We have had some shooters here shooting a lot of 22 ammo in different rifles, and both 50 and 100 yards.

Some of them actually shot better groups at 100 yards than at 50 yards - with the same rifle and ammo???

What do my friends here think??

Hi Saeed,

That could very well be. That's why we always shoot at different yardages to see what the bullet is actually doing.

Now your telling me that I have to go to the UAE to find 22 cal ammo. Great!

HAVE A NICE TRIP MAC!!!I need about 25,000 rounds for my store please.

Hi Saeed

Are they shooting in a tunnel, or outside?

Tom,

All our shooting is in an underground tunnel.

quote:

Originally posted by Saeed:
Tom,

All our shooting is in an underground tunnel.

Hi Saeed

Curious, I'm accustomed to thinking of a cone of dispersion with a more-or-less consistent trajectory. It suggests an instability that corrects itself over time. If the dispersion was affected by air currents, the bullets would have to encounter an opposite current somewhere downrange of 50 yards for it to be reversed. Maybe there is some sort of swirl in the tunnel air?

Good morning, Folks;

I have heard some high power folks say they think some of their loads do that, but darned if I can see how it would work. There would have to be some corrective force applied downrange and I don't know what it could be.

I have never seen it.

Y'all be good.

horsefly

Subsonic DOES work better at most ranges due to not breaking then transcending the "sound" barrier....

.

As I understand it, for groups to get better is mathematically impossible. The firearm’s grouping may improve relative to MOA but not the absolute group as measured in inches or millimeters unless an outside influence is present. But, once a group is fired at 100 yards/meters that measures 1 inch, it cannot fire a smaller group at a longer distance. The MOA of the group might improve, however, as the bullet further “settles down.”
The testing that was done at the Houston Warehouse by some of the best smallbore shooters in the world proved that the dispersion was linear as to distance. If there are no outside effects on the bullet, it will shoot linearly at distance. 1” at 100, 2” at 200, and 3” at 300 yards, etc. Or in the case of those shooters, they produced many groups at 100 yards of less than 0.100”. Sometimes much less. Serious shooters, they shot from a 700 pound bench with a 6” steel top. Shooting took place from 1975 thru 1981.
Would have loved to have been there.

I generally agree with 7X. However, I recall reading in "Any Shot You Want" that recessionary(?) velocity, which is the rear end of the bullet rotating about the centerline, or the lack thereof can result in improved accuracy at longer distances. Improved accuracy does not mean smaller groups.

The idea seems to defy any logic.

quote:

Originally posted by Saeed:
The idea seems to defy any logic.

Hi Saeed

Do the targets have any bias towards vertical or horizontal dispersion?

I've noticed that occasionally a load will appear to group better at longer range. It does take some bullets a little bit longer to fall asleep, but there is nothing that will make them actually shoot a smaller group at longer yardage. If you'll average out enough groups you will prove this to yourself. Although, only comparing two or three groups at each range can show deceiving results and can lead to erroneous conclusions.

quote:

Originally posted by TomP:

quote:

Originally posted by Saeed:
The idea seems to defy any logic.

Hi Saeed

Do the targets have any bias towards vertical or horizontal dispersion?

I'm curious what the difference in groups was to begin with, and like Swampshooter I think the sample size matters too.

Gentlemen,

We shoot an extraordinary amount of 22 ammo here, in various types of rifles.

We also have about 70 different types of 22 ammo from different manufacturers.

Some are match grade from Eley and Lapua, and some are from different manufacturers.

There is no way to tell if the strings are more vertical than horizontal, as some of the groups are terrible.

Another problem I find is the inconsistency of the accuracy of some of the ammo.

I have some data, and I will post it once I have had a chance to put it on the computer.

There is a stability thing that may be involved .
I can never remember the name but a bullet 'wobbles ' a bit until it gets some distance from the muzzle.Then it settles down.
Cartridges such as the 6.5x55 or 7x57 with heavy bullets often show this . So the 100 yd group may be 1.00 " but the 200 yd group may be 1.5 " .That may make you think iot defies logic !!.

Hi Saeed

An experiment...set up two targets at 50 yards and 100 yards, poke holes through the centers and line them up with a laser and level. Now shoot groups with the idea that any difference in the presumed cone of dispersion should be measurable.

quote:

Originally posted by TomP:
Hi Saeed

An experiment...set up two targets at 50 yards and 100 yards, poke holes through the centers and line them up with a laser and level. Now shoot groups with the idea that any difference in the presumed cone of dispersion should be measurable.

Might try this when I get back early next year.

Taking a school break to the mountains for a couple of weeks.

A reading of this paper may shed some light on the how can some bullets group better at 100 yds vs 50 yds.
www.nennstiel-ruprecht.de/bullfly

muck

My opinion, and I have absolutely no scientific knowledge to back this up, is that the rifle scope's parallax free distance may account for this seemingly impossible discrepancy. Possibly your scope was parallax free at 100 yards, not at 50.
I have had the same experiences over the years:
A Model 70 pre-64 .257 Roberts with a Leupold VXII 3-9x40 in the late 1970's. The rifle was very accurate for a stock rifle. In four or five witnessed cases it shot a load at @.75" at 100 yards, .5-.6" at 200 yards.
A Ruger 77ST 7x57 with a Leupold VXII 3-9x40 from the mid 70's. Several loads shot better at 200 yards than 100 yards. On one occasion, I fired a slightly less than 1" group at 100 yards, then fired a 5 shot group, same day, same load, at 200 into .5" and my last three rounds into .68" at 200.
My current Remington Model 700 Classic 300 H&H with a Leupold VXIII 3.5x8 rarely makes the magic 1" group size at 100 yards. But it often shoots between 1.5" to 1.8" at 200 yards.
If yawing were the cause, I believe the holes would exhibit a keyhole profile. It's not that the entire bullet goes in a circle, just the front or rear. Or so I understand the concept to be.
But this "impossibility" occurring does make for interesting discussion. Thanks for bringing it up.