Range report.. Is this normal?

[aimbotter]

This is my setup:

Used CCi- mini mag 40 grain round nose
tasco 4-16x-40mm scope

At 25 yards, it's dead zero. At 15 yards, it's several inches lower and at 35 yards (not shown), it's several inches higher. ***? Is this normal? Is my scope too high? No, it's not my scope. I had it on my 17 hmr and it's dead accurate 25-100 yards...

Anyone wanna shed some light? I might buy a lower mount and take off my iron sights.

 

[proven]

trajectory?

 

[MTMilitiaman]

It shoots lower at 15 yards because the optic is several inches above the bore. I experience the same thing with the RCO on my M16A4 and currently with the Kobra on my AK. You have to account for the optic's height above the bore.

It is several inches high at 35 yards because the bullet's trajectory takes it above the Point Of Aim twice--once fairly close to the muzzle--usually between 20 and 30 yards--and once downrange where the rifle is sighted in for.

For example, it is common for us to sight our hunting rifles in at 25 yards to forgo bore sighting. Once proper windage and elevation has been set at 25 yards, it is usually on paper at 100 yards and within a couple inches of where we want it to be for our respective zeroes, usually either 250 or 300 yards with centerfire rifles shooting between 2700 and 3000 fps at the muzzle.

I am guessing you'll find the rifle shoots dead-on at some range between 50 and 100 yards.

 

[elmerfudd]

Totally normal. It just takes a few yards for the bullets to rise and get up to speed.

Just joking. Some folks actually do believe that nonsense though. In reality, the bullet starts falling the minute it exits the barrel. Your sights and the barrel however are not parallel. They intersect at some point, in your case 25yds. At that point the bullets impact almost exactly where the crosshairs are. If you were to shoot from zero yards and you put the crosshairs on the bull, the bullets would impact however many inches the barrel is below the center of the scope. At 15 yards it's going to be about 40% of that distance below the bull.

 

[Kind of Blued]

Yeah, that scope looks like it's a good 3 inches above the bore. That, combined with the close shooting distances, and you've got a (completely normal) problem.

Can you get a cheek weld with the scope that high?

 

[aimbotter]

thanks a lot guys.. me still noob.. yes, i can get a cheek weld.. i'm changing my setup.. getting a lower mount

 

[swgunner]

yes it is normal, that is why you make a known distance card, or cheat sheet so that you know for example if shooting at 200yds you adjust 2 clicks up. Look into some of the books on long range shooting, they have excellent detail on how to do this. I dont have any ballistic charts for 22lr, all I have is 308 338 7x57.

 

[Kind of Blued]

Let us know how the lower mount goes. I'd like to see the before & after with targets to see how much scope height effects things. I can imagine, but I prefer not to... hurts ma head.

 

[lipadj46]

Seems like a pretty big (high mag) scope on a little carbine like that and like the others said way too high especially at close distance. Maybe along with a lower mount try a 1-4x scope or a reflex sight or just stick with the irons.

 

[geronimo509]

+1 lipad. Theres no need for that powerful of a scope at 15, 25, 35 yards.

 

[MTMilitiaman]

That big of a scope even looks ridiculous on a little .22 carbine.

I've had scopes about that big before--a 4.5-14x40 Nikon on a 10/22. But it didn't look out of place because it had a nice laminate and a 20 inch bull barrel on it.

On something that small, I think you'd be fine with a little red dot. That would be in keeping with the tacti-cool appearance of the firearm. If you want more precision, I think you could probably find a 2-7 variable that is compact and has a small enough objective bell to allow very low mounting.

 

[benEzra]

I experience the same thing with the RCO on my M16A4 and currently with the Kobra on my AK. You have to account for the optic's height above the bore.

Yup. The Kobra's different reticles allow you to compensate somewhat, which is nice (bottom of the T-bar reticle is a good close-range aiming point). The upside of the Kobra's tall sight height is that it allows you to zero at 50 and be right on at 200 without the bullet getting too far from the line of sight.

At the most recent carbine match I shot, there was a guy shooting an M4gery with a new Eotech and hadn't gotten the hang of his close-range sight picture yet, so he dropped a few rounds out of the A-zone on a couple precision stages. It definitely makes a difference.