Tuner,? about lugs

kart racer · August 24, 2007, 06:47 PM

Why are the back edges of the lugs on tanfoglios beveled?They have basically the hi power setup.Is it becuase of the cam design?The lockup on my examples are tight.Just wondered why they did it and 1911's didn't.

WESHOOT2 · August 26, 2007, 08:06 AM

so flanging does not occur (which leads to wiring).

**Unclenick** · August 27, 2007, 06:29 PM

. . . which leads to wringing (of the hands).

K.R., it is a standard step in fitting up a 1911 to take a file or scraper and add beveling to a barrel's locking lugs edges. This guarantees smooth meshing of the barrel lugs with the slide lug recesses, and avoids the problems Weshoot2 mentions; peening of the lugs to create a wire edged flanges that can separate and/or cause jamming.

When you consider the angle of a 1911 barrel in lock-up, you realize that only one lug bottoms out in its recess in the slide and that the faces of the back edges of the barrel lugs don't meet the recess partitions squarely. They were made the way they were for practical compromises to do with machining processes available in 1911. If J.M.B. were alive today, I have to believe he'd have been all over the possibilities for CNC machining, and would have done it a bit differently in some details.

August 24, 2007, 06:47 PM	#1
kart racer Senior Member Join Date: April 23, 2005 Posts: 175	Tuner,? about lugs Why are the back edges of the lugs on tanfoglios beveled?They have basically the hi power setup.Is it becuase of the cam design?The lockup on my examples are tight.Just wondered why they did it and 1911's didn't.

August 26, 2007, 08:06 AM	#2
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	I file mine so flanging does not occur (which leads to wiring).

August 27, 2007, 06:29 PM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,742	. . . which leads to wringing (of the hands). K.R., it is a standard step in fitting up a 1911 to take a file or scraper and add beveling to a barrel's locking lugs edges. This guarantees smooth meshing of the barrel lugs with the slide lug recesses, and avoids the problems Weshoot2 mentions; peening of the lugs to create a wire edged flanges that can separate and/or cause jamming. When you consider the angle of a 1911 barrel in lock-up, you realize that only one lug bottoms out in its recess in the slide and that the faces of the back edges of the barrel lugs don't meet the recess partitions squarely. They were made the way they were for practical compromises to do with machining processes available in 1911. If J.M.B. were alive today, I have to believe he'd have been all over the possibilities for CNC machining, and would have done it a bit differently in some details. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle