indicating a barrel for chambering ?

[Danny1788]

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?

 

[Danny1788]

I also use a floating reamer holder and I chamber the entire chamber with a finish reamer and coolant flush system through the muzzle.

 

[savagedasher]

Just ask your self what is your doing
Chambering so do it straight Down the bore.
Larry

 

[Danny1788]

Does .050" runout at the muzzle end seem excessive though? I haven't had that much runout on the muzzle when I dialed barrels in before for chambering

 

[savagedasher]

Does .050" runout at the muzzle end seem excessive though? I haven't had that much runout on the muzzle when I dialed barrels in before for chambering

No not at all Larry

 

[tightneck]

Say what?

Just ask your self what is your doing
Chambering so do it straight Down the bore.
Larry[/QUOTE

 

[savagedasher]

Say what?

Chamber it straight down the bore I think he said he was chambering . Larry

 

['Freak]

Thinkin’ if you want the chamber’s centerline to follow exactly the bore’s centerline then both ends of the bore should be made to read as near zero runout as can be.

 

[savagedasher]

Thinkin’ if you want the chamber’s centerline to follow exactly the bore’s centerline then both ends of the bore should be made to read as near zero runout as can be.

Correct that why you insert a rod in the bore near the chamber end and dial the rod in perfect . But you also reverse the process when you crown and thread for a brake .
If anything I would worry more about the crown end . If the brake isn't on straight it won't shoot.
Reamer's have a pilot .
Larry

 

[Shrek]

If I understand correctly you want to zero out the chamber end so the bullet starts in aglainment and then thread and time it so that the muzzle end is indexed up or down so that the barrel harmonic doesn't throw random fliers. Am I understanding this correctly ?

 

[savagedasher]

If I understand correctly you want to zero out the chamber end so the bullet starts in aglainment and then thread and time it so that the muzzle end is indexed up or down so that the barrel harmonic doesn't throw random fliers. Am I understanding this correctly ?

I don't think indexing has anything to do with harmonic Index it the barrel is the direction the barrel is pointing in relationships to the action . Larry

 

[Shrek]

I think I have the concept. I needed to clarify that I was talking about threading the tennon on the action end to index the muzzle up but zero and thread the muzzle end in aglainment with the bore for the break.

 

[savagedasher]

I think I have the concept. I needed to clarify that I was talking about threading the tennon on the action end to index the muzzle up but zero and thread the muzzle end in aglainment with the bore for the break.

That is how I would want it .
Many of guns I have seen a break put on and they didn't shoot . Never have I seen one when straight with the bore that didn't .
Larry

 

[Eddie Harren]

That is how I would want it .
Many of guns I have seen a break put on and they didn't shoot . Never have I seen one when straight with the bore that didn't .
Larry

Larry, it's "brake". If you're going to be the authority, get it right!

 

[Gundoktr]

Larry, it's "brake". If you're going to be the authority, get it right!

Good one and "...your..." rite

 

[hogpatrol]

 

[geo.ulrich]

Correct that why you insert a rod in the bore near the chamber end and dial the rod in perfect . But you also reverse the process when you crown and thread for a brake .
If anything I would worry more about the crown end . If the brake isn't on straight it won't shoot.
Reamer's have a pilot .
Larry

Larry has it right get chamber end as straight as possible then turn around and do the same the .050 tir is not an issue when you straightened it out you induced chuck strain..George

 

[Danny1788]

Got it figured out. I was my dial indicator by adding the long stem I was not getting accurate readings. I went back to short stem and all the problems went away.

Guess ill just stick with my normal setup using a range rod from now on.

 

[ridgeway]

Get a long stem Interapid...

 

[savagedasher]

Got it figured out. I was my dial indicator by adding the long stem I was not getting accurate readings. I went back to short stem and all the problems went away.

Guess ill just stick with my normal setup using a range rod from now on.

Range rod is fine . The other is good also.
Larry