I have read many topics around this and scanned the forums but have not found an answer so I have to ask. My question is if you have MOA turrets and a MIL reticle, would you still try to find out if your turrets are SMOA or TMOA? All the post I've read about SMOA and TMOA were only relating to MOA reticles and MOA turrets. Does it even matter since its a MIL reticle? All you Pros say everyone should check to see what they have. Im just confused would you still check if you had a MIL reticle. As always,I appreciate the help an understanding. thanks in advance guys.
Rifle Scopes Confusion on MOA turrets & MIL reticle?
- Thread starter mossievq
- Start date
Re: Confusion on MOA turrets & MIL reticle?
Sure.
With a .308, the difference in point of impact on a 1000 yard shot between IPHY adjustments and MOA adjustments is about 20 inches.
It's a good idea to know what you have.
Sure.
With a .308, the difference in point of impact on a 1000 yard shot between IPHY adjustments and MOA adjustments is about 20 inches.
It's a good idea to know what you have.
Re: Confusion on MOA turrets & MIL reticle?
At 1000 yards a typical 308 will have a correction of about 42 TMOA. The difference between SMOA and TMOA at that range and correction is almost 2 minutes (20" miss). It's good to know what your knobs do if you're shooting beyond 500 yds, otherwise it doesn't seem to make a lot of difference.
The best way is just take what you have out and shoot it, and make some notes. Most scopes aren't really EXACTLY true or shooter's MOA anyway, just shoot it and see where it hits, make notes and save the dope.
At 1000 yards a typical 308 will have a correction of about 42 TMOA. The difference between SMOA and TMOA at that range and correction is almost 2 minutes (20" miss). It's good to know what your knobs do if you're shooting beyond 500 yds, otherwise it doesn't seem to make a lot of difference.
The best way is just take what you have out and shoot it, and make some notes. Most scopes aren't really EXACTLY true or shooter's MOA anyway, just shoot it and see where it hits, make notes and save the dope.
Re: Confusion on MOA turrets & MIL reticle?
Shooting is not necessary.
Optically Checking Rifle Scopes
Shooting is not necessary.
Optically Checking Rifle Scopes
Re: Confusion on MOA turrets & MIL reticle?
I'll argue that shooting is the better way to get dope. It tells you what your rifle does, with your ammo, in real conditions.
Having the theory nailed down is great too, but if I could only have one range card I'll pick the one I made up at the range with the equipment I plan to shoot.
Thanks for the link, thats a cool way to check out your scope, especially if you have a surveyed range.
I'll argue that shooting is the better way to get dope. It tells you what your rifle does, with your ammo, in real conditions.
Having the theory nailed down is great too, but if I could only have one range card I'll pick the one I made up at the range with the equipment I plan to shoot.
Thanks for the link, thats a cool way to check out your scope, especially if you have a surveyed range.
Re: Confusion on MOA turrets & MIL reticle?
Forget you ever heard the term "Shooters Minute Of Angle" this is not a "Minute of Angle" it is "Inches Per Hundred Yards" (IPHY). There is only one "Minute Of Angle" (MOA) and it is 1/60 of 1 degree. And yes it is important to know which one you have as the others have stated
Forget you ever heard the term "Shooters Minute Of Angle" this is not a "Minute of Angle" it is "Inches Per Hundred Yards" (IPHY). There is only one "Minute Of Angle" (MOA) and it is 1/60 of 1 degree. And yes it is important to know which one you have as the others have stated
Re: Confusion on MOA turrets & MIL reticle?
Awesome! I thank all of you again for the help on this topic. In my sniper section we use all Leupold MK4 on our SR-25s so When I read the whole SMOA and TMOA I was intrested to know if it matter with the different turret and reticle calibration. I'll make sure we find out on the range this week with the info you guys have given me. Thanks again for being helpful guys.
Awesome! I thank all of you again for the help on this topic. In my sniper section we use all Leupold MK4 on our SR-25s so When I read the whole SMOA and TMOA I was intrested to know if it matter with the different turret and reticle calibration. I'll make sure we find out on the range this week with the info you guys have given me. Thanks again for being helpful guys.
Re: Confusion on MOA turrets & MIL reticle?
You don't need a range at all, for that, since you're not going to shoot, but you definitely need exactly a 100 yard length, measured with a tape - a laser rangefinder is not accurate enough.
If you're going to do it by shooting, what you want to do is to get a 4 foot high target up at 100 yards, with an aiming point near the bottom. Check your hundred yard zero on the aiming point.
Then crank on 36 MOA, and shoot another group <span style="font-style: italic">using the same aiming point.</span>
If the second group is 36 inches above the first one, the scope is calibrated in IPHY. If it's closer to 37.7 inches, the scope is calibrated in MOA.
