Milling cut for ramped barrel
The two most predominant type of ramped barrels are the Wilson/Nowlin ramped and the Clark/Para Ordin ramped barrels. The required milling cuts are different for each, so reading the mfg instructions is best.
I have all W/N ramped cuts on several of my guns. I cut one frame for a W/N ramped cut only using a drill press, files, and hand tools since I don't have a mill. It took a lot of time, but it came out fine, and I use the gun for self defense. In my opinion, the critical element is to make sure the ramped barrel hits the bottom of the ramp cut and the top sides of the bridge of the frame at the same time, which dissipates the unlocking force over a broader area. Also, I like to make sure the bottom of the feed ramp is slightly into the mag area inside the frame when it is completely in the ramp down position. This brings the feedramp as close as possisble to the magazine and helps to prevent nosediving when bullets feed. I may cut back the bottom of the feedback a few thousandths so the mag won't bounce against the very bottom of the ramp. None of the magazines I have ever used feed the cartridges so they strike at the very bottom of the ramp, but more midway on the feedramp. My guns feed very reliably with all bullet nose styles, including JHP's.
Last edited by richpetrone; 02-10-2010 at 09:53 AM.