Fusion Firearms Gunsmithing Carry Cut installation jig. This is a drill fixture for use on all brands of Carry cut style mainspring housings for 1911 style pistols. This jig is precision CNC machined from High carbon alloy steel and heated-treated then Nitro Carburized for many years of service. This Jig incorporates a longer clamping wheel base being 3-inch-long, the fixture/ jig stabilizes easily on parallels in a milling machine vise. Easy to use; a) Clamp parallel in vise b) With a mainspring housing pin clamped in the machine chuck. locate pin center to top hole in fixture(A dial indicator can also be used) C) Orientate and slide the frame on fixture rails and pin frame with mainspring housing pin in place. D) Center-drill, Pre-drill and then ream newly located hole for carry-cut mainspring housing. Now you are ready to assemble the Carry-cut mainspring housing and complete the machining/blending of the assembly. This fixture can be used over and over again. These are Top Quality Fusion Professional Series Parts. Made from the best materials and processes available in today's market. This is one of our most popular hammers. Made in the USA.