Checking the calibration on a scope is a completely different exercise from getting dope.
Getting dope is great, but shooting at 1000 yards is neither the best way nor the easiest way to check the calibration of the scope - and a lot of people don't have access to long-distance ranges.
There are other things on a scope which can be checked without shooting. You should also check the calibration of the reticle, and, if the scope has a second focal-plane reticle, you should also check the calibration of the power ring. Neither of those can be checked by shooting, but are easy to check optically.
You don't need a range at all, for that, since you're not going to shoot, but you definitely need exactly a 100 yard length, measured with a tape - a laser rangefinder is not accurate enough.
If you're going to do it by shooting, what you want to do is to get a 4 foot high target up at 100 yards, with an aiming point near the bottom. Check your hundred yard zero on the aiming point.
Then crank on 36 MOA, and shoot another group <span style="font-style: italic">using the same aiming point.</span>
If the second group is 36 inches above the first one, the scope is calibrated in IPHY. If it's closer to 37.7 inches, the scope is calibrated in MOA.
Checking the calibration on a scope is a completely different exercise from getting dope.
Getting dope is great, but shooting at 1000 yards is neither the best way nor the easiest way to check the calibration of the scope - and a lot of people don't have access to long-distance ranges.
There are other things on a scope which can be checked without shooting. You should also check the calibration of the reticle, and, if the scope has a second focal-plane reticle, you should also check the calibration of the power ring. Neither of those can be checked by shooting, but are easy to check optically.
Re: Confusion on MOA turrets & MIL reticle?
Please excuse me if everyone here thinks Im asking a stupid question but hey Lindy, So how do you check the calibration on the power ring? and when you say check the reticle as well you mean an MOA reticle right cause a mil is a mil for the MIL reticle or would you still have to check?
Please excuse me if everyone here thinks Im asking a stupid question but hey Lindy, So how do you check the calibration on the power ring? and when you say check the reticle as well you mean an MOA reticle right cause a mil is a mil for the MIL reticle or would you still have to check?
Re: Confusion on MOA turrets & MIL reticle?
If you're talking about a reticle in the first focal plane, all you have to do is to ensure that the reticle subtends the correct amount. You need marks which you can clearly read at 100 yards. With an MOA reticle, at 100 yards, 40 MOA should subtend a distance of 41.88 inches.
The easiest way to check that is with 2 Shoot'N'C dots placed as nearly as possible exactly that amount apart from center to center, which I do on a 4 foot carpenter's ruler.
With a mil reticle, I place the dots exactly 36 inches apart, which is the distance that 10 mils should subtend at 100 yards.
Actually, I've never found a FFP reticle which was significantly off - but I check them anyway, because it's easy to do while I'm checking the adjustments.
A second focal plane reticle is another story altogether.
Check it as in the FFP reticle, but what you're checking first of all is that the power ring at which the manufacturer says the reticle is accurate for ranging is actually the power at which it is <span style="font-weight: bold">is</span> correct - and I have found scopes from a major manufacturer which could not be used correctly for ranging, because the power ring did not go to a high enough power for the reticle to be correct.
And while you are there, calibrate the half-power point, as I noted in my article, so that you can use the SFP reticle for moving targets leads, wind holds, holdovers, and holdunders at half power. That's handy for using the reticle in cases where the reticle is correct only at a power which is too high for convenient use, i.e., the field of view is too small.
If you're talking about a reticle in the first focal plane, all you have to do is to ensure that the reticle subtends the correct amount. You need marks which you can clearly read at 100 yards. With an MOA reticle, at 100 yards, 40 MOA should subtend a distance of 41.88 inches.
The easiest way to check that is with 2 Shoot'N'C dots placed as nearly as possible exactly that amount apart from center to center, which I do on a 4 foot carpenter's ruler.
With a mil reticle, I place the dots exactly 36 inches apart, which is the distance that 10 mils should subtend at 100 yards.
Actually, I've never found a FFP reticle which was significantly off - but I check them anyway, because it's easy to do while I'm checking the adjustments.
A second focal plane reticle is another story altogether.
Check it as in the FFP reticle, but what you're checking first of all is that the power ring at which the manufacturer says the reticle is accurate for ranging is actually the power at which it is <span style="font-weight: bold">is</span> correct - and I have found scopes from a major manufacturer which could not be used correctly for ranging, because the power ring did not go to a high enough power for the reticle to be correct.
And while you are there, calibrate the half-power point, as I noted in my article, so that you can use the SFP reticle for moving targets leads, wind holds, holdovers, and holdunders at half power. That's handy for using the reticle in cases where the reticle is correct only at a power which is too high for convenient use, i.e., the field of view is too small.
