Re: long range accuracy

07 December 2004, 13:50

Well try this..
Get out somewhere where you can actually shoot at a 500 yard target, verified by rangefinder. Shoot some groups, allowing your barrel to cool between groups of course.
Then immediatly take that same load and shoot some groups at 100 yards. Put the groups you shot at 500 yards along side the groups you shot at 100 yards.
Take some digital pics and post 'em here.
We'll take it from there..

07 December 2004, 14:11

djpaintles

Theoretically a rifle that will shoot 1" groups at 100yds should be able to shoot 5" groups at 500yds. In practice it just isn't so. The longer the range gets the more mirage, wind and other effects come into play. I've seen a whole lot more rifles that will shoot 1/2" at 100yds than will shoot 1 1/2" groups at 300yds much less 2 1/2" groups at 500yds.........DJ

07 December 2004, 17:22

steve y

Quote:

The exterior conditions are such a major factor they magnify proportionally as ranges increase.

Quote:

all other factors are external ballistics. And we all know that exterior ballistics isn't the rifle's job

As can be seen from our statements quoted above, we are in agreement about external factors causing groups to fall apart but I cannot grasp how simply moving the target back makes the rifle itself less accurate. Guess I'm missing something...

Say, is Warner Guns in OK? Have you dealt with them? If so, are they good to deal with?
Regards, Steve

07 December 2004, 17:08

djpaintles

Steve Y, you can believe all you want but it ain't so. For quite a while the 1000yd benchrest record small group was in the 8-10 inch range now I think it's in the 3-4" range. The 100 yard benchrest small group record is less than .01". No one has ever shot a 1/10 minute group at 1000yds but they do it frequently at shorter ranges.
The point is that in "theory" a rifle should shoot the same MOA at all ranges.....they don't. The exterior conditions are such a major factor they magnify proportionally as ranges increase. You can attend any sort of long range shooting match in the country and see this fact clearly demonstrated on any given weekend........DJ

07 December 2004, 16:52

steve y

Quote:

Theoretically a rifle that will shoot 1" groups at 100yds should be able to shoot 5" groups at 500yds. In practice it just isn't so.

Actually I believe the rifle probably is capable of it.

Remember the rifle does nothing but spin a bullet and discharge it along a path within a certain arc. It does nothing different if the target is at 100yds or 1000yds.

As long as optimal spin is imparted, any factor responsible for the bullet straying outside that arc is purely beyond the rifle's province, be it shooter error, shot conditions, velocity spread, you name it. So that group may exceed 5"@500yds but it won't be because of the rifle.

Except for velocity spread which is internal, and the fault of the load (assuming consistent striker fall and case temperature) all other factors are external ballistics. And we all know that exterior ballistics isn't the rifle's job.

I admit my statement was incorrect because it promised delivery of proportional groups but in terms of the rifle's accuracy capability, it wasn't so far-fetched. But I intended it to represent a perfect scenario to illustrate the diminished returns of increased accuracy for big-game hunting.

I'm pleased to see this thread did not degenerate into another ethics finger-pointer. Yet.

07 December 2004, 19:33

djpaintles

Quote:

As can be seen from our statements quoted above, we are in agreement about external factors causing groups to fall apart but I cannot grasp how simply moving the target back makes the rifle itself less accurate. Guess I'm missing something...

Say, is Warner Guns in OK? Have you dealt with them? If so, are they good to deal with?

Regards, Steve

How about Parallax? On a scoped rifle the with non-adjustable parallax the scope is optimized for a particular range. Their resolution in relation to the size of the target decreases with range. If you consider the sighting systems part of the rifle their relative effectiveness decreases with range.

Another consideration at really long ranges is velocity variation, small variations magnify the further out you get. At closer ranges with a 50 to 75fps variation you might still be able to shoot a .5 MOA or better group. But at longer ranges as velocity drops way off the variations become a much larger percentage of the total velocity and groups open way up. Vertical stringing at long range is often due to velocity variations. One of the reasons that Black Powder rifles can be very accurate at long range is that they can be loaded with very little shot to shot velocity variation. Plugging in a Sierra 180gr Match King at 2800fps vs 2850fps into the infinity ballistic program and a 200 yd zero shows a trajectory difference at 300yds of only .29" or less than .1 MOA. At 1000yds the trajectory difference with a 50fps muzzle velocity variation is over 12" or about 1.2 MOA. Interesting?

Sorry but I've not heard of Warner Guns. We do have some good shops though........DJ