Guys - I need someone to help me understand in simple terms please how I convert the chart below for use with my current scope...The scope on my Remington 5R is a Zeiss Conquest with adjustable turrets that reflects that each click represents 1/4 MOA at 100yds....Using the chart below if my rifle is zeroed at 200 yards how many “clicks” would I need to move my up/down turret to achieve a zero at 400 yds (using the chart below).....Sorry to have to ask but this is all brand new to me....Thanks Mark

I am confused by the MOA column, but the inches column indicates that with a 200 yard zero the point of impact at 400 yards will be 24 inches (23.99, actually) below the point of aim. 24 inches is 22.9 minutes of angle (24 ÷ 1.047). At 400 yards, one click of your scope will equal 1 MOA. Therefore to have your point of impact be at your point of aim at 400 yards, dial up 23 clicks.

Added: I figured out the MOA column. The values in the MOA column can be divided by your scopesight’s adjustment values to get the number of clicks necessary as well.
5.72 ÷ 0.25 = 22.88 (~23)

If you wanted to adjust your sight to shoot at 500 yards, the calculations would be:
48.70 ÷ 1.047 = 46.5 MOA; at 500 yards one click equals 1.25 MOA, so 46.5 MOA = 37.2 (~37) clicks

Or much simpler:
9.30 MOA ÷ 0.25 MOA = 37.2 (~37) clicks

Sigfreund - Thanks Sir - again for your help...The MOA column was what was confusing me also...I will use the inches column as you identified as my guide...Hoping to get to go shoot next week on a range that goes out to 800yds and I wanted to have a clue as to where to start with the set up I have...


Greatly appreciate your continued support Sir...Mark

You're welcome.
But I did figure out the MOA column.
Use the value there for the range you're shooting at, and divide by 0.25 to get the proper number of elevation adjustment clicks. I added a couple of examples above.

If 1 MOA at 100 yards is 1.047 inches, then 1 MOA at 400 yards is 400/100 x 1.047 = 4.19 inches.

Bill

Makes sense now. Thanks guys. Thanks for explaining the chart to my understanding based on the scope set up I have...GREATLY appreciate your time and help...Mark

In addition, your scope's elevation adjustment knob may already be marked in minutes of angle along with 0.25 minutes. If so, just dial up by the amount listed for your range in MOA.

For example, at 400 yards, dial up to the 5 3/4 mark.
For 500 yards, dial up to the 9 1/4 mark.
For 800 yards, dial up to the 23.0 mark. Depending upon how your scope is calibrated, 23 MOA up may be more than a full 360 degree turn of the dial, and you'll have to start the count over at, for example, 20 MOA.

SF - You are right. My turret knob is marked like you said so I will ne able to use the MOA column...Here is a photo of the turrets on this rifle’s scope....Mark



Better photo

Well, that will make it easy.
All the best, and let us know how everything turns out. Long range shooting is great fun.

quote:

Originally posted by sigarmsp226:
Guys - I need someone to help me understand in simple terms please how I convert the chart below for use with my current scope...The scope on my Remington 5R is a Zeiss Conquest with adjustable turrets that reflects that each click represents 1/4 MOA at 100yds....Using the chart below if my rifle is zeroed at 200 yards how many “clicks” would I need to move my up/down turret to achieve a zero at 400 yds (using the chart below)...

Allow me to clean up a few things. Your statement about your scope clicks representing 1/4 MOA at 100yards is incorrect. The distance is irrelevant, since an MOA is angular measure. A minute of arc (or angle) will represent a different subtension at different distances, but an MOA is an MOA regardless of distance.

In a ballistics chart, you should always ignore the inches column, it's only used to impress people. The MOA or the MIL columns are the only ones that count. Now if your scope is an SFP design, the MOA on the dial will always be 1/4 MOA per click, but the reticle marks will only be correct at one magnification, usually the highest mag. On an FFP design, the reticle subtensions will always be correct, but the reticle size will vary. The dials are the same for an FFP or an SFP.

When shooting at longer ranges, we only concern ourselves with the MOA or MIL offset indicated on the ballistics chart matching the distance at which we are shooting. For instance, my match rifle has a zero at 1000 yards. If I want to shoot at 600 yards, the ballistics chart says I need to come down 20 MOA. That's too full turns on the 10MOA per rev of my scope. Easy peasy. I could not care less how many inches that represents, and I would not know if that's inches at 600 yards or 1000 yards. All I care about is the angle and that's MOA or MIL.

