This has me scratching my head. At 25-yard on my scoped Marlin, I was hitting within the bullseye circle. At 10-yards, I was hitting lower on the target, by a couple/few inches. I was able to reproduce this consistently with various brands of ammo. If anything, with all things being equal, shouldn't I be hitting higher instead of lower, as the target gets closer to me? During no time did I make adjustments to the scope and I was shooting from a standing, bent-over position, bracing my elbow on the shelf.

If you bullet is still rising in its flight path (arc) you will hit low on the paper. This is cause by the scope being a few inches over the bore. The scope is actually accurate at 2 different yardages, one on the upward arc, one on the downward arc. Both of these points are where the strait line (line of sight) through the scope, intersect the arc shaped bullet trajectory.

That makes sense and since the bullet was exiting the barrel a bit lower than the center of the target, that's probably what's happening. Thanks.

Your bullet's flight path is really a stretched out parabola.

Thanks again. That helps.

To expand of the detail provided, go to a ballistics calculator like Hornday's and plug in the known values of your load; velocity, bullet weight and B.C. with a default 100 yd. zero and you'll see where your bullet will impact at the muzzle, 50 yds. & 100 yds. There's even a value for scope height. http://www.hornady.c...tics-calculator

 

Two more simple diagrams for perspective:

 

 

 

I guess I was just amazed at the amount of difference in just a small difference in distance. Sure, when we're talking 100/200/300 yards, it's going to be a noticeable difference, but even for a .22, I thought it was interesting to see such a difference at such a small difference in distances (10-yards to 25-yards).

If you take the scope out of the equation, the drop will be cut in half. As Henry and others have said, the height of the scope also comes into play! Iron sights for up close rule, and here's why:

 

Short story on scopes foolin' you:

 

One day several years ago there was an idiot shooting his AR-15 clone with the latest scope on it. He parked his pick-up in the middle of a pit and got out the rifle and set-up the legs on the bi-pod and placed them right across the hood of the truck. Then he began to shoot the rifle, which sort of sounded funny. After about 3-4 shots, he stopped and was looking for where the rounds impacted the target at the berm. It was only then that he noticed bullet holes in the quarter-panel opposite where he was standing. His scope showed clear, but the rifle's barrel was so low to the trunk that the rounds went right through the quarter-panel enroute to the target!!! This is proof that it doesn't take brains to shoot, just money........

If you take the scope out of the equation, the drop will be cut in half. As Henry and others have said, the height of the scope also comes into play! Iron sights for up close rule, and here's why:

 

Short story on scopes foolin' you:

 

One day several years ago there was an idiot shooting his AR-15 clone with the latest scope on it. He parked his pick-up in the middle of a pit and got out the rifle and set-up the legs on the bi-pod and placed them right across the hood of the truck. Then he began to shoot the rifle, which sort of sounded funny. After about 3-4 shots, he stopped and was looking for where the rounds impacted the target at the berm. It was only then that he noticed bullet holes in the quarter-panel opposite where he was standing. His scope showed clear, but the rifle's barrel was so low to the trunk that the rounds went right through the quarter-panel enroute to the target!!! This is proof that it doesn't take brains to shoot, just money........

 

That's funny. I guess he doesn't need those stick-on fake bullet holes on his truck.

That's funny. I guess he doesn't need those stick-on fake bullet holes on his truck.

 

NOPE! And I wonder if he ever reported it to the insurance co. or just had it fixed on his own?

 

I've seen a lot in 40 years of shooting. Scopes mounted backwards, .22 rings on a .30-.30 rifle crack right off from recoil, guns reassembled without a mainspring, even completely new .40 S and W rounds falling-out of the muzzle of a .45 ACP after the owner loaded the mag with 2-3 .40's and then put a .45 into the chamber before I could yell STOP! Good thing he didn't fire the gun with 2-3 .40 cal. rounds in the barrel! That would have been a wake-up call!

I guess I was just amazed at the amount of difference in just a small difference in distance. Sure, when we're talking 100/200/300 yards, it's going to be a noticeable difference, but even for a .22, I thought it was interesting to see such a difference at such a small difference in distances (10-yards to 25-yards).

 

You would be amazed how much time some people (myself included) agonize over their zero's, holdovers, and muzzle offsets. For example I know that with my rifle, with a scope height of 2.8", a 55gr bullet moving at 2900ft/s at 10ft from my muzzle and a 200yard zero, I will hit -2.8" at muzzle, -1.33 at 25, +0.75 at 100, +1.46 at 150, -8.8 at 300 and -28 at 400 (ouch).

You would be amazed how much time some people (myself included) agonize over their zero's, holdovers, and muzzle offsets. For example I know that with my rifle, with a scope height of 2.8", a 55gr bullet moving at 2900ft/s at 10ft from my muzzle and a 200yard zero, I will hit -2.8" at muzzle, -1.33 at 25, +0.75 at 100, +1.46 at 150, -8.8 at 300 and -28 at 400 (ouch).

 

 

Yea, that's a bit more than I need to know . As long as the bullet hits what I'm aiming at, that's 95% of the battle for me. How it got there is immaterial .

Yea, that's a bit more than I need to know . As long as the bullet hits what I'm aiming at, that's 95% of the battle for me. How it got there is immaterial .

 

Actually - if you're shooting rifles, it's basic ballistics that you SHOULD know. The "I don't need to know that as long as it gets there" attitude does not sound right to me. You're responsible for where that bullet impacts.

Actually - if you're shooting rifles, it's basic ballistics that you SHOULD know. The "I don't need to know that as long as it gets there" attitude does not sound right to me. You're responsible for where that bullet impacts.

