From: bartb@hpfcla.fc.hp.com (Bart Bobbitt)
Subject: Re: Barrel Fitting -- A FAQ Question?
Organization: Hewlett-Packard Fort Collins Site

K. Karcich (kkrh@troi.cc.rochester.edu) wrote:

: #  * button rifled, they'll get bigger.

: If the barrel is well stress relieved, and they are gently turned, then no
: measurable change can result. However, many of the cheaper barrels are not
: properly stress relieved, and nasty changes can occur.

I'd agree, except several folks have tried to peel tiny slivers off of
Hart, Schneider, Shilen and other button-rifled barrels.  They all shot
worse (less accuracy) than before.  Measuring their bore/groove showed
increased dimensions, although only a few ten-thousandths of an inch.

BB

From: bartb@hpfcla.fc.hp.com (Bart Bobbitt)
Subject: Re: Barrel Fitting -- A FAQ Question?
Organization: Hewlett-Packard Fort Collins Site

K. Karcich (kkrh@troi.cc.rochester.edu) wrote:

: Shilens cost as much as Krieger or Obermeyer, actually more.

Shilen can sell his barrels for as much as he wants to.

: #The best barrels are profiled before rifling; both cut and button types.

: This is not my understanding of the button process.

Although some may be profiled after rifling, the lapping to uniform
bore/groove dimensions is done after profiling.  I didn't make that point
clear at first.

: McMillan barrels are commonly fluted as a custom,
: on demand extra. Does fluting
: not cause dimensional changes?

Yes.  That's why Obermeyer laps his fluted barrels to finish dimension
after milling the flutes in them.  Fluting barrel does the same thing as
turning one down.  Cut rifled barrels change more in bore/groove dimension
when fluted than when turned down in diameter.  As flutes need to be as
deep as possible to be worthwhile, that much milling definitely changes
the stress situation in barrels.

: Read the ...  question again. If a barrel has already been profiled, and
: previously rifled, its groove diameter is X. If you do minor turning on that
: barrel, and its properly stress relieved, its my contention that it will be
: very difficult to detect minor changes even by air gauging and its groove
: diameter will remain X.

Minor turning, like a few thousandths won't change a cut rifled barrel.
But it will change a button rifled barrel.  Which is one reason why
Obermeyer, and Jack Krieger, cut rifle their barrels.  I think I've made
the distinction between cut and buttoned barrels before........

: Shilens are pretty accurate.

And short-lived, too.  I've known some highpower shooters who used 'em in
.308 Win. and didn't even get 1000 rounds out of 'em before they opened
up a minute or so.  They even last fewer rounds than Schneider barrel.

BB