When I develop a load or do some other work at 100 yards, I use a thermometer target, 4 feet high. On it I draw a vertical line, place a dot at the bottom and mark off inches from 24 inches on up. At 100yards, an MOA is about an inch. I need 30 MOA from a 100 yard zero to get to 1000. So, I aim at the dot at the bottom of the line on the target and adjust the scope until my bullets hit 30 inches up. It also allows me to get the windage correct.

Forget inches, think MOA. Don't waste time converting to inches.

Nikon - Thanks Sir for your feedback and correction of my statement. My plan will be to use the MOA column only since this is my first shooting venture shooting past 200 yds. This rifle’s elevation turret is current set at 200 yards for zero thus the reason I am using this simple “plug your numbers in” chart for the specific round I am shooting.....

I appreciate all of the feedback, comments, and direction. I would rather ask and understand here vs. getting down to shoot and missing everything beyond 200-300yds....I will share my results post shoot. If I really like this shooting discipline this 308 will soon have a brother rifle because after shooting this rifle 20-40 times my 61 year old, twice surgery shoulder - gets a little sore and stiff for a few days....Not complaining as it is a sore that makes me smile knowing why it is there....

Thanks Again - Happy New Year...More to come..Mark

Yes, print a chart with MOA only and just get used to thinking in terms of MOA not inches. Whatever the MOA on the chart says, just multiply by 4 to get the number of "clicks."

quote:

Originally posted by sigarmsp226:
Nikon - Thanks Sir for your feedback and correction of my statement. My plan will be to use the MOA column only since this is my first shooting venture shooting past 200 yds. This rifle’s elevation turret is current set at 200 yards for zero thus the reason I am using this simple “plug your numbers in” chart for the specific round I am shooting.....

I appreciate all of the feedback, comments, and direction. I would rather ask and understand here vs. getting down to shoot and missing everything beyond 200-300yds....I will share my results post shoot. If I really like this shooting discipline this 308 will soon have a brother rifle because after shooting this rifle 20-40 times my 61 year old, twice surgery shoulder - gets a little sore and stiff for a few days....Not complaining as it is a sore that makes me smile knowing why it is there....

Thanks Again - Happy New Year...More to come..Mark

Sorry to be so late coming back here; work has been a bear.

Let me take this a few steps further in the hope that it will help you focus on the concept. Long range shooting is not difficult when it comes to elevation. There are plenty of sites and apps that will calculate the numbers for you but you need to start with accurate data.

In order to plot a precise drop chart or ballistics table, you need to know the exact muzzle velocity of your ammo, out of your rifle. I use JBM ballistics and I feed it all the proper data. MV, bullet specs or use their stored specs, elevation where you live/shoot, temperature, humidity, distance between he bore of the rifle and the middle of your riflescope, zero distance, etc. One you have that straight, get the printout.

Zero the rifle at the distance you specified on the chart. If that is the shortest distance you will ever use, set the zero stop on your scope to that distance. This way, whenever you dial and forget how many revs you have and so on, you can always dial back down to the zero stop and then dial up to your distance according to the chart. Now, that chart of yours will be an approximation, and its precision will be dependent on the precision of your input. The two most incorrect pieces of input data are muzzle velocity (MV) and bullet BC. If you are sure of your MV, then go out and check the precision of the predictions by shooting on paper, because the target never lies. It can mislead you, but in the end, it's the nub of the issue. Once you have a precise MV, the BC value will be the one that may need adjusting and the target will guide you. Most published BC values are inflated to one degree or another and it is quite common to adjust it downward a bit.

Set up at 100 yards, zero the rifle, measure the MV and plug all that data in. Then look at what it says for 200, 300 and so on. Add the required MOA on the elevation dial and take shots at the new distance. Then measure how much off you are on elevation. Usually, you will be lower than expected, but for the shorted distance, not so much. Once you have figures for 200, 300 and so on, you can play with the ballistics app by changing the BC value until you get a closer match to actual. Once you have that, lock it down, you're good to go. For the longer distance, I would suggest you use the G7 BC value rather than the G1. The G7 number will be a lot smaller than the G1 figure, but it's not the same scale, so to speak.

In real life, I have a detailed drop sheet for my F-TR match rifle. The zero distance is at 1000 yards, but that's also a 100 feet of elevation an 80 degrees and 50% humidity. From day to day, I have to adjust the zero to account for environmental variations, and sometimes even on the same day, if it's a long match. I have my zero set just under 600 yards. This way I know exactly where the scope is set and can recover when my brain farts. (I'm several years older than you, and I can tell you it does not get better, so use all the tricks you can.)