Re: Confusion on MOA turrets & MIL reticle?
PLEASE check your scope if you plan on ranging. I just finished up LE Sniper school and I set up the grid for the other officers to check their scopes. Of 17 optics checked 12 failed to subtend correctly against the hard stop, 3 were able to be dialed down to correct subtention. That left 9 of 17 that will not range correctly w/o doing a bunch of math to figure out what the correct multiplier is. There is a single company that will be receiving a bunch of optics from various LE agencies in the near future to correct this.
Cheers,
Doc
PLEASE check your scope if you plan on ranging. I just finished up LE Sniper school and I set up the grid for the other officers to check their scopes. Of 17 optics checked 12 failed to subtend correctly against the hard stop, 3 were able to be dialed down to correct subtention. That left 9 of 17 that will not range correctly w/o doing a bunch of math to figure out what the correct multiplier is. There is a single company that will be receiving a bunch of optics from various LE agencies in the near future to correct this.
Cheers,
Doc
Re: Confusion on MOA turrets & MIL reticle?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: doc76251</div><div class="ubbcode-body">PLEASE check your scope if you plan on ranging. I just finished up LE Sniper school and I set up the grid for the other officers to check their scopes. Of 17 optics checked 12 failed to subtend correctly against the hard stop, 3 were able to be dialed down to correct subtention. That left 9 of 17 that will not range correctly w/o doing a bunch of math to figure out what the correct multiplier is. There is a single company that will be receiving a bunch of optics from various LE agencies in the near future to correct this.
Cheers,
Doc </div></div>
Would that company's name just happen to start with an "L"? I really hope the name isn't also known as "NF", "USO", "S&B, or "PR". I just want to save myself a lot of future heart ache when I buy my next scope.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: doc76251</div><div class="ubbcode-body">PLEASE check your scope if you plan on ranging. I just finished up LE Sniper school and I set up the grid for the other officers to check their scopes. Of 17 optics checked 12 failed to subtend correctly against the hard stop, 3 were able to be dialed down to correct subtention. That left 9 of 17 that will not range correctly w/o doing a bunch of math to figure out what the correct multiplier is. There is a single company that will be receiving a bunch of optics from various LE agencies in the near future to correct this.
Cheers,
Doc </div></div>
Would that company's name just happen to start with an "L"? I really hope the name isn't also known as "NF", "USO", "S&B, or "PR". I just want to save myself a lot of future heart ache when I buy my next scope.
Re: Confusion on MOA turrets & MIL reticle?
I have never been one to throw another company under the bus on a short survey such as the above. What I will say is that if you have a scope, by any manufacturer, it would serve you well to check not only the subtention of your reticle but also the value of your "clicks". It is a simple procedure and is IMPERATIVE to achieve optimum accuracy not only for ranging but for use of a ballistic chart. As Lindy and many other opine the result of a .047 error results in a 20" miss at 1K. I have witnessed errors significantly larger than that in several different scope platforms.
R.R said "Trust but Verify"
Doc says "Check your sh!t!"
Cheers,
Doc
I have never been one to throw another company under the bus on a short survey such as the above. What I will say is that if you have a scope, by any manufacturer, it would serve you well to check not only the subtention of your reticle but also the value of your "clicks". It is a simple procedure and is IMPERATIVE to achieve optimum accuracy not only for ranging but for use of a ballistic chart. As Lindy and many other opine the result of a .047 error results in a 20" miss at 1K. I have witnessed errors significantly larger than that in several different scope platforms.
R.R said "Trust but Verify"
Doc says "Check your sh!t!"
Cheers,
Doc
Re: Confusion on MOA turrets & MIL reticle?
For what it's worth, I was chatting recently with a representative of a major scope manufacturer, whose claim was that the industry standard for scope adjustment accuracy was 2 percent.
It's useful to note how an error of a given magnitude translates into elevation errors. Take the drop of your load, in inches, at a given distance. Multiply that figure by the error rate, and that's how big the potential error is.
For example, assume that my .308 drops 415 inches at 1000 yards. Two percent of that is 8.3 inches.
I check my scopes. I encourage others to do likewise.
For what it's worth, I was chatting recently with a representative of a major scope manufacturer, whose claim was that the industry standard for scope adjustment accuracy was 2 percent.
It's useful to note how an error of a given magnitude translates into elevation errors. Take the drop of your load, in inches, at a given distance. Multiply that figure by the error rate, and that's how big the potential error is.
For example, assume that my .308 drops 415 inches at 1000 yards. Two percent of that is 8.3 inches.
I check my scopes. I encourage others to do likewise.
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