Latest Information
12/31/07 - .223AI F-Open 600
Yard Rifle
The
223AI has now morphed (again!) from a stock Savage 12FV in .223 Remington
into a F-Class Open starter rifle for my wife.
The Bell
and Carlson aftermarket stock was changed out for a MBR style
synthetic model from Sharp Shooters Supply two years ago.
At the
same time, I had also changed out the factory Accutrigger for a
SSS unit, as the factory trigger had gotten unreliable, and
would fail to cock, even when adjusted to over 1.5 pounds.
Apparently, this is not uncommon for the stock Savage
Accutriggers after a lot of use. The SSS trigger is set at 1
pound, and breaks cleanly, with no tendency to AD.
The
factory bolt handle was changed out to a stock Savage large
handle.
The
Pac-Nor pre-fit barrel installed in 2003 had finally given up
the ghost after the 2006 prairie dog hunt in South Dakota. There
had been over 4000 rounds fired through the barrel before
accuracy started to drop noticeably. So, in addition to the new
stock and trigger, the rifle was fitted with a new Brux
cut-rifled barrel. The barrel contour was a bit larger than the
stock factory Savage, being 0.930" vs. 0.750 at the muzzle.
This barrel was exceptionally straight in the bore, and the view
through the borescope looked excellent. I must also note that
dealing with Ken at Brux was extremely pleasant, and the
delivery time was a stunning two weeks after he received
payment. I'll be buying more barrels from them, you can be
assured of that.
The reamer was from Dave Kiff at PTG. (Drawings
HERE). It was ground to
provide the same throat dimension as the re-throated Pac-Nor,
which was optimized for the 75 grain Hornady AMax.
The
barrel channel on the SSS stock was enlarged on the mill with a
carbide 1.125" router bit, and skim bedded with black dyed
Marine-Tex epoxy. A length of 1.125" outside diameter 4140 thin wall tubing was
used as a form for this skim bedding. (An unused down-tube from
a Reynolds tube set left over from my street bike frame building
days).
A
Farrell 20 MOA Picatinny style base was bedded to the action
with Devcon 10110, and then pinned to the receiver with two
0.125" dowel pins to ensure that it never shifts.
Current
configuration for this rifle:
Caliber |
.223 Remington
Ackley Improved |
Barrel |
Brux
Stainless, 30 finished length, 4 groove, 1 : 8 twist,
1.050" for 2", then straight taper to 0.930" at the
muzzle |
Reamer |
Dave Kiff of
Pacific
Tool and Gauge .223AI, 0.250 neck, 0.105 freebore,
optimized for 75 AMax |
Receiver |
Savage 12FV, converted to single shot with shop made
follower |
Trigger |
Sharp
Shooters Supply Competition model |
Stock |
Sharp
Shooters Supply MBR style synthetic |
Scope rail |
Farrell 20MOA
Picatinny style, model SAV-RTS-1-20 |
Scope |
Burris Black
Diamond 8-32X50, 30mm tube |
Rings |
Leupold QRW high, 30MM |
Weight |
19.5
pounds |
Break-in at the range today went
exceptionally well. There was zero, and I mean zero, copper
fouling, even on the first few shots. The shoot one, clean one
routine was not necessary. This is the fastest break-in I have
ever experienced. A solid testimony to the quality of the Brux
barrel.
The ammo used was the standard accuracy
load for the old Pac-Nor barrel: 25.5 grain VVN140, 75 AMax, WSR
primer, 223AI fireformed cases from LC brass. Five shot groups
were all under 0.5" at 100 yards. A total of thirty rounds were
fired.
Next steps are to do some
load development. The goal is to repeat the 5 shot grouping in
the 3's of the original Pac-Nor barrel, and achieve a low
velocity SD so that the load will be a good performer at 300 to
600 yard F-Class competitions.
Archival Information
Original
Postings
August
2003
.223 Remington
Ackley Improved Re-barreling Project
This fall I
purchased a 27 stainless steel super-match grade barrel, 1:8
twist from Pac-Nor. My intent was to be able to shoot the heavy
(75 and 80 grain) VLD bullets very accurately, at reasonable
velocities. The standard .223 Remington cannot really drive the
heavy bullets more than about 2700 FPS without high pressures. I
wanted a load that would drive a 75 grain AMAX or an 80 grain
Berger VLD at about 2900-3000 FPS, at sub-MOA accuracies.
Chris and Penny at
Pac-Nor really took good care of me, and did a great job with
the barrel, which was chambered and pre-fit for the Savage
action very nicely. It took only a Savage barrel nut wrench, a
barrel vice (two chunks of 2X4 cross drilled with a 1 hole),
two go/no go gauges, and about 10 minutes to remove the factory
barrel and mount the Pac-Nor barrel.
Here are some
pictures taken through my Hawkeye borescope with a digital
camera. They really show off the exceptional quality of the bore
and the throat on this barrel. I liked this barrel so much, I
ordered another SSSM from Pac-Nor for fitting to my 220 Swift by
a local smith.
This is a shot of the
bore of the brand new Pac-Nor SSSM .223 Remington Ackley Improved. This picture
was taken with a Kodak DC290 digital camera through a Hawkeye borescope:
This is the throat of the same barrel.
Note the absence of any significant tooling marks. This barrel shoots very, very
well:
This barrel lived
up to my expectations. The performance with the VLDs was
consistently one third MOA or less, with 0.6 5 shot groups at
200 yards the norm. However, the throat length was a bit too
short, and the VLDs were set into the case a bit too far,
limiting the amount of powder volume that was available. I
decided to send the barrel back to Pac-Nor and have them extend
the throat out by about 0.100.
Here is a picture
of the Savage with Pac-Nor barrel installed and the Weaver T36
scope:
UPDATE:
10/18/03
I just had the
throat lengthened at Pac-Nor by about 0.100 in order to be able
to seat the heavy 75 and 80 grain VLD bullets properly. The
original throating from Pac-Nor was for the lighter bullets, and
the VLDs were seating too far into the case, reducing the volume
available for powder. I had to increase the powder charge
(VVN140 and IMR4895) by 1.0 grain to get the barrel time and
velocity back to the original accuracy load levels. The rifle
shoots even better than before. Here is a typical 5 shot group
from todays session, at 100 yards. I will post the 200 yard
data as it becomes available.
Re-throated Pac-Nor SSSM 27 .223 Ackley Improved, 1:8 twist,
COL 2.525
75
grain Hornady Amax, 25.5 grains VVN140, CCI BR4 primer, Lake
City brass, fire formed
5
shot group @ 100 yards, 0.28
Average 2948 FPS, extreme spread 60 FPS, standard deviation 25
FPS
UPDATE:
10/27/03
The performance at
200 yards with the Hornady AMax was very, very good, and I doubt
that it can be much better. The rifle clearly is limited only by
the performance of the loose nut squeezing the trigger. With an
extreme spread of only 51 FPS (30 shot aggregate), the expected
vertical error is less than 3 at 500 yards. This should make
for a very nice prairie dog rifle out to 500+ yards.
Re-throated Pac-Nor SSSM 27
.223 Ackley Improved, 1:8 twist, COL 2.525
75 grain Hornady Amax, 25.5 grains VVN140, CCI BR4 primer,
Lake City brass, fire formed
5 shot group @ 200 yards, 0.476
Average 2938 FPS, extreme spread 51 FPS, standard
deviation 12 FPS
Load and performance information on my .223 Remington Ackley
Improved project rifle Includes some
optimum barrel time estimates and a list of the best shooting
loads to date. Note that there are two pages of data, one for
the barrel as originally received from Pac-Nor, and one after
the throat was extended about 0.100 |