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Pre bore the chamber results?

Carl S said:
I always check the chambers with the bore scope and i no Mike definitely will when he gets them home.if there was any flaws he would be on the phone.if i didn't pre bore and use the muzzle flush system may be I would have marks on the rifling where the reamer potentially goes in on the piss and cuts off centre..may be I would if i used the reamer as a drill and not start it in a true pre bored hole.im not saying my way is correct but it works for me and it doesn't make the phone ring.Regards.
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The bore scope is why I switched to removable pilots many, many years ago , at least 25yrs. I was taught to drill and bore in gunsmith school (MCC 2yr program, grad in '93) those 30+ yrs ago. I built a muzzle flush before it was 'the thing to do', as I had seen a Pratt & Whitney 'dedicated chambering machine' (built on the same frame as the P&W single spindle rifling machine)

in the past that had, as factory equipment, oil through the barrel to flush the reamer. (that P&W dedicated chambering machine was of WW2 vintage). What I saw that was left behind by the fixed pilot, I did not like. And yes, I know how to set-up as I had 16yrs of 'job shop' machining experience before I enrolled in GS school. My phone rings often, wondering if I have time to.............
 
Alex Wheeler said:
Centerline of spindle rotation. A good thing if the right parts of the bore are too. A bad thing if they are not.
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Then, he should have said so! Concentric to the bore, the spindle, the turned diameter for the threads, the OD of the barrel shank? Should be all of the above except the barrel shank, unless it has been turned concentric to the bore. I've been machine since '74, didn't learn machining or chambering yesterday from U-tube. be precise when posting or relaying info.
 
shortgrass said:
Then, he should have said so! Concentric to the bore, the spindle, the turned diameter for the threads, the OD of the barrel shank? Should be all of the above except the barrel shank, unless it has been turned concentric to the bore. I've been machine since '74, didn't learn machining or chambering yesterday from U-tube. be precise when posting or relaying info.
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Why? We all know its concentric to spindle rotation. Thats all we really know even if he said otherwise.
 
Alex Wheeler said:
Why? We all know its concentric to spindle rotation. Thats all we really know even if he said otherwise.
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There are probably 100 guys reading these threads wanting to buy a lathe so they can 'chamber their own barrels'. 4-5 might end up setting a lathe in their garage or basement. Many don't know, so it's not "We all know its concentric to spindle rotation". Many come here to 'learn', I mostly come just for "kicks n giggles" and to see how many sacrificed the neighbors cat last week before they cut a chamber.
 
shortgrass said:
There are probably 100 guys reading these threads wanting to buy a lathe so they can 'chamber their own barrels'. 4-5 might end up setting a lathe in their garage or basement. Many don't know, so it's not "We all know its concentric to spindle rotation". Many come here to 'learn', I mostly come just for "kicks n giggles" and to see how many sacrificed the neighbors cat last week before they cut a chamber.
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Ok, I can see that point. I was only focusing on the guys posting which seem to all be doing this kind of work. To the ones reading, Id suggest getting off the gunsmithing forums and learn basic machine principals. Then the gunsmithing part will make sense.
 
Alex Wheeler said:
Ok, I can see that point. I was only focusing on the guys posting which seem to all be doing this kind of work. To the ones reading, Id suggest getting off the gunsmithing forums and learn basic machine principals. Then the gunsmithing part will make sense.
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Alex,I don't think I could manage another 35years of it.
 
Alex Wheeler said:
Ok, I can see that point. I was only focusing on the guys posting which seem to all be doing this kind of work. To the ones reading, Id suggest getting off the gunsmithing forums and learn basic machine principals. Then the gunsmithing part will make sense.
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I only attempted cutting and chambering because I had a little bit of experience with lathes.
I’m FAR from an machinist though.

Shot the 6BRA that I did with my first pre bore today.
Pretty happy with results.
 
shortgrass said:
There are probably 100 guys reading these threads wanting to buy a lathe so they can 'chamber their own barrels'. 4-5 might end up setting a lathe in their garage or basement. Many don't know, so it's not "We all know its concentric to spindle rotation". Many come here to 'learn', I mostly come just for "kicks n giggles" and to see how many sacrificed the neighbors cat last week before they cut a chamber.
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My dog takes care of the neighborhood cats, but I try and keep the bore concentric to the lathe so my cuts are concentric to that :p
 
shortgrass said:
There are probably 100 guys reading these threads wanting to buy a lathe so they can 'chamber their own barrels'. 4-5 might end up setting a lathe in their garage or basement. Many don't know, so it's not "We all know its concentric to spindle rotation". Many come here to 'learn', I mostly come just for "kicks n giggles" and to see how many sacrificed the neighbors cat last week before they cut a chamber.
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Come on! Leave the pussey cats alone! It don't mean diddly how you cut the damn chamber. The only thing that matters is how it shoots. Lots of ways to do it. None of them are wrong if it shoots.
 
swd said:
All I know is after Jackie so graciously published his chambering method on the benchrestdotcom forum 15+ years ago my run out and chambering improved enough that other than experimenting a couple times, it’s the only way I’ve chambered since. Interapid should have sent Jackie a commission check for all the long reach indicators he’s sold for them.

I’ve seen it on this forum so many times where someone who thinks they know more than a gunsmith or shooter who is at the top of his respective sport and or trade denounce them to the point of they no longer share their knowledge. I can think of at least 4 world record holders and gunsmiths that rarely post now if at all.

There are certainly other ways to chamber but Jackie’s method is easy, fast and consistently gets extremely low run out. That is indisputable to me.
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Too bad the pictures he posted are no longer hosted by the site. Here is the link: http://benchrest.com/showthread.php?59097-Jackie-chambering-a-Barrel-(Pictures)
 
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I saved what I think is the original.

1..Indicating muzzle, chamber end is supported in headstock by alignment ring
1683555093701.png

2..Mitutoyo Indicator
1683555156379.png

3..Me and our Pratt & Whitney Tool Room Lathe.
1683555192100.png

4..Turning fit for tuner, .900 2 inches long.
1683555224863.png

5..Cutting Crown. Notice small end turned for alignment ring.
1683555264675.png

6..Cutting Crown.
1683555309956.png
 
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