve used a number of barrels before, and it’s no new thing to find a company trying to figure out a new way to do the same thing. We picked up a Modify tightbore to review and see how well they actually work in one of our AEGs.
In addition to the two piece construction, Modify has two other features unique to this barrel. One set of features are the grooves on the base. As mentioned, Modify includes a specialized hop-up bucking with each barrel. This bucking is designed with notches that fit in the grooves, ensuring an air-tight seal. The other unique feature is the o-ring stabilizer design. The tip of the barrel sports 3 grooves of different depths. With two included o-ring options, there are 6 barrel spacer diameter possibilities. These allow for a precise fit in any outer barrel, eliminating vibration and increasing accuracy.