As a rule bullets fly faster the hotter it gets. If it's cold in the morning when the first shot goes down and 4 hours later it's warmed up 40 degrees, the bullet will be going faster in the afternoon.

The bullets fly faster as the humidity rises. The effect is not as dramatic as with the temperature change, but it's there. So cold and dry is slow, hot and sticky is fast.

When I travel to other venues, I use JBM to help predict the ballistics for that location. Going from sea level in South Texas in July to 7000 feet ASL in Raton, NM in October will bring some difference. Same as going to shoot in Ottawa in 2 weeks after a hot spell in Texas.

The kids call this density altitude changes, I just tell JBM what I'm getting into and it plots it out for me.

One last thing, get a little notebook that you will keep with the rifle. In it, you should have the drop sheet for your load or loads, the details of each load if you handload and the specs of your rifle, barrel, chamber, etc. I also have a drawing of my reticle with the subtensions defined. I also keep track of where I shoot, the settings on the scope for that venue and the conditions at that time. This way, I know where I left my scope dials the last time I shot. I don't always do that, but I try to keep it up to date.

2.5 scope height on the chart is suspect, check that. Buy a pic or scope mount level. It's a big deal further out.

quote:

Originally posted by offgrid:
2.5 scope height on the chart is suspect, check that. Buy a pic or scope mount level. It's a big deal further out.

That's too funny. It's the site height on my rifle, but then again, I have extra tall rings and a additional ramp. All by design, it's much more comfortable for me.

I read posts all the time from people looking to get the lowest rings possible to mount the scope virtually flush with the barrel. Horrible way to set up if spending any time behind a scope.

I'm not familiar with your scope, therefore I'm trying to determine how you will best use it.
- I believe this is a second focal plane scope. If so, this means that any markings on your reticle will be accurate -- on an angular basis across all magnifications and distances -- at only one magnification level. If your scope has a first focal plane reticle, any markings on your reticle will be accurate at all magnification levels.

- Assuming you have markings (technically called subtentions; some call them hash marks) on your reticle, do the subtentions have numbers that might be associated with MOA values? Or maybe the subtentions on the vertical portion of the reticle have numbers that might be associated with distances in yards?

- Does the scope have some type of "stop" at 0 for the elevation turret? This helps you get back to your zero elevation if you've been dialing elevation a lot. If you have a zero "stop" and you plan to engage it, I recommend changing your zero distance from 200 yards to 100 yards.

*****
A note on terminology. Technically, you have only 1 zero distance. If it's 200 yards, you dial elevation to obtain the intended impact at other distances -- say, 400 yards, as noted in your first post. According to your dope chart, you dial up 5.75 MOA to impact at 400 yards. This isn't "zeroing" at 400 yards, but only dialing in the proper elevation correction. Your "zero" stays at 200 yards in this example.

I can't tell from your scope/rifle photo, but a scope over bore height of 2.5" seems a little high, unless you have really tall rings. Most bolt actions will have a scope over bore height of around 1.75". Mine bolt action rifles were originally around 1.8". I recently went to taller rings, and my height is now 2.0". FYI, many AR15s have scope heights of 2.5". I recommend confirming the measurement from the center of your bore to the center of your scope.

*****
I'm not familiar with your ballistic program. I use JBM. Backing into the drop numbers as closely as I can, JBM has similar drops with density altitude of 4200'. Even with your temp of 85 F, DA of 4200' with absolute elevation of 500' is a big jump. I'm also not used to the air adjustment being applied to the ballistic coefficient -- at least that's what I think is going on. I believe you are using a Sierra Matchking 168.

For the SMK 168, G1 vs. G7 numbers generally aren't all that different for most ballistics programs. The bullet has been around for a long time, and most programs tweak the theoretical BCs for observed flight characteristics.

The SMK 168 bullet is very accurate at moderate distances, say 300 to 600 yards. Understand that the SMK 168 bullet starts to become unstable as its velocity approaches Mach 1.25 or possibly even 1.35. At your altitude, your bullet might fly quite accurately to maybe 700 yards, then maybe by 800 yards your accuracy takes a noticeable dump.

****
Don't count the number of clicks between desired elevation turret numbers. If you need 5.5 MOA, look at the dial and spin it to 5.5. If you next need to go to 8.75 MOA, look at the dial and spin it to 8.75.

****
Ultimately you must shoot at the various distances to determine if your theoretical ballistic program numbers are correct. Document any differences. Make certain your muzzle velocity is accurate.