On Mon, 12 Apr 2010 13:01:36 -0700, Gunner Asch
wrote:

On Mon, 12 Apr 2010 01:02:31 -0500, Don Foreman
wrote:

On Sun, 11 Apr 2010 13:55:28 -0700, Gunner Asch
wrote:


Separate pillar posts epoxied into the stock.


How did you level them?

Gunner

I spaced the action from the stock using several thicknesses of 10-mil
PVC pipe tape wrapped around the barrel and applied under the tang.
Nobody in MN ever heard of this tape but I guess it's common in CA and
I found it online. Shipping cost more than the roll of tape, about 10
bux total.

I applied several thicknesses of tape to tang and barrel until the
action and barrel were level with the stock but everywhere clear of it
by at least 12 mils as tested with 4 thicknesses of paper sliding
underneath. Also made sure that the action was a teense above center
to avoid getting it locked in by epoxy. I did some milling and
sanding of the stock to get there. A very useful tool was a 3/4" dia
ball end mill from Grizzly, about 20 bux.

I then jacked the pillars into place using studs made for that
purpose. The holes in the pillars are N-drill dia (.302" I think)
while the mounting bolts are 1/4-28, so the bolts will not touch the
interior walls of the pillars in service. The studs are .301" dia
aside from where they're threaded 1/4-28. Single-use studs, made to
fit this rifle and stock. Only took a few enjoyable minutes to make
them at the lathe.

The idea is to have the primary points of contact between stock and
action be the pillars, with the action in intimate contact with stock
(and bedding) while the barrel touches nothing. The objective is to
approach zero variability from shot to shot. Doesn't much matter where
the rifle shoots relative to boresight, what matters is how
consistently it can do it for a few rounds after a fouling round and
perhaps a sighting round.

The rear pillar ended up just slightly proud of the stock, maybe 10
thou, down in the trigger guard pocket underneath the stock because
that bolt also engages the trigger guard. This fit wasn't an accident
but a result of some careful measurements with an Etalon dial caliper.
Digital calipers are wonderful but the Etalon is my goto when I want
the best a caliper can do.

The Savage package rifles use a plastic trigger guard but I'm
replacing that with a metal one from I forget where but could find it
if you want to know. It was 20 bux.

The goo is in as of tonight. It's curing as I type. I didn't get
nearly as much squeeze-out as I expected, though I thought I had
plenty of goo in there. I made up 100 grams of goo after figuring that
50 grams should suffice. Now I'm thinking I should have filled the
blind magazine pocket with a styrofoam plug. Conventional practice is
to fill it with modelling clay, but I figured that epoxy would be a
lot easier to clean out of there than modelling clay if one has a
vertical mill and I do. I still think that, but maybe I need to block
that venue for hydraulic squeeze better than I did this time. The
ideal is to have the goo squish out and need about 100 cue-tips to
clean off the stock which has been protected by green masking tape
from the autobody supply store. Butch's Bore-Shine, being
ammonia-based, is a very effective solvent for final cleanup of
expressed epoxy goo and only costs about 100x a similar qty of
household ammonia. It was conveniently at hand and got 'er done.

This is a first-time learning exercise. This rifle was selected for
that with the notion that pillar-bedding it (however ineptly) can't
hurt, probably will help and I'm bound to learn by doing. The rifle I
really want to get right is a Savage BVSS .22-250.

I am not gonna touch my little CZ527 American in .223. It already
shoots 0.5 MOA off the bench with loads it likes, though it's a
lightweight sporter rather than a bench or varmint rifle. Great fun
to shoot from kneeling, sitting or with bipod, can do headshots on
whistlepigs inside of 200 meters and punch Necco wafers at the range
for fun. It's a fun little rifle, has fetched a big grin from
everyone who's tried it. I'm very glad I bought it when I did.


Sounds like you got it all proper and everything! Way to go!

And they say one cant teach an old dog new tricks...pshaw!

Nice job Don, and good explaination.

Gunner

Not so blinkin' fast, hombre! My next one may turn out to be a nice
job, but I won't be posting any photos of this one! G

This rifle has an internal magazine rather than using a detachable box
magazine. The DVD said to pack the hole with modelling clay. Well,
that's a buncha clay and I can imagine what a joy it would be to clean
out of there, so I figured the goo could just leak in there a little
and I could remove it with the mill.

Problem was, because it had somewhere to go down it didn't
hydraulically squish up and out in that region. Made cleanup much
easier, only used about 20 cue-tips, but I didn't get good bedding in
the region alongide the mag cavity. I don't think that will matter
because it'd only be a couple of thin strips on rather thin wood --
but it does look pretty amateurish. Well, hell, I *am* an amateur. It
won't show at all when the rifle is assembled. On the next one I will
fill that magazine cavity with something.

I got nice-looking void-free bedding under the action away from the
magazine cavity, near and around both pillars and around the recoil
lug. I think that should suffice for shooting purposes which is the
reason for doing it in the first place. If it doesn't shoot better
than before I can always go back and add more goo to get the missed
regions -- but I really doubt that it'd make any difference in
performance. I think the main thing is to have the rifle solidly
mounted and bedded around the pillars, good fore-and-aft capture of
the recoil lug, with the stock not touching the barrelled action
anywhere else.

I was pleased and a bit relieved to see how easily the barrelled
action separated from the epoxied stock. I did use release agent
thoroughly and liberally. Couple of smart whacks with a deadblow soft
hammer on the mounting studs was all it took to pop it loose.

Might be a few days before I get to the range to see how it works.