I still get confused about MOA and holdover

T

tpcollins

New member
I understand inches drop and MOA drop using an adjustable target turret. But for simplicity sake, let's say I'm zeroed at 100 yards and the inches drop at 200 yards is 8", with an approximate 4 MOA drop. If I had a target turret that was 1/4 MOA per click, I'd just turn it up 16 clicks to shoot at 200 yards (I know 1 MOA is 1.047").

But if I don't have a target turret and want to use Kentucky windage at 200 yards, I would aim 8" above the intended target spot instead of 4", correct? Thanks.
 
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You lost me...
You're zeroed at 100. You say you have 8" drop at 200. Then you say it's an "approximate 4 moa drop".Drop isn't linear, if you have 4" from muzzle to 100 yards, then it's a lot more than 8" at 200.

If you're zeroed at 100, what is your drop from 100 yards to 200- is it 4", or 8" in your example?

If it's 4" from your zero, you hold 4". If it's 8" from your zero, you hold 8". You don't hold for "total" drop- it's drop from whatever distance you're zero'd at.
 
Assuming that you are going to use the rifle on something like deer, you might sight it in for about 2 1/2 inches high at 100 yards to maximize the distance you can hold dead on without worrying about holdover. For most cartridges it would be somewhere between 250 and 300 yards before you have to start holding over.
 
I understand inches drop and MOA drop using an adjustable target turret. But for simplicity sake, let's say I'm zeroed at 100 yards and the inches drop at 200 yards is 8", with an approximate 4 MOA drop. If I had a target turret that was 1/4 MOA per click, I'd just turn it up 16 clicks to shoot at 200 yards (I know 1 MOA is 1.047").

But if I don't have a target turret and want to use Kentucky windage at 200 yards, I would aim 8" above the intended target spot instead of 4", correct? Thanks.
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If you know that your point of impact at 200 yards is 8 inches below your point of aim then you aim 8 inches high when shooting at 200 yards. If you are using your scope to adjust then you have to convert the 8 inches at 200 yards to MOA (4 MOA) and adjust the scope the 16 clicks.
 
But if I don't have a target turret and want to use Kentucky windage at 200 yards, I would aim 8" above the intended target spot instead of 4", correct? Thanks.
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If I understand your question,Yes.
Draw a sketch of a long,skinny triangle..Make it about 6 in long. You might mark it in about thirds along the length.
MOA is "Minute of Angle" That's 1/60 of a degree.Thats the angle at the skinny end of the triangle. As you said,the 1 MOA angle spreads 1.047 at 100 yds. Lets make this easier and call it 1 in. At 100 yds. The geometry is proportional.
That means it will spread 2 in at 200,3 in at 300,and so on.
Sight adjustments make changes in ANGLE . MOA,or mils,or whatever.
The effect on the target,that you want in INCHES,is controlled by the distance to the target . The INCHES on target is controlled by the ANGLE over a DISTANCE.
I think you have it,and just wanted it confirmed.

Now,you are getting additional suggestions. In most centerfire hunting rifle situations,especially relying on some Kentucky windage holdover..a dead on 100 yd zero is harder to work with hunting. For a typical 308 type rifle,and most others,you will get a dead on 200 yd zero if you sight in about 2 1/2 in high at 100yds. It might be 8 in or so low at 300 yds.Out to 250 or so,its pretty much point and shoot at a heart/lung shot.
Of couse,you have to fine tune this to your exact cartridge,and its best to confirm it on the range. I feel a lot better with an actual 200yd or whatever zero I'm looking for versus so much high at 100 yds.
 
If you know that your point of impact at 200 yards is 8 inches below your point of aim then you aim 8 inches high when shooting at 200 yards.

If you are using your scope to adjust then you have to convert the 8 inches at 200 yards to MOA (4 MOA) and adjust the scope the 16 clicks.
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Thank you Shooter PRS, that's exactly what I was looking for.

(I'm aware that 1 MOA is 1.047" at 100 yards, and 1 MOA at 200 yards is 2.094", etc., etc).
 
To answer your other question:

tpcollins said:
But if I don't have a target turret and want to use Kentucky windage at 200 yards, I would aim 8" above the intended target spot instead of 4", correct? Thanks.
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Yes.

