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indicating a barrel for chambering ?

Yes changing probe length messes with readings just a question have you or anyone else here after indicating range rod removed it and reinserted it and rechecked t.i.r.
 
double check is great but did you remove range rod and reinsert and check at two points or rechecked with an indicater at two points after using range rod which just sits on top of lands and what did you find when checking groove dia.'s
 
Your data, as you presented it, says the barrel isn't straight. Bending the barrel occurs when you use a 4 jaw chuck and a spider. since you have point contact at both ends, I wouldn't worry about that.

I would check again 1" 2" and 3" in on both ends. there is a reason you generally cut off a bit of the muzzle end.

--Jerry
 
Your data, as you presented it, says the barrel isn't straight. Bending the barrel occurs when you use a 4 jaw chuck and a spider. since you have point contact at both ends, I wouldn't worry about that.

I would check again 1" 2" and 3" in on both ends. there is a reason you generally cut off a bit of the muzzle end.

--Jerry
I never have see a straight bore in a barrel . Yes you can bend a barrel with a 4 jaw chuck and spiders . The bore is where you check the Straigness from . Larry
 
So I'm about to chamber up a new 7mm brux barrel and I'm a little stumped. Normally I just use a range rod with the proper fit bushing and dial in the barrel on the chamber/breech end with my mitutoyo .0001" Indicator to as close to zero run-out as I can get and don't worry about the muzzle runout. this was my normal way of chambering and I index the muzzle to 12oclock.

This time I used my mitutoyo .0001" dial with a 2.8" long tip. I dialed in the bored at the breech and then about 2.6" in to the barrel. I was dialing in on the groove and got it running damn near zero runout at both spots.





the muzzle end of the barrel was running about .050" out of round and you could visibly see the barrel was way out of being concentric at the muzzle end.

so I grabbed my range rod and .0001 indicator and dialed the muzzle end into about .0001" runout



I then went back and checked the far chamber end and it was still running almost zero run-out. I then ran the long indicator into the bore about 2.6" and it had a measured run-out of +.0005" now.

SO what is the best way to go about this? I'm still learning and I'm not sure if I should chamber it with zero runout at the breech and 2.6" in or should I get the muzzle dialed in and the breech and don't worry about the run-out 2.6" in from there?

I found this link quite helpful. Good videos.

http://shortactioncustoms.com/videos-2/

Phil
 
Why is that?

Well the bushing that fits the range rod needs to be .0002" smaller than the bore to to be able to slip it in and the bushing needs to be about .0002 larger than the part of the rod it slides onto. I think that allows error there. Now if the bore isn't straight it will be leaning further. I'm not sure the rods are that straight after a couple uses. Try it as George said. I have and mine just stays in the drawer.
 
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Well the bushing that fits the range rod needs to be .0002" smaller than the bore to to be able to slip it in and the bushing needs to be about .0002 larger than the part of the rod it slides onto. I think that allows error there. Now if the bore isn't straight it will be leaning further. I'm not sure the rods are that straight after a couple uses. Try it as George said. I have and mine gust stays in the drawer.
I usually do not double check after chambering but I think I will add this to my protocol and see what shows up. Probably too late to fix anything but it will be interesting to see. Thanks Butch.
 
If I measured my reamed chamber and it showed runout. Can you explain to me what could cause this? I think it would be very difficult to produce run out.

Butch,

A few things come to mind. Curvature in the bore, tailstock alignment issues, reamer not cutting on all flutes, reamer with build up on the leading edge. Just things that I have experienced personally.

Paul

www.boltfluting.com
 
Butch,

A few things come to mind. Curvature in the bore, tailstock alignment issues, reamer not cutting on all flutes, reamer with build up on the leading edge. Just things that I have experienced personally.

Paul

www.boltfluting.com


Basically you are saying poor machine practice and improper set up would do it? I guess we need to determine what runout that you are speaking of as it can be a couple things. Are you speaking chamber runout to the bore-groove or your chamber has runout itself?
 
One thing that I did notice on Mark's video is that he is using a rigid setup. If you were slightly off center the reamer would act like a boring bar so to speak. So, with his setup, he should have virtually no run out. Just an observation.

Paul

www.boltfluting.com
 

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