From: [g--ff--n] at [primenet.com] (geoff beneze)
Newsgroups: rec.guns
Subject: Project Gun - Fire Lapping
Date: 2 Sep 1996 08:39:32 -0400

Well, here are some results. If you'll remember, I'm starting out with a
box stock Ruger M77 MkII V/T in 308 with the Tasco World Class Target
model 6x24. At this point I've done virtually NO load development. The
load I'm using is 41 gr. Win 748 with a Sierra 168 HPBT Match King set
.005" off the lands. This is going to be my test bed, and I'll include
Cryo treatment of the barrel, bedding and any other goodies I can think of
that don't cost more than the gun. 

As some of you will recall, the first step in this game was going to be
fire lapping the barrel. Ron and I both did this over the holiday weekend
to our respective 308's. I'm using the kit from NECO and fired a sequence
of 10 - 220 grit, 12- 400 grit, 15 - 800 grit and 30 - 1200 grit. We
cleaned barrels at REGULAR, but logical intervals throughout the process,
(e.g. five shots for 220, six shots for 400, five shots for 800, and six
shots for 1200.)

 I've used two different measuring systems, one by hand, outer edge to
outer edge minus bullet diameter. THEN I used Recreational Software's "Gun
Control." With this software, you hold the target to the screen, then
click through the bullet holes. The program calculates all kinds of
interesting stuff. 

While my measurements are somewhat smaller than those calculated by GC
(oddly enough) the ratio of the difference is the same for either method
(that is, the difference between the two sets of groups using my method
and their is the same.)

Soooo, on the theory that the computer can't lie as well as I can, I'll
use the figures from GC. In these figures, I've included EVERY group
fired, including those that I KNEW I'd thrown a flyer, and those that
looked perfect and sent one off into the boonies. Also a factor in these
numbers is the fact that in the valley where I have my range, the wind
ALWAYS blows at 90 degrees to the direction of fire. In short, I've done
everything in MY power to have the numbers be absolutely REAL without my
imagination or desire effecting the outcome. 

Ok, ready for numbers?

Before the fire lapping started, on three different days, I fired a total
of 15 THREE shot groups. The GC average for these groups (flyers and all)
was 1.04" (sorry, I'm NOT going to get down to three our four places.)

After lapping (finished this morning), I've fired 10 THREE shot groups.
The GC average for these groups is (drum roll) .82"

I'm smiling, and cleaning the gun is amazing, the patch goes through the
barrel with almost NO resistance and comes clean in 1/2 the "normal" time.


Further testimonial for lapping. I lapped the barrel on a 1911 single
stack I'm building. When new, this barrel was a lead mine, now it looks
like a mirror and I get the slightest amount of leading right in front of
the chamber. Normally I'll soak the barrel in MP-7 for a couple of hours,
then brush the snot out of it and it's clean - WONDERFUL.

In a nutshell, fire lapping has ME convinced from a couple of different
directions. All my accuracy guns will now get this treatment. The next
stop for the Ruger is probably going to be glass bedding, then Cryo
treatment.
-- 
From: [g--ff--n] at [primenet.com] (geoff beneze)
Newsgroups: rec.guns
Subject: Re: Project Gun - Fire Lapping
Date: 3 Sep 1996 00:59:01 -0400

In article <50eki4$[b c n] at [xring.cs.umd.edu]>, [g--ff--n] at [primenet.com] (geoff
beneze) wrote:

# Well, here are some results. If you'll remember, I'm starting out with a
# box stock Ruger M77 MkII V/T in 308 with the Tasco World Class Target
# model 6x24. At this point I've done virtually NO load development. The
# load I'm using is 41 gr. Win 748 with a Sierra 168 HPBT Match King set
# .005" off the lands. This is going to be my test bed, and I'll include
# Cryo treatment of the barrel, bedding and any other goodies I can think of
# that don't cost more than the gun. 

One bit of data I didn't have when I posted this. As per predictions for
the fire lapping process, I have "realized" a drop in velocity. The before
velocity was 2665 and the after was 2585, a drop of approximately 85 fps. 

Stay tuned for the next episode, glass bedding and results (around the
first weekend of October)
-- 
geoff beneze
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