What I learned about dialing in a barrel

[DaveTooley]

It's easy to change bushing on a Manson reamer. It took me maybe 10 years to figure it out. You need a very small screwdriver as in the kind you use on glasses. Place the butt of the reamer in the middle of your chest. For right handed people take your left hand and place your first finger under the E clip. Catch the left edge with your thumb nail. Push the right side down with the screwdriver. Your finger controls the travel of the clip. I almost never lose one. You could probably make a forked pusher and do the same thing. Got any broken screwdrivers laying around? "until i made a little tool"

 

[DaveTooley]

Maybe I'm not understanding, or it isn't obvious in the picture, but how do you get TIR to change in 2 places in a 2 or 3" section of barrel with a single point of contact, be it with a spider or chuck?
Using a long stem indicator in the throat to get it true makes sense. Using the same contact as a pivot to get the breech true makes sense. Are you changing and/or chasing that relationship from throat to breech with an outboard spider at the muzzle end of the barrel?

Yes. Those that do it that way move the muzzle to get the breech end aligned in two places.

 

[338 Mollett]

I took a butter knife and found an area that matched the diameter of the grove then ground a v in it ,but I still hate those clips.

 

[DaveTooley]

These days I'm not particular about bushing size so I just leave an undersize bushing on each reamer.

 

[hoz53]

It's easy to change bushing on a Manson reamer. It took me maybe 10 years to figure it out. You need a very small screwdriver as in the kind you use on glasses. Place the butt of the reamer in the middle of your chest. For right handed people take your left hand and place your first finger under the E clip. Catch the left edge with your thumb nail. Push the right side down with the screwdriver. Your finger controls the travel of the clip. I almost never lose one. You could probably make a forked pusher and do the same thing. Got any broken screwdrivers laying around? "until i made a little tool"

yes i took a little piece of metal the thickness of the e clip slot and made a little notch in it like you say. ill try youre method though. Thanks Dave

 

[butchlambert]

These days I'm not particular about bushing size so I just leave an undersize bushing on each reamer.

I do the same Dave as after taper preboring, I do not want a bushing make my reamer wander and cause the base of the chamber to be slightly oversize.

 

[hoz53]

I took a butter knife and found an area that matched the diameter of the grove then ground a v in it ,but I still hate those clips.

about the same as i did

 

[DaveTooley]

38 years ago when I got started I thought a tight fitting bushing would alleviate the need for a properly setup barrel . It's just the opposite. I learned from guys who didn't have lathes with a large enough spindle bores to chamber through the headstock. With my first lathe I had that option and soon learned that a properly setup barrel was about all you needed to do pretty good work. Subtle details would come later. Whether you use the muzzle and throat or two points in the breech you'll get good chambers. The reamer is going to the center of the bore. Every once in awhile after I get done with a chamber I'll put the reamer back in and run a tenth indicator on the outboard end of the reamer shank. I've don't get over a few tenths movement. Sometimes almost zero. That's in a reamer that is at least 5 1/2" long. Seems pretty good to me. Even better pretty simple to do.
Not trying to start anything here but as far as axial alignment we're only talking about the length of the bearing surface of the bullet. No matter which method you use the chamber is probably in better axial alignment than the bullet sitting in the cartridge case. As always YMMV

 

[DaveTooley]

I do the same Dave as after taper preboring, I do not want a bushing make my reamer wander and cause the base of the chamber to be slightly oversize.

Also it can and will force the throat off center at the same time. Wobble on one end means wobble on the other end.

 

[hoz53]

38 years ago when I got started I thought a tight fitting bushing would alleviate the need for a properly setup barrel . It's just the opposite. I learned from guys who didn't have lathes with a large enough spindle bores to chamber through the headstock. With my first lathe I had that option and soon learned that a properly setup barrel was about all you needed to do pretty good work. Subtle details would come later. Whether you use the muzzle and throat or two points in the breech you'll get good chambers. The reamer is going to the center of the bore. Every once in awhile after I get done with a chamber I'll put the reamer back in and run a tenth indicator on the outboard end of the reamer shank. I've don't get over a few tenths movement. Sometimes almost zero. That's in a reamer that is at least 5 1/2" long. Seems pretty good to me. Even better pretty simple to do.
Not trying to start anything here but as far as axial alignment we're only talking about the length of the bearing surface of the bullet. No matter which method you use the chamber is probably in better axial alignment than the bullet sitting in the cartridge case. As always YMMV

Thats some great info Dave Thanks

 

[jkohler]

The last hand full of chambers I’ve cut have been with out a bushing at all. I’ve pushed the reamer with a center for most of the chamber then switched to my pusher. I’ve been more than happy with the results. I have drilled and bored out most of the chamber on them.

 

[Dusty Stevens]

I do the same Dave as after taper preboring, I do not want a bushing make my reamer wander and cause the base of the chamber to be slightly oversize.

But if the base is bigger your sizing die will have something to do

 

[LC Tikka]

After dialing the bore and ready to start the chamber, do any of you take a light cut for the tenon, this would give a large and lasting reference to check for movement during the work.
LC

 

[Papa Charlie]

When you say "Pre Bore" how deep do you go before switching to the reamer? My first assumption would be half way down the case body length and 0.010"-0.015" under size the smallest diameter on the case body, or am I totally off base?

Also, do you use a boring bar?

 

[Stan Taylor]

When you say "Pre Bore" how deep do you go before switching to the reamer? My first assumption would be half way down the case body length and 0.010"-0.015" under size the smallest diameter on the case body, or am I totally off base?

Also, do you use a boring bar?

I personally have never prebored, I don't really see the reasoning other than reamer wear.

 

[hoz53]

I personally have never prebored, I don't really see the reasoning other than reamer wear.

Yes -- im loving it Stan cause I hoped for a long time Id be able to get away with boring the whole chamber with a finish reamer and thats what i did for awhile. I only use my reamers for my own stuff so they dont get used alot. I think I may be headed to the Dark Side soon though and begin to Bore. Mabie even set up a flush system-Yikes
Can I be Saved?? I wanna know why Dusty doesnt use a flush system anymore?? Thanks for that piece of Info

 

[hoz53]

The last hand full of chambers I’ve cut have been with out a bushing at all. I’ve pushed the reamer with a center for most of the chamber then switched to my pusher. I’ve been more than happy with the results. I have drilled and bored out most of the chamber on them.

Youre tailstock and headstock center alignment must be good? You mean you push the reamer with a center that is in the tailstock with a wrench on the reamer? By a pusher you are talking about a floating reamer holder?
Thanks Jkohler u provide alot of good info on here.

 

[Alex Wheeler]

The freebore of a reamer is far more critical to wear than the body. Body wear is the last thing Id worry about.

 

[DaveTooley]

Most can't see the light.

 

[338 Mollett]

I'm wondering if guy's that have snapped a reamer prebore or not because I have a theory.I will wait for their answers on that one.Now every body wants to do barrel work with the best results on paper,let's say a barrel is machined absolutely perfect ,square to every thing,how much of that translates to accuracy?I've said many times a mediocre barrel machined to perfection will not win,not even be competitive,a good barrel will tolerate alot.So we have this barrel machined to perfection and yet for most shooters they full length resize.That should create a void between the case wall and the chamber introducing the bullet off angle.This does not apply to neck sizing BR guys who are like duck hunters that enjoy 20 below weather.But I would ask for the study of a good barrel with cases sized both ways.