Thursday, August 6, 2015

Now that was more like it.

Got back to the zeroing range today.  After last week's frustrating attempt with handloads, and without the time to find and remedy the problem at home, I ponied up for some good factory loads, and today was...much better.

I was a bit paranoid--after all, maybe it was just me:  you know, my shooting.  So I brought some of that good old M80 ball to shoot first, just so I could see if I could hit anything, and see where my sights might have been left over after last week.  So, at the 100 yard line, I shot my first three.

Click to embiggenate.

Well hell, that's a lot more satisfactory than anything I did a week ago.  The aim point was the diamond to the lower left, so the group is about 2.5" high and 2" right.  And importantly, it's a useful group, at a bit over an inch in dispersion.

Okay then, that's where the 147-grain load hits.  Lovely.  How about the Barnes VOR-TX 165-grain load?

First shot at bottom, next three above that, next three at top.

The first shot is the lowest one.  Works for me!  Now to raise the point of impact to about 2" to 2.5", to give me a good "maximum point-blank range" for a 6-inch target diameter.  (Both moose and caribou are much bigger than that, of course, but I figure this gives me a margin of error in my own shooting.)  I moved the reticle adjustment up a bit and shot three, and you can see the next three shots right above and to the right of the first one.  Nice tight group, but not quite as high as I wanted, so I went a bit further--and as you can see it was a bit too far.  Not only that, but the point of impact moved to the left at the same time!  (This is why you never adjust both planes at the same time.  :-)

And by this point I was feeling much better about my shooting.  A 2.5x scout scope is not exactly made for benchresting, and lots of people pooh-pooh it as being "underpowered", but as you can see it certainly can work!  But 3.5" is a bit too high.  Okay, back it down just a bit and shoot three (new target).

Good enough to hunt with!  1/2" right and just over 2" high.
This should give me just over 250 yards of MPBR and about 9" of drop at 300.

Now we're talking.  Back over to the right, okay, but more importantly just about the right height.  Using JBM Ballistics, and presuming about 2600f/s of muzzle velocity from the Scout's 19-inch barrel (I didn't chrony today), the two points of intersection with the line of sight should occur at exactly 25 yards and exactly 200 yards, with a MPBR of just over 250 and about a 9" drop at 300.  If for some reason I'm seeing the full 2700fps claimed on the box (which I'd not expect, but that Mannlicher barrel is known to shoot a bit faster than its short length would suggest), the numbers are little different:  0.1" down at 25 yards, 0.4" up at 200, MPBR of 265, and a drop of 8" at 300.  If for some reason I shoot well enough in the field to notice that, I'll...well, I won't, so no matter.

What's important to me is that I know that trajectory already, and I'm confident to 300 for hits with it. (Actually, I'm reasonably confident to 400 with a good steady rest, but I'm also of the opinion that you have to apologize for shooting that far away, and at any rate the problem out past 300 isn't so much setting the holdover properly, as it is being accurate about range estimation.  On a wounded animal getting away, sure, but I won't go that far for a first shot.

Okay, so I'm happy now, with zero.  I figured I'd finish with a quick test of position skills.  Using the M80 ball, which I know shoots a bit high and right relative to the Barnes, I shot one round from each position at a pistol target at 100.  The first three positions (squat, sitting, prone) used the Ching Sling, into which I looped up while acquiring the position;  the fourth was bipod prone;  and the fifth was an offhand shot, completely unsupported.  Each shot was acquired and delivered as fast as I could get a good position, sight picture and compressed surprise break--this was supposed to be "under pressure".    Of course, I snapped the bolt at each shot as well, and quitted each position reloaded and on-safe.

Yes, I'm happy with this as a quick test.  About 8" total dispersion, including offhand.

The aim point was the orange center on the pistol target;  I did not make any attempt to "Kentucky windage" any of these shots, even though I knew the ball load would print a bit higher and more to the right than the one I'm using "for blood"--which itself is zeroed about 2.25" high at this distance.  The offhand shot is over on the far right, at the edge of my "wobble zone", but it was within the zone, and delivered within about three seconds--yeah, I'm happy with it.

The supported shots, again taken as fast as I could manage them, show a dispersion of under 5", with an apparent center about 1.5" right and a little over 5" high.  If the ball load really does print about 2.5" higher and 2" to the right of the Barnes load, this would seem to suggest a group center of...about 2.5" high and within half an inch of right on for windage...  Yeah, I realize that's at least a bit of academic reasoning there, but still, if the purpose is to instill confidence, I'll take it.

Now...for the problem of finding the critter at the right time, and getting close enough for a good shot.  I think I can say now that if I get such a shot and blow it, it's on me, not on the rifle or the ammunition.

Good.  That's the way I like it.

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