What type of reticle are you using? If it's a simple duplex reticle, then you are likely going to have to use Kentucky Windage. That said, there are holds that can be used, depending on the specific duplex reticle.
 
Yes.

What type of reticle are you using? If it's a simple duplex reticle, then you are likely going to have to use Kentucky Windage. That said, there are holds that can be used, depending on the specific duplex reticle.
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Thanks Unconventional,

I'm aware of using the reticle spacings at maximum magnifications. I have target type turrets on my two main deer rifles. I was just going to print out a ballistics chart for my brother-in-law to use that doesn't have a target turret. Thanks again.
 
Assuming that you are going to use the rifle on something like deer, you might sight it in for about 2 1/2 inches high at 100 yards to maximize the distance you can hold dead on without worrying about holdover. For most cartridges it would be somewhere between 250 and 300 yards before you have to start holding over.
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Just complicates things. Zero almost any modern rifle cartridge at 100 yards and you don't have to worry about holding high until you're past 300 yards for hunting. Zeroing 2.5" high at 100 may mean that you have to remember to hold low at some ranges which sure isn't natural. Much beyond 300 yards you have to hold over anyway. If you can hold 6" high at 400 yards you can hold 12" high just just as easily.

let's say I'm zeroed at 100 yards and the inches drop at 200 yards is 8",
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Is this a hypothetical question? Most rifles zeroed at 100 yards will only be about 2" low at 200 yards and 8-10" low at 300 yards. If I'm taking a shot between 0 and 200 yards I simply aim at the center of an animals chest. If I've over or under estimated the range a little I'll still get a hit. If the animal is anywhere between 200 and 300 yards I simply hold at the top of the back. The bullet will drop 2"-8" at those ranges and still be in the kill zone.

You normally don't have to worry about twisting dials, aiming high, or using a scope with dots until you get beyond 300. At those ranges accurate range estimation is important and a range finder is a very good idea. If you "guess" the range is 400 and hold over for that range, and it is actually 450 yards that is enough for a miss.

if I don't have a target turret and want to use Kentucky windage at 200 yards, I would aim 8" above the intended target spot instead of 4",
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For target work with a small bulls eye aim 8" high for the bullet to land close to the bull. For hunting an animal with a 10-18" kill zone it is less critical. On an elk with an 18" or larger kill zone you could still aim dead center and be in the kill zone. On a varmint hunt you need more precision.
 
...zeroed at 100 yards and the inches drop at 200 yards is 8"
But if I don't have a target turret and want to use Kentucky windage
at 200 yards, I would aim 8" above the intended target ... [right?]
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I was going to invoke Newtonian physics with a Langrange expansion polynomial
using an inversion matrix, but then I thought "...what the heck...?

"Yes"
 
Just complicates things. Zero almost any modern rifle cartridge at 100 yards and you don't have to worry about holding high until you're past 300 yards for hunting. Zeroing 2.5" high at 100 may mean that you have to remember to hold low at some ranges which sure isn't natural. Much beyond 300 yards you have to hold over anyway. If you can hold 6" high at 400 yards you can hold 12" high just just as easily
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jmr,with all due respect,I don't think your numbers work out for most hunting rifles.
I went to Hornady's site and used their calculator.I'll provide the URL.

I entered a1.5 in sight height,2700 fps and a G-1 BC of .430 Those numbers are not far off of a 165 gr 308 load or similar.

A 100 yd zero would give 14 in + drop at 300 and 23 in drop at 350.

Agreed a 2.5 high at 100 yds places the midrange trajectory above the line of sight. The trick is to decide what you can live with per the target area of your prey.
The calculator is free to use,no sign up required.
Enjoy! And Thank You,Hornady!

https://www.hornady.com/team-hornady/ballistic-calculators/#!/standard
 
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You are making a chore out of this. Don't know what your shooting but zero 3" high at 100 yds and hold pretty much dead on to 200 yds then 300 yds.
 
Forget the MOA/PDQ/ASAP and all that other alphabet stuff and hold over the amount of the drop. The only rounds I zero at 100 yards are 17 HMR and 300AAC,everything else is 1-3" higher than POA.
 
