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Post Posted: Mon Mar 07, 2011 11:07 pm 
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Here are the photos that I promised to take in another barrel crowning thread:

1. Remove lathe chuck, install the collet adapter, collet and arbor. I use a 5MT to 5C adapter on the spindle and a draw tube through the headstock to tighten the collet. On my lathe I had to turn the OD of the collet adapter down so I could install the chuck on top of it.

The arbor is used to center the chamber end of the barrel. It's a length of 1/2" drill rod that I turned the end down to a very small taper so the barrel lands will center on it. There is a step behind the taper that is turned down small enough to clear the chamber. Originally I was going to center off the chamber but decided that using the bore would more likely be on center. I don't know if there would be enough error to make a difference in either method.
Image

2. Install the 4-jaw chuck. Loosen the collet, extend the arbor and leave the collet loose.
Image

3. Install the barrel centering fixture in the chuck. This doesn't have to be perfectly centered because it has adjustment screws to center the barrel. You'll notice that my lathe is not as clean as Jerry's lathe :mrgreen:

Insert the chamber end of the barrel into the fixture making sure that the arbor goes into the chamber. Push the barrel and arbor back until only a short length of the barrel is extending past the fixture. Tighten the collet so the arbor can't move and then adjust the screws until the bore is centered.

There are several ways of indicating the center of the barrel. I put a pin gage in the bore and can quickly adjust it to about .0005 run out or less, then I remove the pin, put the indicator needle inside the bore and finish centering the barrel while indicating on the grooves.
Image

5. In this case I am going to shorten the end of the barrel until it is flush with the slide (it's a 4" Kimber with a bull barrel) so I take light facing cuts until I remove the required amount.
Image

6. I'm cutting a 45 degree deep crown so I've adjusted the lathe's compound to 45 degrees. Using a small sharp boring bar, I cut the crown to the desired depth. I make my last few passes using very light cuts and "pulling" the boring bar so it's cutting from the inside to the outside. If I "pushed" it into the barrel, which is how a boring bar is normally used, it would probably leave a burr at the edge of the bore.
Image

7. The rest is hand polishing. I'll start out with rolls of 320 grit emery cloth, polish the face of the barrel while the lathe is turning, and work my way up with progressively finer grits. After that I'll take a small felt bob that is charged with polish, hold it in a pin vise and put a bright polish on the muzzle. Remove the sharp edge on the outside of the muzzle and it's done.
Image

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Dave Berryhill
Berryhill Custom Guns, LLC

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Joined: Sat Feb 26, 2011 2:48 am
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Location: Northern Virginia

Post Posted: Tue Mar 08, 2011 1:09 am 
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Thanks for showing the swarf Dave...I get real inferior feelings looking at Jerrys photos. I know he does work but the pictures are SO misleading. :lol: :lol:
Nice tutorial. Now I need a big shop, a lathe, mill, tooling....I can dream big!
Joe

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Post Posted: Tue Mar 08, 2011 4:06 am 
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Hmm the barrel and slide looks oddly familiar! Great "how-to" Dave. Now I can see the time and precision you put into flush cutting and crowning my barrels.

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Post Posted: Mon Apr 25, 2011 4:46 pm 
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Great write up Dave thanks. I need to get a lathe and do two of my barrels. Trying to figure out how to do it in the mill without a 4th axis.

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Frank Ramsden

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Post Posted: Thu Dec 08, 2011 3:41 am 
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Dave, is there any difference in what you have posted here and what is referred to as a "Match" crown? Are the terms "match" and "correct" simply interchangeable? Thank you.

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Post Posted: Thu Dec 08, 2011 4:47 am 
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Heck!
Nothing to it.
Almost as easy as doing it using a Dremel.
:D

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Post Posted: Thu Dec 08, 2011 6:10 pm 
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D.I.Y.Guy wrote:
Dave, is there any difference in what you have posted here and what is referred to as a "Match" crown? Are the terms "match" and "correct" simply interchangeable? Thank you.

I don't know if there is any true definition of a "match crown" other than one that is properly done. These days an 11 degree crown angle seems to be what the guys who build true "match" pistols are using.

I don't dismiss the claim that an 11 degree crown is inherently more accurate than any other angle but for the intended purpose of of the pistols that I build, very few would be able to tell the difference. If the barrel is set up so the bore is concentric with the axis of the lathe and the crown is carefully cut at any angle, it would probably be more accurate than a poorly cut crown that is 11 degrees.

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Dave Berryhill
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Post Posted: Thu Dec 08, 2011 7:04 pm 
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Thank you Dave. I thought that was the case but I wanted to be sure. Appreciate your time.

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Post Posted: Thu Dec 08, 2011 11:00 pm 
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Great Post Dave thank you for passing this along.

I have a couple questions about your set up.

Is this a:

D1-4 spindle nose?

8" 4 Jaw?

Is that a standard (lever) type collet closer?

Is the barrel fixture aluminum and did you make it?

Finding the long allen adjustment screws might be harder to find than turning out the fixture!

Thanks again for all the info.

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Ray

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Post Posted: Fri Dec 09, 2011 1:34 am 
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Yes to all. I had to turn down the outside of the MT5 - 5C collet adapter a bit so the chuck would fit over it. It wasn't as hard as I thought it would be and a carbide tool bit easily handled it.

IIRC, the screws with the swivel pads are from MSC. The screws and swivels are sold separately. You could probably use standard socket head screws and place some aluminum (or other soft metal) shims between the screw tips and the barrel. I also drilled and tapped a second set of holes in the aluminum cylinder. Instead of using a pilot in the lathe collet to center the rear of the barrel, you could use two sets of screws and center the front and rear independently. One of these days I'm going to get a range rods to use when centering the barrel:
http://www.pacifictoolandgauge.com/prod ... #indicator

Many thanks to Jerry Keefer. I've adapted many of the techniques that he taught me.

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Dave Berryhill
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