 

 

I undestand that, I really do. Even more importantly is knowing what's beyond your target. What I was attempting to make humor about was the level of detail that Vlad G was going into.

I undestand that, I really do. Even more importantly is knowing what's beyond your target. What I was attempting to make humor about was the level of detail that Vlad G was going into.

You DO need to know that much detail. I find that with the many different calibers and cartridges I reload, I have to keep track of all their ballistic data. Even for pet loads that I have reloaded consistently for years, I still roll up a little piece of paper and put it in my ammo box with the different POI's @ 100, 200, 300 yds., especially for hunting loads. (Some folks tape the data to the buttstock of their rifles for a quick glance update.) For example, my 6mm varmint load is zeroed for 200 yds., yet it strikes 6.1 inches low at 300 yds. That can easily be a miss on a woodchuck or a crow at that range if I don't account for it. At the 400 yd. mark, that same 85gr. HPBT bullet drops 18".

You DO need to know that much detail. I find that with the many different calibers and cartridges I reload, I have to keep track of all their ballistic data. Even for pet loads that I have reloaded consistently for years, I still roll up a little piece of paper and put it in my ammo box with the different POI's @ 100, 200, 300 yds., especially for hunting loads. (Some folks tape the data to the buttstock of their rifles for a quick glance update.) For example, my 6mm varmint load is zeroed for 200 yds., yet it strikes 6.1 inches low at 300 yds. That can easily be a miss on a woodchuck or a crow at that range if I don't account for it. At the 400 yd. mark, that same 85gr. HPBT bullet drops 18".

 

 

 

Trust me. For now, with my current usage, I need not know any of that data. I do however, appreciate the insight and stats you've provided.

I have to write things down. I find I forget a lot of stuff at my age. When I wrote that response it dawned on me I forgot how many grains of IMR4350 I use to achieve the initial velocity for that particular load. I used to have everything memorized. I remember some loads, not all.

I was watching a show on TV once that showed sniper shots by our military forces. In one of the scenes the sniper took a shot but the bullet actualy impacted a wall similarly to Daves post above. The scope was on-target, but the barrel was just below the top of the wall they were shooting behind.

 

I had a similar experience as the OP did. I had a red dot on my little Ruger 10/22, was perfect at 25 yards. Did OBRAMS with it one day and found I had to shoot about 6" high for targets about 7 yards from me to actually hit where I wanted to. I didn't want to mess-up the adjustments I had set for 25 yards since that is what I normally use it for.

I had a similar experience as the OP did. I had a red dot on my little Ruger 10/22, was perfect at 25 yards. Did OBRAMS with it one day and found I had to shoot about 6" high for targets about 7 yards from me to actually hit where I wanted to.

 

Ah .. secondary zero's. Odds are your 25yard zero was a secondary zero, with the primary somewhere really close to the muzzle. Basically you might have been zeroed at 3ft the bullet keeps rising to be 6" high at 7 yards, and then falls back into zero at 25. It is useful to know your primary and secondary zero, and some of the most popular AR zero distances are based on it.

 

For example the 50/200 zero for ARs depends on the fact that a primary zero at 50 yards is also a pretty damn good secondary zero at 200 yards. This results in less the 3" bellow or above the site line from muzzle to about 250yards which is a pretty damn nice thing. Of course the gun isn't actually PERFECTLY zeroed at both 50 and 200, one of them will be very slightly off depending which one you picked to zero at and your bullet weight and speed, so it is handy to do a initial zero 50, then go refine it for 200, it is quicker that way and more precise because a tiny bit off at 50 is a lot off at 200.

If you bullet is still rising in its flight path (arc) you will hit low on the paper. This is cause by the scope being a few inches over the bore. The scope is actually accurate at 2 different yardages, one on the upward arc, one on the downward arc. Both of these points are where the strait line (line of sight) through the scope, intersect the arc shaped bullet trajectory.

This For instance an Ar-15 (m-193 ammo) Sighted in at 50 yards will be on at 300

This For instance an Ar-15 (m-193 ammo) Sighted in at 50 yards will be on at 300

 

Negative, sir. It's 50/200. 25/300.

 

 

Negative, sir. It's 50/200. 25/300.

 

Nick is correct. If you look at the graphical representation of the bullet's arcing trajectory, you will see that a close zero corresponds to a farther secondary zero. A further away zero corresponds to a closer secondary zero.

Negative, sir. It's 50/200. 25/300.

 

Correct..my mistake

And you really should actually check those numbers in your rifle. the 25/300 and 50/200 are approximations and they will vary from bullet to bullet even at the same weight and velocity, nevermind with your barrel, sight off set, and all those bits. For example with the ammo I just zeroed my rifle for a match it is more like 40/200, or 50/225.

And you really should actually check those numbers in your rifle. the 25/300 and 50/200 are approximations and they will vary from bullet to bullet even at the same weight and velocity, nevermind with your barrel, sight off set, and all those bits. For example with the ammo I just zeroed my rifle for a match it is more like 40/200, or 50/225.

 

It's meant as a Battlesight Zero, not necessarily a Precision Targeting Technique Minute of Bad Guy not MOA

yeah the problem is what happens further out, because 50/200 is pretty good up to 250 even if you change your ammo a bit, but it it can be 10" difference or more at 400 by being an inch off at 200, which when you add it to the 28" its gonna drop anyway, it becomes a real difference. Of course, if you never shoot at that distance (and who out side competition of Afghanistan does?) indeed it doesn't matter as much.