Pre bore the chamber results?

[xr650rRider]

7.."Breaking Edge" with 600 grit emory paper. Run lathe forward, then reverse.


8..Finished Crown


9..Cutting thread for tuner. (.900, 36 tpi).


10..Checking Tuner fit.


11..Finished muzzle end.


12..Alignment ring installed.

 

[xr650rRider]

13..Barrel turned around, roughing out tenon fit.


14..Truing for initial rough drilling.


15..Ready to drill. Notice drill has 30 degree end ground.


16..Drilling Chamber


17..Chamber end rough drilled..


18..Indicator.

 

[xr650rRider]

19..Indicator inserted all the way in in order to dial in throat area.

20. Boring tool.

21..Boring Chamber end with compound set at correct taper.

22..Same as 21.

23..Final reaming, reamer only has about .003 metal to remove.

24..Reamer in all the way.

 

[xr650rRider]

25..Headspace gauge just past flush.

26..Final inspection with indicator.

27..Taking final cut on tenon..

28..Checking headspace.

29..Measuring headspace with depth mics.

30..finishing final headspace dimension by cutting shoulder.

 

[xr650rRider]

31..cutting cone.


32..Finished cone and shoulder.

33..Threading Tenon.

34..More Threading.

35. Using thread "triangles" to measure Pitch Diameter of thread.

 

[xr650rRider]

36..Finished tenon.


37..Polishing barrel OD with Scotch Brite.

38..Simpletools used for arriving at correct Headspace and Cone Dimensions.

..............jackie

 

[xr650rRider]

That write up was specifically for those that have a lathe with a headstock too long to use a spider, or for those that like to keep the muzzle running true at all times.

Gary Walters took the pictures, and posted them off of something like PhotoBucket.

I wish I had a way to retrieve them.

Best I could do.

 

[Carl S]

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.............

Interesting..what damage was the fixed piloted reamer doing..scratching the bore,cutting the throat-lead of centre?.i only use fixed piloted reamers that Mike supplies.the first time I used one I was concerned about bore damage but prebore seems to overcome that concern.everthing comes out good..consistently.thats why I stick with my method.i maybe lucky.if i can find a better way i will try it.it keeps that bad phone call away..the phone does ring alot but it isn't always to do with rifles or shotguns.it can be a structural welding job,engine or transmission rebuild.i never know.variety is the spice of life I was once told.

 

[shortgrass]

I am uncertain how pre-boring would make any difference, as the bored hole should come nowhere near where the pilot will be. As I said in my post, "where the pilot is at in the rifling", never mentioned the throat. The fixed pilot reamers left scratches in the bore, just ahead of the throat where the pilot had been. Throat was well centered, as that is where I had dialed-in to begin with. Now, I use no pilot at all, as the body of the reamer will follow the pre-bored 'hole'. That allows more oil to flow over the reamer at a lower pressure, also. A chucking reamer has no pilot, in a floating holder it just follows the drilled hole.

 

[boltfluter]

Best I could do.

Some very nice pics! Thanks for sharing and saving them. I am sure Jackie will be very happy.
Paul

 

[Carl S]

I am uncertain how pre-boring would make any difference, as the bored hole should come nowhere near where the pilot will be. As I said in my post, "where the pilot is at in the rifling", never mentioned the throat. The fixed pilot reamers left scratches in the bore, just ahead of the throat where the pilot had been. Throat was well centered, as that is where I had dialed-in to begin with. Now, I use no pilot at all, as the body of the reamer will follow the pre-bored 'hole'. That allows more oil to flow over the reamer at a lower pressure, also. A chucking reamer has no pilot, in a floating holder it just follows the drilled hole.

Yes i slightly missunderstood your question.i envision a solid piloted reamer possibly starting and cutting 'untrue' in the bore from start to finish without a true prebored hole for it to start in.as we no prebore keeps everything good.interests me how you was getting those scratches where the pilot finished in your finished chamber..maybe a piece of swarf somehow got there or slight curvature in the barrel at that point.im just thinking of possibilitys..did you ever find out what the cause was?the solid piloted reamers I've used are JGS..various small calibres up to big game calibres.i do everything the same and I don't have the flushing system running at high pressure really.like I've said I may be lucky.

 

[JFrank]

Man this thread went on for 24 days and 12 pages and I’m still not sure whether to pre bore or not.

Jim

 

[jackieschmidt]

I sure look young in those pictures.

We don’t even have that little Prat & Whitney lathe anymore.

 

[SKWERLZ]

Man this thread went on for 24 days and 12 pages and I’m still not sure whether to pre bore or not.

Jim

I’m still pre boring, especially long cartridge like RUM


Just seems faster.
It’s an option, I happen to like it, some don’t.

Accidentally dropped my carbide boring bar and it exploded, sooo mad about that.
Need to get another.

 

[LVLAaron]

Man this thread went on for 24 days and 12 pages and I’m still not sure whether to pre bore or not.

Jim

Yes. Especially if 5R

 

[swd]

I’ve been pre boring for at least 15 years. The only one I might not do would be something really tiny like a Hornet.