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Thanks to all the good information on this forum and in several books, I've decided to go forward with teaching myself to chamber rifle barrels. The first steps will be making the tooling I can make myself, buying the rest, and then going to work on the first barrel. My first successful step is completion of the Cat-Head to go on the outboard end of the lathe spindle. The lathe is an Andes 12" x 36" gearhead with a 1-5/8" spindle bore. Since this attachment won't have much load on it, I machined the body from a piece of 2-1/2" aluminum rod stock I had in the metal archive. I machined it to fit over the spindle end with a shoulder in it to take down to spindle ID. The shoulder controls how far it goes onto the spindle. I used 5/16-18 set screws that will clamp it to the spindle. I made my own 1/2"-20 centering bolts from some 5/8" CRX hex stock (also from the metal archive), and tipped them with brass tips made from some 1/2" square brass bar stock from ... the metal archive (where else?). All this cost me was a very pleasant afternoon in the shop and a slightly lighter scrap pile. I'm about to make up a reamer pusher, a bracket to clamp to the tail stock ram for a dial indicator, barrel vise, and some other doodads. Anyway, I wanted to show the Cat-Head to somebody, so here is a picture of it. ![]() | ||
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One of Us |
Fitch, This is my method. I use copper instead of brass, it is softer and holds better. You asked for it and here goes. I do not claim that there are not better ways out there and I like Rusty Stud have altered out methods through the years. A new rookie with just a little lathe experience can do this in 4hrs or less. I have done several and it takes 2-2 1/2hrs. I chamber in the headstock as it allows me to do all the chamber work without moving the barrel and it is done in one setup. As stated before, I have 2 catheads and all the screws in both have 1/4" copper inserts. It gives grip and allows the barrel to pivot when indicating. I have a set of Deltronic pins for each caliber that I chamber. That is 7 sets of 25 pins ea. They come in .0001 increments. For example Shilen targets .237 as their mean bore dimension for 6mm and you can get the same from Bartlein and Kreiger. My middle pin is .237. I have 12 pins below that number and 12 above. It gives me a range of .2358-.2382. After cutting about 1 1/2" of the breech end and initially 1" off the muzzle end I set it up in the lathe. The breech and muzzle will be a little sloppy from the lapping and that is the reason for cutting some off both ends. I indicate a slip fit pin on either end until a .0001 indicator doesn't move. I drill the bore with a drill that is approx. .060 under the diameter of the shoulder of the cartridge. At this time I can put my 513-504 Mitutoyo .0001 indicator into the drilled hole and then I indicate the grooves to .0001 and check the heights of the lands at the same time. If the land heights vary .0002 or so the barrel goes back. I am indicating the throat, the first thing the bullet sees. I cut the tenon to diameter to size and length. I thread and check with my thread mike. I have both carbide and tool steel thread cutting tools. I personally prefer tool steel. With my tenon turned and threaded I turn my attention to chambering reaming. I initially put my reamer in the tailstock and indicate my compound to the exact same angle as the body of the reamer. I use a short stiff carbide boring tool and taper bore in the compound to within .010-.020 of the shoulder diameter and .100" short of finished length. I do not use a chuck or floating reamer holder any longer. I made a reamer holder that slips over the reamer and has a point on the back with a .030 radius on it. It has a handle that screws into the side of it and it clears my ways. I made a pusher to fit in the chuck. Just a piece of stainless with a 1/2" shank and a 1" flat face. The flat face bears on the radius of the reamer holder and allows it to float if needed. Crowning is the same basically, just turn the barrel around and repeat. I do both my hunting rifles and benchrest rifles the same way. Are we anal in our setup, probably, but we feel better when we are done. Before you take your setup apart, run your tenth indicator back into the throat and check your setup after all of your machining is done. If you did a good job your indicator will tell you. This is 2 finger typing and I am tired. Comments are welcome. Butch | |||
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One of Us |
Thanks for the input. I've seen your setup in pictures in other threads. It looks good. I need to look up the rods you describe. It would seem they are better than the conventional range or indicator rods, though they may be beyond my budget. The way I'm planning to do it, the cat-head will apply no torque to the barrel. My initial plan, subject to change, is to make a aluminum ferrule that looks sort of like a wedding band, slotted on one side, to go around the breech end of the barrel and be chucked in my 4J chuck. I've seen that on here some place - that's where I got the idea. I plan to use an indicator or range rod as appropriate to align the last three inches or so of the bore centerline with the spindle centerline - basically equivelant to the approach in the Grizzly video. I'll make adjustments on both ends (chuck and cat-head) to do it. I'm doing it that way because it is the only way I've seen that will result in an initial bullet path exactly down the centerline of the bore it is entering. I plan to do something similar, with the barrel reversed for crowning, to make sure the plane of the crown is exactly orthogonal to the centerline of the bore where the bullet is exiting. I will doubtless discover refinements as I go along, but that's where I'm going to start. The first barrel probably won't have the benefit of a power flush, or removable bushing reamer pilot, though I can see how that is "the" way to go. | |||
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One of Us |
Butch, I've seen pictures of and read about this chambering method and I'm not sure I completely understand. After you drill then taper bore the initial hole what keeps the reamer centered in the hole? When the reamer initially starts in the hole the pilot will not be in the bore yet right? So is it just the fact that you start with a hole that is true/straight with the bore that the reamer stays straight until the pilot reaches the actual bore? I'm going to cut a chamber next week and am thinking about trying it, thanks! | |||
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One of Us![]() |
Very nice tool Fitch ! Don't take the chip ! | |||
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One of Us |
kwk, I want the reamer to follow the bored hole as it is coaxial to the spindle bearings. The bore may not be straight. Yes, the bushing does still reach the bore. I use a loose fitting bushing. I realize this is contrary to a lot of peoples thinking. That is OK with me. I have chambered several different ways and found this to be the best way in my own mind. Butch | |||
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One of Us |
Thanks Butch, the part I couldn't get my mind around was the reamer pilot reaching the bore. I just didn't think it would reach, so I think I understand it pretty well now, I may give it a try. I've got a 6.5 cal Lilja I'm going to fit up this week. | |||
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One of Us |
And a very nice, in-focus picture it is... | |||
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One of Us |
That is an excellent photograph, really exceptional. Don | |||
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