| By: Larry Weeks
Last month we did some
shooting, bedded the action
into the stock and did some more shooting. This month, we’ll
start out
with a trigger adjustment, shoot a bit more, then explain
what we’re going
to do next and introduce the Dave Manson tooling we’ll use
to fully accurize
the action.
We talked a bit about group shooting techniques and I ran
across an article
that’s well worth a read if you want to get the best groups
out of your
gun. Written by Craig Boddington, it ran in the March/April,
2004 issue
of Petersen’s RifleShooter magazine. The issue is
going with
me to the
range next time I shoot the project 700. If you can’t find the
issue,
try calling 800-260-6397 to purchase a copy.
Trigger Adjustment and Some Range Time
We knew all along the heavy, 6-1/2 pound trigger had to be
fixed but also knew it wouldn’t be fair to shoot some groups with
the heavy pull and some with the light pull; until we reached a
reasonable changeover point.
The Remington factory trigger can be adjusted for sear
engagement, spring pressure (pull weight) and overtravel. But not
by ME! This is one job you should leave to a competent gunsmith.
My partner in crime on this project, Marc D’Aguanno, definitely
qualifies and took the trigger down to a nice, 2-1/2 lb reading on
the Chatillon trigger pull gauge. He eliminated the creep and the
overtravel in the process.
If you don’t have a good trigger pull gauge, Brownells carries
a few.
Be sure to take a look at the Electronic
Pull Gauge from Lyman or Premium
Trigger Pull Gauge from RCBS.
This was our chance to try some handloads and some more
of our Cloverleaf ammo to see what the trigger work did. Marc’s
first 5 rounds of 95 grain, Berger bullets over 44.5 grains of
IMR4831 lit by Remington 9-1/2 primers - a load that had worked
well for him in other .243s - scattered like an open choked
shotgun. Completely unpredictable and roughly 12” across! We
immediately headed back to the shop where he totally
disassembled the rifle to see if something was broken.
Everything checked out okay, which left Marc suspicious of
the scope. We borrowed yet another one from his collection and
made the 3-mile drive back to the range. This Sunday afternoon
wasn’t at all like the calm conditions we had been shooting in
before. The wind was swirling out of the shallow valley to our
south, bouncing up, over the road and its ditches, about 50 yards
behind the shooting line, varying from the south all the way
around to east southeast.
Since everything seemed to have gone wrong, we went back
to something we knew, the 100 grain Cloveleaf loads. With the
gusting wind, Marc shot a quick group just to see if we could get
some sort of group. It came out just under 2” with no attempt to
match wind conditions between shots or let the barrel cool. In
went the Bergers. The first two shots were once again almost a
foot apart showing that this barrel absolutely hated this
powder/bullet combination as much as it hated the factory loads
we’d tried earlier.
He suggested I try the Cloverleaf 80 grains. I actually had the
presence of mind to consider the wind strength when I squeezed
the trigger for my first shot. Man, what a difference! That lighter,
cleaner trigger made it so nice for an amateur like me. The shot
landed just an inch or so from the aiming point, perfect for our
purposes. I was so thrilled that I rushed the second shot, thinking
I was invincible, but the wind gust that hit as I pulled the trigger
reminded me; and blew the shot an inch and a half or so to the
left. I knew it the second I fired and told Marc it was going to be
out the group before we even looked through the spotting scope.
Being humbled, I was a lot more careful for number three.
We’d been noticing that shots number three and four were usually
the ones that expanded the group. I was very careful to try and
get the same wind feel on my face as I had for shot one before I
pulled the trigger. Waiting with the crosshairs lined up is absolute
murder. But, with the nice trigger, I was able to think “shoot”
when the wind felt right and bang, the gun responded. Shot
number three landed just 1/2” away from the first one! Yee ha! I
actually felt like I was learning something. I just about had the
crosshairs lined up again when the wind dropped sooner than I
expected. I finished the lineup and quickly squeezed off number
four. It landed right next to number one. Now the pressure was
on.