It seems that too many people want to condemn the amount of drop and not just answer the damn question except for a few. This is actually for my brother-in-laws muzzleloader which really does have a drop of a bit over 12" with a 100 yard zero.

I thought with my "for simplicity's" sake I would use the 8" drop as a hypothetical question to keep some heads from exploding. But as usual, if I get a dozen responses I'll get the 2 or 3 correct answers for the question I actually asked. Thanks.
 
"...MOA drop..." There's no such thing. One MOA is a 1" group at 100 yards. 2" at 200 yards, etc. There's no dropping by a 1" group per distance.
"...a target turret..." That makes no difference either. The 1/4" per click matters though.
Anyway, a great deal depends on the cartridge, barrel length and bullet weight.
Federal Premium ammo with a 165 grain bullet with an MV of 2700 FPS, out of a .308, sighted in dead on at 100, will drop about 4" at 200. Sighting in 4" high at 100 will put you on target at 200. Drops like a brick past 200. Although I suspect Federal's site might be incorrect. 165's usually drop like bricks past 300.
 
I keep it simple with what I call the 7..20..40 rule. Assuming a muzzle velocity of about 3000 fps, which all my rifles but the 220 Swift have, sight the rifle at 200 yards (which is about 1.5 inches high at 100). Then the drops are 7 inches at 300yards, 20 inches at 400, and 40 inches at 500. Admittedly, the 40inch drop at 500 yards isn’t very useful, but the 20 inch drop at 400 has been useful from time to time on deer and pigs.

For a couple of years recently, I switched to a 100 yard zero, but after so many years of sighting in at 200 yards and using the 7..20..40 rule, I went back to the 200 yard zero. It’s simple and useful and works for anything with a MV of around 3000 fps. Play around with a ballistics app and you’ll see what I mean. The same logic works, though with slightly different drops, for 2800 to 3200 fps. My 220 drops, at 3800 fps, are 5..15..30ish.
 
Holy crap, whatever you do, do not listen to this:

T. O'Heir said:
"...MOA drop..." There's no such thing. One MOA is a 1" group at 100 yards. 2" at 200 yards, etc. There's no dropping by a 1" group per distance.
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T. O'Heir is limiting himself to a pretty narrow and ignorant understanding of applications for measurements in MOA.

It's much more than a way to measure groups, for cryin' out loud.

tpcollins, I'm so sorry that your simple question had to be met with all kinds of speculation about "why does your rifle drop so much" and "most rifles do this" and such. I hope you found your answer through all the noise, especially the bloviating nonsense I quoted above.

The hypothetical rifle has a 4 MOA drop at 200 yards. You have it right.
 
In post #5 ,I said "If I understand your question,the answer is "yes".
The simple answer you asked for.

Then,I attempted to explain MOA as angle,and angle over distance yields inches.

Give a man a fish vs teach a man to fish.Which is the answer to "I still get confused"

A gentleman,in good faith,offered some drop figures based on a 100 yd zero for a typical hunting rifle. IMO,those numbers were misleading.
My comments regarding drop figures were in response to his post.
I specifically addressed my response to jmr and his numbers.

The notion that a common 308/30-06 type rifle sighted in dead on at 100 yds will only drop 8 to 10 in at 300 will be good for broken leg shots.
If the general rule of approx. 2 in high at 100 yds gives a 200 yd zero works(it does) then how would a 100 yd zero be only 2 in low at 200? 2 in at 100 is 4 in at 200.

Once again,in the spirit of "teach a man to fish" I offered the link to the very useful Hornady program.Then folks,even with muzzle loaders(if they can find a BC) can run their own range cards. Hornady gives you a nice,small format one to tape to your sling.

Head expoding??? :) Hardly. I'm not the one who needs an answer to the question.
I'm giving you my best to answer your question.

Thank you for your appreciation.

Unconventional,Post 17 : Agreed.
 
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After all the back and forth verbiage on drops, it should be easier to understand why i’ve long been a fan of the 200 yard zero and the related 7..20..40 inch drops. It’s easy to remember, easy to use, and requires no turret twisting or heavy thinking. For target shooting, a couple of my rifles are actually sighted in at 100 yards, but I set the turrets for a 200 yard zero when hunting. Keeping things simple works best for me.
 
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