why?

[JT.]

if you use a floating pusher an reamer with the right pilot bushing
why do I need to dail in the barrel ?
the reamer follows the bore
so the chamber can be a little of center but there is some the play in the boltface
if the chamber is no more off center then the play I do not see any problem
so why dail in the barrel when using thise method ?
what am I missing here ????

 

[Bill Gruby]

A floating reamer set up will follow wherever the bore is. If it is off the reamed hole will be off. A floating reamer is not meant to make up for work that is not centered correctly, it just helps relieve any undue pressure a reamer can encounter. You dial in the work for accuracy.

"Billy G"

 

[Rbeckett]

Trust me you need to dial it in because the little errors all add up and create an grossly inaccurate piece. It might look good, but if you cant hit the target at 100 yards it instantly becomes pretty useless. Just another pretty thing in the gun safe or closet. so line it up and get it as accurately dialed in as possible. You will not regret the few minutes it took when you pop the eyes out of a rabbit on the run without missing at 175 yards. Just my opinion and hope it helps to explain the reasoning behind that point of view. Good luck and let us know how it works out which ever way you choose to go.

Bob

 

[Tozguy]

JT,

In my opinion you can't trust the pilot to keep the reamer in line with the bore TO THE LEVEL OF PRECISION required for an ACCURATE rifle.A pilot just doesn't fit that well. A floating reamer holder will do nothing to control the other end of the reamer. If the reamer starts cutting off axis it will continue off axis. The result will likely be an irregular chamber with the possibility of rifling damaged by the pilot.

Even if you dial the bore in very well and use a piloted reamer, there is a lot to be said for preboring before reaming so that the reamer BODY is guided in straight and concentric to the bore by the hole it is following.

 

[Tozguy]

so the chamber can be a little of center but there is some the play in the boltface
if the chamber is no more off center then the play I do not see any problem what am I missing here ????

That's a big 'IF'. The play in the bolt face might not be enough to 'accept' the offset of the chamber. Then what do you do?

 

[JT.]

it is just an idea .
another one is then if you set everything up with best possible dial in
cut out the chamber with a bore bar and then ream the chamber why use snug fitted pilots then ?

 

[dave2176]

Darrell Holland uses a drill bit as a rougher. Personally, if it was a one off just for personal use I would use my 4 jaw and out board spider and dial in both ends to less than .0005" using a guage pin in the bore. I would use the proper finish reamer to do the entire bore. If I intended to do several, I would order a roughing reamer from the same manufacturer such as Pacific or Clymer. I know that I probably can't shoot to the guns potential but I get satisfaction from doing it the best I can and I would know I short cut it.

Dave

 

[Rick Leslie]

I us a tight fitting gauge pin in the bore and dial in on that. This assures the bore is running true. I check the chuck end and the 'other' end and get the bore running as true as possible.

There are many reasons for dialing in the barrel. One is as stated earlier; accuracy. Not so much the accuracy you're trying to get with the barrel, but the accuracy of your work. You remove as many variables as possible during the building process. That way you have fewer bugs to deal with when you start looking for the other kind of accuracy.

Also, floating reamers can only do so much. The idea behind the floating reamer holder is to allow the reamer to freely follow the bore without undue stress from run-out.

And lastly, you can't get the mirror finish you need for a chamber with a boring bar. The reamer cuts a much better finish than a bar could ever achieve.

I actually short chamber all my barrel blanks in the lathe, then fit them to the action and finish chambering by hand.

 

[Tozguy]

it is just an idea .
another one is then if you set everything up with best possible dial in
cut out the chamber with a bore bar and then ream the chamber why use snug fitted pilots then ?

If you dial in and prebore then it is not so important to have a tight fitting pilot. Some don't even put a pilot on the reamer when the chamber is properly prebored.
When using other methods like chamber cutting between centers, the fit of the pilot is more important. Is this an academic discussion or do you have an actual chamber to cut?

 

[JT.]

thise discusion more "what if " just to let the ideas flow
before i make up my mind on the way i want to go to cut my chambers