Newsgroups: rec.crafts.metalworking,rec.guns
Subject: Re: Liquid nitrogen gun barrel dip?
Message-ID: <1994Dec6.011140.29121@bbxrbk.basis.com>
From: bbxrbk!russ@basis.com (Russ Kepler)
Date: 5 Dec 1994 22:24:36 -0500
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In article <199412040049.AA00100@eskimo.com>,
W. Sugai <wsugai@eskimo.com> wrote:
#In article <3bqlrg$3ii0@whale.st.usm.edu>,
#Donald R. Newcomb <dnewcomb@whale.st.usm.edu> wrote:
##Can someone give me a simple explanation of why chilling a barrel
##in liquid nitrogen would make it shoot better? Thanks.

Cryogenic cooling can help in stabilizing metals, and is used in very
high precision work (usually at the gage level, about .000001 in 1"
level).  I'm not aware that a barrel is critical in this dimension, and
know that consistency in the barrel exceeding .0001" through the 
entire bore is considered pretty good (the best barrels are lapped
to better than that).

So, I'd work on a lot of other things on a rifle before I went to the
bother of doing a cryogenic treat on the barrel (heck, most problems
are bedding, trigger or shooter anyway, even with the real precision
shooters).  I'm not sure that there is a shooter in the US that would
be able to see the difference (against the noise induced by wind,
powder variation, bullet variation, temperature, barrel temp, feeding
irregularities, primer differences, primer seating differences, case
differences, bolt set changes, action shifts, etc.)

-- 
Russ Kepler posting from home  russ@bbxrbk.basis.com

                      Please don't feed the Engineers