Having fired two rounds so close together, I worried about
the temperature of our thin barrel. So, I sat away from the gun
and let it cool for about two minutes. Of course Marc was “helping”
by telling me how much the last shot counted. Having friends is so
nice, isn’t it? The sight picture came in instantly, the wind dropped
as if on cue and shot number five dropped in beside shot three
giving us a four round 1/2” cluster, with that called flyer making
the total 1-9/16”. With the wind whipping around like it was,
neither one of us wanted go through the tension of shooting a
backup group. By this time, we’d shot the gun, and the 80 grain
load enough, we were confident that our gun would be capable of
sub-one-inch, five-shot groups with the right loads.
What’d we learn? A good trigger makes all the difference in
the world. Lightening the pull cut the group size basically in half.
Of course we have to do a disclaimer here, you know, you’re
results may vary, etc., etc. And, "gun-friendly" ammo does make a
big difference.
Four shots in 1/2” with a called flyer for
1-9/16”
Accurizing
The next step is a complete accurizing job on the action. That
word gets
used so much, it’s darn near become like
Kleenex®.
You know, anything you blow your nose on is called
Kleenex®,
even though it’s really generic “Facial
Tissue.” At
least that’s what the folks from Kimberly-Clark have
to say.
Accurizing is like that.
Anytime anyone does something to make a gun shoot better
they call it “accurizing.” I guess what we’re going to do, actually
Marc will do, should really be called “blueprinting.” It’s a term I first
heard as a gear-head, car nut kid, you know, “. . . the engine is
balanced and blueprinted.”
We’ll use tooling made by Dave Manson Precision Reamers to
square and true things up to make sure the action, bolt, and
barrel are all in a straight line. Not knocking Remington, but
drawings have tolerances and mass production tooling wears a bit
every time you use it. Tolerances mean dimensions can be “off” a
whisker and still pass inspection.
Putting everything in a line should help accuracy. How? If
everything is dead straight when the cartridge goes “bang,” the
recoil force should make the bolt, recoil lug, action, etc. move
exactly the same, time after time. Think about it, if the face of the
action isn’t square against the shank of the barrel, or the bolt
doesn’t contact the lugs inside the action squarely, the slight gap
on one side – so small you can’t even see it – would act sort of like
hitting a nail on one side of the head. You know what happens
when you do that, the nail either goes in crooked, or bends. If
anything bends in our group of parts, the bullet could end up on a
crooked path. Think of the cartridge as the hammer, the bolt and
action are the nail.
Dave’s whole tool set will cost $500 to $600 for the
Receiver
Accurizing System and the Receiver
Ring Facing Tool. A bit much for someone doing only one
receiver.
But, it doesn’t require a lathe, and can be done by
the home gunsmith.
So, if you can get several jobs out of the tooling for
Remington 700s or Winchester Model 70 Classics, it will work
out.
Since we want to use the barrel we’ve had all along
to make sure
our test is valid, we picked the “Standard”
Tooling. There’s
also a .101”
Over Receiver Accurizing System that requires a barrel
threaded, and
on a lathe, to match the oversize dimension. That takes the
project out
of the home gunsmith category.
The Manson Receiver Accurizing System
Okay, after all that, let’s talk about
the tooling
itself. First of all, it’s all guided by bushings that fit inside the
action, where the bolt rides – guess you could call it the bolt
tunnel
or raceway.
The first piece is the Piloted Receiver Reamer. It does two
jobs, cuts the minor diameter of the threads and squares up the
bolt lug recesses inside the action. On the Standard diameter Kit,
you don’t really expect the cutter to do much to the inside
diameter of the barrel thread area in the action, but it may take
out a little bit. The big thing the Standard diameter reamer does is
square up the surfaces the bolt’s lugs ride against in the action.
That’s a big part of the straight-back push thing we’re talking
about.
Next is the Piloted Tap/Mandrel. It actually re-cuts the threads,
and since it’s piloted off the same bushings as the Receiver
Reamer, those threads will be dead-on straight.
For the receiver face, there’s the Receiver
Ring Facing Cutter. It doesn’t come in the kit, so you’ll
need to
order it separately. Three carbide blades cut the very front
face of the
receiver. Since it also pilots off the same bushings as the first
two
tools, once again, things will be absolutely straight.
That covers the introduction to the Manson tools, next time
we’ll put
them to work and see how much better my new Remington
700 can shoot!
|