I mainly follow the reloading forum, and only have experience posting from there, so I’m not sure how to post in a different forum yet. Regardless, this post is all about figuring out Scope Turret dial up in MOA and Mils, when you already know the bullet drop in inches based off a trajectory data at given distances. I suppose it’s all relative, as it applies to reloading, since we often use optics to shoot for groups at distance.
Anyhow, I was at the range recently when a shooter (who only had a box of factory ammo with published trajectory drop data) asked me how he was supposed to know how many MOAs to dial up for a 500yd shot, based off his ammo box’s drop data? I explained it all to him, and although it’s probably been covered plenty of times on the hide, I figured I would share what I told him for the benefit of the newcomers to the sport. Unfortunately it involves math, so if you’re still reading, pls don’t bail yet. It’s not all that bad.
Well, this is a two step process for both MOA and Mils that goes as follows:
Step 1- For MOA, you must first figure out what 1 MOA equals at the DISTANCE you are shooting.
*MOA is defined as, “Minute of Angle”, meaning it’s a linear angle, which increases in value the further away from the muzzle that distance gets. An MOAs baseline value is defined as 1.047 inches at 100yds; therefore, to determine what 1 MOA equals at a distance FURTHER than 100yds, you must first apply the following formula:
(Distance to target in Yards / 100) X 1.047= 1 MOA at that given distance.
Ex: If Target Distance is 573yds.
(573 / 100) X 1.047=
(5.73) X 1.047= 5.99931in
So, 1 MOA at 573yds= 5.99931 inches.
Step 2-Divide the known elevation drop in inches at that given distance by the value of what 1 MOA equals AT THAT given distance.
Ex: To continue with the same example of 573yds used in Step 1, let’s pretend your trajectory chart says the bullet drop for your ammunition at 573yds will be 66 inches.
What to dial in the Scope Turret = (Drop in Inches at a given distance) divided by (1 MOA’s value at that given distance)
66 (drop in inches at 573yds) / 5.99931 (what 1 MOA equals at 573yds) = 11.001 MOAs
So, if your bullet’s trajectory chart stated the bullet will drop 66 inches at 573 yards, you would need to dial up 11 MOAs in your MOA scope turret to be on target at that 573yd distance.
**Note: If you have a Milrad Scope, the principal is EXACTLY the same, but there is one thing that will change in the formula, which is the baseline value of a Mil versus an MOA. The baseline value of 1Mil is defined as 3.6 inches at 100yds.
For a Milrad Scope, if we use the same example of 573yds with a 66 inch drop:
Step1-
(573 / 100) X 3.6 = 20.628
So, 1 Mil at 573yds = 20.628 inches
Step2-
66in drop / 20.628in = 3.199mils
So, if your bullet’s trajectory chart stated your bullet will drop 66 inches at 573yds, AND you have a Milrad scope, you would have to dial up 3.2mils in your Scope’s turret to be on target at that 573 yard distance.
Other helpful applications that can be determined by knowing what the value of 1 MOA is at a given distance beyond 100yds is trying to determine group size in MOA beyond 100yds.
Using the same example of 573yds, let’s say you shot a 5-Shot group with your rifle at 573yds, and then you measured the group with calipers and found it to be 4.130 inches. What would your group size be in MOA?
Since we already determined earlier the value of 1 MOA at 573yds equals 5.99931 inches, half your work is already done.
Simply divide your group size in inches at that distance by the value of 1MOA at that given distance.
Ex: 4.130inch (group size in inches) / 5.99931 (value of 1MOA at 573yds) = 0.688 MOA group.
Personal Observations and Opinions of MOA versus Milrad:
Because the baseline 100yd values of MOA (1.047”) versus Mils (3.6”) are vastly different, you can clearly see the MOA system has a much finer resolution than Milrad, which can allow for slightly finer adjustment increments than Milrad; however, along with that finer resolution, for practical real world applications, you can also clearly see one drawback to MOA is that MOA requires way more turning of the turret dial at distance to achieve the same elevation offset you could achieve using significantly less dialing with a Milrad platform. You essentially have to turn an MOA Turret 3 times more than a Milrad Turret to achieve the same elevation offset. IMO, this drawback makes it more difficult to keep track of how many clicks you’ve encompassed once you go beyond a full revolution in the turret. For practical shooting distances of 1000yds and in, with most typical large bore centerfire calibers greater than .22, I’ve found it’s rare that I need to adjust a Milrad Turret more than one complete full revolution, whereas on most MOA Turrets, depending on the Turret’s size and how many MOAs are encompassed in one complete revolution, you might need to turn your MOA Turret as little as 1.0 to 1.5 full revolutions, to as many as 2.5 to 3.0 full revolutions to be on target at 1000yds, whereas most Milrad scopes will get you there in 1 revolution or less. When you have to turn an MOA Turret more than one revolution, it becomes more difficult to keep track of where you are, as well as distracting when having to keep track of and perform mental math under stressful shooting conditions when one revolution of your MOA turret ends at 24 MOA, so when the 0 comes back up, now it’s representing 25 MOA, but you need to dial up a total of 38MOA to be on at 1000, lol. Things get sticky quick. These factors make it super easy to lose track of your adjustments, and you could find yourself off by one or more MOAs when adjusting, which can mean the difference between an impact and a miss at distance depending on your target size.
