Roughing Reamer

[alinwa]

And people in the bore of MRI have been killed by oxygen tanks that went in and struck them.

A few have been killed by being struck in the head my objects pulled into the bore.
Others have just been injured.

Smaller objects not aligned with teh bore will just stop on the housing.

Of course if your head was centered up ant that staple went down the bore it might be a little hard on your face or eye.

Whew, that part about getting mugged by an O2 tank definately gives one cause for pause eh.....my tank is AL for saves weight so's I should be OK...or maybe just get injured.....or maybe it'll fall really slow cuz eddy currents, cool! (I'ma' go pitch my tank down the hole, see what happens! If youtube is right I might have invented an aluminium parachute!)


I keep my head perty centered up though after The Incident.... I first used this thing laying down, skidded in Injun Style on my butt (mine came with a busted loading ramp so's I gutted 'er out to a bigger bore)....my plan was to work the clips on my lap but WHEWWW!!! The steel pins holding my pelvic girdle together just WHAMMED my butt down and when I strained upwards the steel plate in my head attached itself to the other wall! So's I'm humping my way out (pain!!) and The Wife comes by, she's all "whaddaya' DOIN' with that thing?? You look like you got worms....."

 

[lngrng]

As per usual Al, your sense of humor just slays me!

 

[JerrySharrett]

I have been fitting barrels to 6mm PPC rifles and decided to get new reamers, a resize, roughing and finishing reamer, this time I used a roughing reamer for the first time to save the finishing reamer wear.
The finishing reamer seemed to line up correctly after using the roughing reamer and seemed to run true to the barrel, BUT the accuracy of the barrels dropped off badly using a roughing reamer, then I did another barrel with out the roughing reamer and the accuracy came back, then rechambered one of the first barrels I used a roughing reamer in with out the roughing reamer and that accuracy came back, I am using a floating reamer holder both times.
Some people do not use a roughing reamer for accuracy at all, this is the question I would like help with, what happened ?, 3 barrels using roughing reamer lucky to get .3s, no roughing reamer .1s, is it the floating reamer tool causing this, I will not be using the roughing reamer again, can some one tell me what went wrong with out just saying we don't use them, have you had trouble with this before on barrels, I would rather wear out a finishing reamer than have this again, thankyou for the help.
Mark

Did you look at the leade ramps at the end of the freebore? They should all be the same length. If they are uneaven (some longer than others) that barrel will not shoot accurately.

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[Mark t]

Roughing reamer problems

Jerry

Thanks for answering Jerry, when I finish a chamber I look over it with a bore scope before it comes out of the lathe, at the free bore for the reason you suggested, marks on the neck and body etc, everything seems perfect??? but there is a problem some where.
The resizing die changed to a tighter one also after using the finishing reamer only, the barrels using my old reamer used the larger sizing die and shot like stink, just something weird happening, any more input would be great.
Mark

 

[JerrySharrett]

Jerry

Thanks for answering Jerry, when I finish a chamber I look over it with a bore scope before it comes out of the lathe, at the free bore for the reason you suggested, marks on the neck and body etc, everything seems perfect??? but there is a problem some where.
The resizing die changed to a tighter one also after using the finishing reamer only, the barrels using my old reamer used the larger sizing die and shot like stink, just something weird happening, any more input would be great.
Mark

Mark, were you using two different finish reamers when you got the two different results? Benchrest reamers only have about 0.004" difference between GO and NoGO where regular reamers have about 0.010" diff.

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[Mark t]

Roughing reamer

Jerry

I used the same finishing reamer on both chambers, seating depths are the same to the go gauge exactly the same not +or- to 0.0005 they were zero exactly the same.
I am wondering about the floating reamer holder causing the problem from roughing reamer to guiding the finishing reamer??
Some people say they should not use a roughing reamer and I am wondering why, thanks for your input Jerry.

Mark

 

[JerrySharrett]

Jerry

I used the same finishing reamer on both chambers, seating depths are the same to the go gauge exactly the same not +or- to 0.0005 they were zero exactly the same.
I am wondering about the floating reamer holder causing the problem from roughing reamer to guiding the finishing reamer??
Some people say they should not use a roughing reamer and I am wondering why, thanks for your input Jerry.

Mark

On One of the two chambers you should be able to feel some sideways movement with the bare reamer, with the pilot bushing removed, when the reamer is fully inserted. That chamber is the one in error.

Being 0.002-0.005" oversized can effect the sizing die required but should not effect the accuracy.....unless your finish reamer is not cleaning up where the rougher cut. I.e. Your rougher may be cutting oversized.

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