February 2012 Issue - Target Shooter Magazine

Sorting a Savage Part 2
THE CONCLUSION By Laurie Holland
groups mind you but the four batches covering 24.9
to 25.2gn ran at 0.15” to 0.4” (figure 3). Wow! Cracked
it (again!). All I needed was a long-range match in
reasonable conditions to prove I was back in business.
...and Dashed!
The PSSA competition calendar fixtures allied to long
bouts of stormy weather denied me that opportunity
until the second Saturday of the new year, which saw a
600 yard F-Class match coincide with cold but settled
weather – only 600 yards but enough distance to show
if the ‘verticals’ had gone.
New load or not they hadn’t, or at least not in the
first half of the event. If anything, things were worse
with the corrected elevation graph jumping up and
down the paper between shots to produce a 2.5-MOA
overall spread and more often than not a ‘minute’ of
movement between shots. Then at shot 13 everything
appeared to settle down and things were much
improved to shot 19 - five of the seven hits displaying
really impressive consistency. A glimmer of hope
appeared – if my final shot stayed within a quarter
minute variation, things were maybe on the up. Sadly
not – along with my hopes, the strike went way, way
down again, now at the very bottom of the four-ring,
a drop of around 0.8-MOA on the PSSA 500/600yd ‘F’
target.
So, what is going on? I wish I knew! I feel I’m just on
the edge of getting it back together again. Maybe
checking and re-tuning the cartridge overall lengths,
looking at neck tension, retrying some of the powders
originally rejected, switching from the 90gn VLD
to the 80.5gn and 90gn Berger BT designs will get
it shooting well again. However, national GBFCA
League rounds are approaching fast and getting loads
sorted for my newly rebarrelled .308 Win F/TR rifle
looks a lot less risky at the minute!
Lots of people did warn me when I started out with
long-range .223 Rem that the cartridge is incredibly
finicky with 90gn bullets and often just goes ‘out of
tune’ for no apparent reason. I think the lesson for me
as well as others is just how ‘high-maintenance’ this
combination is. If everything isn’t perfect, it simply
doesn’t work.
Figure 1: rear screw tension set at 5 – 20 in/lb
Figure 2: rear screw tensions above 20 in/lb
made groups considerably larger
18 19
I did say before that I’d pass a little more load data on.
Late last year after a new barrel went on, I decided to
give Viht N150 a try. I’d avoided the powder previously
after hearing from Jerry Tierney over in California
that he’d had some worrying pressure spikes with it,
Figure 3: With the tension at just under 15 in/lb, a return to the 90gn VLD / Re15
ammunition combination appeared to have got the rifle shooting well again
getting a huge rise in MV and pressure signs from a
0.2gn charge weight increase. I’ve always liked this
powder with heavy bullets in the cartridge and decided
to give it a try, albeit acting very warily.
Five batches in well-used Lapua match brass, CCI-450
SR Magnum primer and charges of N150 rising from
23.6 to 24.0gn in 0.1gn steps (weighed on Acculab
high-quality electronic scales to accurately allow such
small differentiations) produced 0.2 to 0.7” groups,
only one exceeding the half-inch. The top load
produced a modest MV of 2,641 fps with a small ES of
9 fps, so there is scope for working it up a bit higher.
Before shooters scoff at such ‘low performance’, run
the 90gn Berger BTLR’s external ballistics on a decent
G7 based program. The 800 yard wind-drift for a 2,640
fps load is 6.7-MOA in the classic 10 mph 90-degree
crosswind which is better than that of the NRA’s RWS
.308W / 155gn SMK ammunition, assuming that the
latter produces a full 3,000 fps MV from a ‘tight-bore’
30 inch barrel.
Retained velocities and wind-drift values for this load
fall between those of the ‘old’ and ‘new’ 155gn Sierra
‘Palma’ MKs at a full 3,000 fps MV in fact. I wouldn’t
Sorting a Savage Part 2
THE CONCLUSION
By Laurie Holland
tout this as a 1000 yard load but it shows a great deal
of promise for the shorter-range club shooter, has no
recoil to speak of and will probably give 4,000-5,000
rounds barrel accuracy
life. The 80.5gn Berger
BT at 2800-2900 fps is
gaining a good reputation
too and I’ll try this bullet
later on in the year in
my F/TR rifle as well as
another Savage .223 we’re
working on – a rebarrelled
‘sporter’ designated as ‘an
affordable clubman’s F/TR
rifle’.
Figure 4: Graphed
elevations of the 20 shots in the 600yd Diggle F Class
competition corrected to a common elevation setting
on the riflescope. Despite the use of the Re15 load,
the problem has not been solved! 0 = perfect elevation
with a strike on the V-Bull centreline; low shots have
minus values; high shots have plus values. Shots 13-
19 suggest a solution may be close