I’m not saying there is anything wrong with the MOA system, it just boils down to personal preference. I started out using MOA Turrets, and I still have them on some of my platforms, but once I got into longer range shooting, and after I flubbed my dial up on way more than a few occasions due to miscalculation or getting lost in my clicks, I began contemplating the benefits of Milrad. It took a good bit of research, and even more convincing knowing I was going have to learn new math based of 3.6 inches, but I eventually did try a Milrad Scope, and I liked it so much more, that I vowed I would never go back to MOA as far as new purchases are concerned.
Was all of this post necessary? No, absolutely not. There are tons of ballistic calculators out there that will do all the math for you, BUT if you’re a new shooter and you don’t have a ballistics app yet, or maybe no chronograph either, or maybe you’re a seasoned shooter and your electronics died, and all you have with you is a store bought box of ammunition with published velocity and bullet drop data listed on the box, knowing how to do the math is crucial to knowing how to dial your turret for distances covered by the drop data. The ONLY other way to know how to dial the turret would be guessing, then adjusting DOPE as required as you burn through ammo walking your impacts onto target. The published velocity and trajectory drops on the box of ammo will likely NOT match what your barrel/chamber will produce. That is because the published data was obtained with a different chamber and test barrel than your barrel, and oftentimes using a barrel that will likely be longer than your barrel producing velocities higher than what your barrel will produce resulting in flatter trajectory than your barrel, so what you see on target with regard to velocity and bullet drop will likely be off somewhat from what the box of ammunition states it should be. Shooting the ammunition at the distances where the manufacturer provided published data, then measuring the differences in actual drop on target versus what the box says, then knowing how to do the math yourself, will also allow you be close enough to extrapolate the dial up for those in-between published data distances.
My apologies for how long this was. I run into new shooters all the time and I’m often asked questions about MOA & Milrad, so figured I would do my best to try to explain what little I know about it in hopes that it can help newcomers to the sport, as well as be a refresher to those who have become reliant on ballistic apps to the point where they may’ve gotten rusty on the math. Hope this was helpful!
Anyhow, I was at the range recently when a shooter (who only had a box of factory ammo with published trajectory drop data) asked me how he was supposed to know how many MOAs to dial up for a 500yd shot, based off his ammo box’s drop data? I explained it all to him, and although it’s probably been covered plenty of times on the hide, I figured I would share what I told him for the benefit of the newcomers to the sport. Unfortunately it involves math, so if you’re still reading, pls don’t bail yet. It’s not all that bad.
Well, this is a two step process for both MOA and Mils that goes as follows:
Step 1- For MOA, you must first figure out what 1 MOA equals at the DISTANCE you are shooting.
*MOA is defined as, “Minute of Angle”, meaning it’s a linear angle, which increases in value the further away from the muzzle that distance gets. An MOAs baseline value is defined as 1.047 inches at 100yds; therefore, to determine what 1 MOA equals at a distance FURTHER than 100yds, you must first apply the following formula:
(Distance to target in Yards / 100) X 1.047= 1 MOA at that given distance.
Ex: If Target Distance is 573yds.
(573 / 100) X 1.047=
(5.73) X 1.047= 5.99931in
So, 1 MOA at 573yds= 5.99931 inches.
Step 2-Divide the known elevation drop in inches at that given distance by the value of what 1 MOA equals AT THAT given distance.
Ex: To continue with the same example of 573yds used in Step 1, let’s pretend your trajectory chart says the bullet drop for your ammunition at 573yds will be 66 inches.
What to dial in the Scope Turret = (Drop in Inches at a given distance) divided by (1 MOA’s value at that given distance)
66 (drop in inches at 573yds) / 5.99931 (what 1 MOA equals at 573yds) = 11.001 MOAs
So, if your bullet’s trajectory chart stated the bullet will drop 66 inches at 573 yards, you would need to dial up 11 MOAs in your MOA scope turret to be on target at that 573yd distance.
**Note: If you have a Milrad Scope, the principal is EXACTLY the same, but there is one thing that will change in the formula, which is the baseline value of a Mil versus an MOA. The baseline value of 1Mil is defined as 3.6 inches at 100yds.
