So I am confused. POI change on AR from 50-100 meters

[DPris]

As I've posted before, I did a four-gun project to debunk that 25-yard AR zero earlier this year.
All were zeroed dead on at 25 yards, then fired off the bench at 50, 100, and 200 yards.
The three with optical sights shot 5-9 inches high at 100 yards with four different bullet weights, the 20-inch Sporter A2 with irons only ran about 2-3 1/2 high at 100. It also showed markedly lower than the other three at 200 yards.

The Stag M3 with 1 in 9 twist and an Aimpoint ran 5 5/8 inches to 7 1/2 inches above point of aim at 100.

Barrel lengths, velocities, sighting types, bullet weights, twist rates, and sight heights can all make a difference, and if you want to be right on at 100 yards, you zero at 100 yards, with each individual gun.

I also found some slight variations in windage between the 25-yard zero and 100 & 200-yard impacts.
Denis

 

[jbkebert]

DPris thanks for your efforts on debunking this myth. I as a whole agree with your findings. I have never had a rifle gain 5-9 inches in height from a 25 yard zero to 100 yards. Perhaps it has a little to do with optics height on the AR platform.

Like I said I usually start at 25 yards for ease and speed of getting pretty close. At 25 yards I can see bullet holes with my eyes. I can fire three shots even fairly quickly look over see my impacts. Make adjustments to get in a pretty close ball park. I don't bore sight so this generally saves on ammo.

But like I said before from being within a small degree or dead on at 25 then moving to 100. I completly understand the need to make adjustments to get a 100 yard zero. But when I am shooting at 100 yards and I am not even on paper that is 20" square something is wrong. I am a little under familiar with this gun it being somewhat new to me. Yet my game console growing up was a .22 rifle and a fishing pole. I have fired thousands of rounds in my life but never had a setup behave like this.

I am going to just skip over the red-dot thing altogether. I demand more accuracy than it can give me at any range. I have a feeling I could buy the finest model aimpoint or eo-tech offers and I would still be pissing and moaning about lack of precision at 300 yards. Call me crazy...

 

[DPris]

I was a slow sell on dots, till I stuck the Aimpoint on the Stag.
I still prefer real optics with magnification for long range shots, but I've got the Stag set up for close-to-intermediate distances & quite like it.
Best I've been able to do with it off the bench is 5 shots into 1 7/16 inches at 100 yards, with Black Hills OT 77-grain military loads. That's pretty good for my eyeballs & no magnification.

The key to zeroing and/or accuracy testing at 100 or farther is to dial the dot down till it's just visible enough to see. Once you get your load & zero settled in, you can dial the dot back up for quicker acquisition.

The point of my 25-yard zero testing was to show quite clearly that it's not adequate across the board as a general rule & can't be counted on.

Between the four guns there were three 16-inchers, one 20-incher, one pencil barrel, one factory "heavy" barrel (or as close to a heavy barrel as Colt puts on their LE ARS), one M4 stepped barrel, one government profile/weight (20-incher), one standard A1 carry handle military configuration iron sight setup, one Aimpoint, one Trijicon, one old 4-power fixed scope on top of a carry handle, four different stock configurations, one free-floated barrel, one standard carbine handguard, one custom handguard, one small-diameter drop-in aftermarket handguard, one standard 20-inch factory/military handguard, two barrels with 1 in 7 and two with 1 in 9 twists.

That's a pretty good range of barrel types & sight types & heights.
Four bullet weights, 50, 55, 68 and 72.

The idea that you can take any AR, zero it at 25, and call it good to infinity is just bushwah.
In my book, you zero at 25 just to get the gun on paper so you can do the real zero farther out.

At 200 yards I was getting hits as high as 13 inches above POA.
Denis