For a Milrad Scope, if we use the same example of 573yds with a 66 inch drop:
Step1-
(573 / 100) X 3.6 = 20.628
So, 1 Mil at 573yds = 20.628 inches
Step2-
66in drop / 20.628in = 3.199mils
So, if your bullet’s trajectory chart stated your bullet will drop 66 inches at 573yds, AND you have a Milrad scope, you would have to dial up 3.2mils in your Scope’s turret to be on target at that 573 yard distance.
Other helpful applications that can be determined by knowing what the value of 1 MOA is at a given distance beyond 100yds is trying to determine group size in MOA beyond 100yds.
Using the same example of 573yds, let’s say you shot a 5-Shot group with your rifle at 573yds, and then you measured the group with calipers and found it to be 4.130 inches. What would your group size be in MOA?
Since we already determined earlier the value of 1 MOA at 573yds equals 5.99931 inches, half your work is already done.
Simply divide your group size in inches at that distance by the value of 1MOA at that given distance.
Ex: 4.130inch (group size in inches) / 5.99931 (value of 1MOA at 573yds) = 0.688 MOA group.
Personal Observations and Opinions of MOA versus Milrad:
Because the baseline 100yd values of MOA (1.047”) versus Mils (3.6”) are vastly different, you can clearly see the MOA system has a much finer resolution than Milrad, which can allow for slightly finer adjustment increments than Milrad; however, along with that finer resolution, for practical real world applications, you can also clearly see one drawback to MOA is that MOA requires way more turning of the turret dial at distance to achieve the same elevation offset you could achieve using significantly less dialing with a Milrad platform. You essentially have to turn an MOA Turret 3 times more than a Milrad Turret to achieve the same elevation offset. IMO, this drawback makes it more difficult to keep track of how many clicks you’ve encompassed once you go beyond a full revolution in the turret. For practical shooting distances of 1000yds and in, with most typical large bore centerfire calibers greater than .22, I’ve found it’s rare that I need to adjust a Milrad Turret more than one complete full revolution, whereas on most MOA Turrets, depending on the Turret’s size and how many MOAs are encompassed in one complete revolution, you might need to turn your MOA Turret as little as 1.0 to 1.5 full revolutions, to as many as 2.5 to 3.0 full revolutions to be on target at 1000yds, whereas most Milrad scopes will get you there in 1 revolution or less. When you have to turn an MOA Turret more than one revolution, it becomes more difficult to keep track of where you are, as well as distracting when having to keep track of and perform mental math under stressful shooting conditions when one revolution of your MOA turret ends at 24 MOA, so when the 0 comes back up, now it’s representing 25 MOA, but you need to dial up a total of 38MOA to be on at 1000, lol. Things get sticky quick. These factors make it super easy to lose track of your adjustments, and you could find yourself off by one or more MOAs when adjusting, which can mean the difference between an impact and a miss at distance depending on your target size.
I’m not saying there is anything wrong with the MOA system, it just boils down to personal preference. I started out using MOA Turrets, and I still have them on some of my platforms, but once I got into longer range shooting, and after I flubbed my dial up on way more than a few occasions due to miscalculation or getting lost in my clicks, I began contemplating the benefits of Milrad. It took a good bit of research, and even more convincing knowing I was going have to learn new math based of 3.6 inches, but I eventually did try a Milrad Scope, and I liked it so much more, that I vowed I would never go back to MOA as far as new purchases are concerned.
Was all of this post necessary? No, absolutely not. There are tons of ballistic calculators out there that will do all the math for you, BUT if you’re a new shooter and you don’t have a ballistics app yet, or maybe no chronograph either, or maybe you’re a seasoned shooter and your electronics died, and all you have with you is a store bought box of ammunition with published velocity and bullet drop data listed on the box, knowing how to do the math is crucial to knowing how to dial your turret for distances covered by the drop data. The ONLY other way to know how to dial the turret would be guessing, then adjusting DOPE as required as you burn through ammo walking your impacts onto target. The published velocity and trajectory drops on the box of ammo will likely NOT match what your barrel/chamber will produce. That is because the published data was obtained with a different chamber and test barrel than your barrel, and oftentimes using a barrel that will likely be longer than your barrel producing velocities higher than what your barrel will produce resulting in flatter trajectory than your barrel, so what you see on target with regard to velocity and bullet drop will likely be off somewhat from what the box of ammunition states it should be. Shooting the ammunition at the distances where the manufacturer provided published data, then measuring the differences in actual drop on target versus what the box says, then knowing how to do the math yourself, will also allow you be close enough to extrapolate the dial up for those in-between published data distances.
My apologies for how long this was. I run into new shooters all the time and I’m often asked questions about MOA & Milrad, so figured I would do my best to try to explain what little I know about it in hopes that it can help newcomers to the sport, as well as be a refresher to those who have become reliant on ballistic apps to the point where they may’ve gotten rusty on the math. Hope this was helpful!
