MRAD vs MOA

[LoonWulf]

I would not make a statement about the group as some dial, some hold over.... the only certainty is the guy that does it differently will chime in... do what works for you....

Agreed, but again if your all working in the same system it wouldnt really matter, at least in my mind.
Kind of do that at work. I prefer to think in micromoles, and do all of my calculations that way.
My wife thinks a milligrams per liter, and it's her lab, so I switched to using milligrams per liter.

Didnt think about it till now, but my dad generally works in plates for his shooting and measuring....weve gone over moa/mil but even tho his scope has a graduated reticle, hes going to revert to working in plates after making the initial vertical adjustment, which ill give him in MOA (his scope is MOA). So with him it's just easier to work within his system and make all the calls in plates.

 

[Varminterror]

Computers, tools, calculators are all nice. But I'm the kind of guy that needs to know where the numbers come from. Some competitions allow tools others don't. So I like to be ready to do it on my own

At the risk of sounding curt, it's simple fallacy to believe if you don't have a ballistic calculator that you'll do the math "longhand." You won't, and frankly DAMNED SURE can't do so expediently in the field or during a match, even if you do have the skills and understanding the physics and differential calculus to do so. Honestly, I'd bet heavily against more than one or two other folks commenting in this thread having ever calculating trajectory longhand, or even in software like matlab or Excel.

Plainly, guys aren't talking about calculating trajectory longhand, they're talking about using a crude measurement tool which is only useful for delivering approximate fire on large targets at what are still short ranges.

Here's the rub: you need two numbers to deliver shots on target downrange - you need the vertical "elevation" correction corresponding to the range you're shooting (compounded by the wind influence on vertical displacement) and you need the horizontal "windage" correction required to compensate for the wind in which you're shooting (compounded by spin drift over distance you're shooting). But you'll never do that "math" which actually yields those numbers. It's an absolute waste of time for any shooter to independently develop the math skills and then calculate drop based on a differential velocity model, let alone a differential drag model (AB CDM's, Hornady 4DoF profiles). When we don't have access to ballistic calculators (and many of us have been shooting LR since before we had calculators), we still don't calculate trajectory longhand, we either 1) look up trajectories based on ballistic tables or 2) shoot multiple ranges in the field, walking shots onto target and recording corresponding corrections to establish our own DOPE books - Data On Previous Engagements. I spent countless hours in the back of the Speer 13th manual in the late 1990's and early 2000's reading ballistic tables, plotting that onto graph paper to interpolate smaller increments, and extrapolating longer distances as a starting point for going to the range and developing my own longer range data tables (DOPE books). Nobody is doing any "math" to solve for trajectory.

So all of the "math" guys talk about in this discussion really is just novelty stuff, like gross range estimation, after which they still have to go back to a DOPE book or other data table, or ballistic calculator to determine the two numbers we're actually using. It's cute to talk about using known or estimated target sizes to estimate distances, and if you're shooting huge targets at short distances, sure, it works well enough - but it's not long range shooting, and it's not pertinent for PRS competition. Sure, if you just need to put a bullet anywhere on a man-sized target at 400-600yards it's useful, but for actual long range shooting and trying to hold onto reasonably sized targets (not billboards), mil-ranging just isn't useful. Here's an example: Picking a reasonably sized target I shoot relatively often, let's say I KNOW a target is exactly 12" and I read 0.3mils - that's 1112yrds... But wait... maybe it was 0.35mils (meaning my error lining up the target in the reticle hashes was literally the width of the lines in my scope), 12" subtending 0.35mils is only 953yrds, so 159yrds worth of ranging error, which for my 300win mag load, that's 8.9 FEET of error, all because I couldn't discern whether a 12" target at nearly 1000yrds was spreading between the centers of two lines, or the outside edges... Missing a target by almost 9 times its own size... That's not really math I would consider pertinent for any kind of Long Range shooting I have ever done...

VERY SPECIFICALLY TO PRS COMPETITION: You'll be provided ranges at PRS matches and you'll be allowed to use a laser rangefinder if you ever think the ranges provided in the match book are incorrect. Nobody on any squad at any match I've ever shot would want to stand around and waste time waiting for a shooter to mil-range targets, and most matches don't provide sizes for all of targets, many don't provide sizes for ANY of the targets. There USED TO BE matches occasionally which would include a "blind stage" or a "milling stage" where guys had to either range with the LRF and determine trajectory on the clock, usually 5min stages instead of 90/105/120 sec, or where guys had to mil-targets to determine the range, but again, these were huge targets, and guys used their phones to read the mils in the scope, calculate target inches / mils read * 27.8, then put that number into their ballistic engine. At WORST, throw a trajectory data table on your wrist coach, and that ONE formula will give you all of the info you'll ever need - or rather NEVER need, because we don't do that at PRS matches. Know 1 formula in case you get stuck with a mil-ranging stage - which I haven't heard of happening in at least 3years at a regional series match, and I have NEVER heard of one at a pro series match in the 7yrs I've been shooting PRS.

Maybe I should have been more clear about these REASONS this math is a waste of time in my first post instead of simply pointing out that it's a waste of time... It's not worthwhile to do the worthwhile math longhand, and the math being described above for mil-ranging is not worthwhile math for long range shooting, especially not for PRS shooting.

 

[Varminterror]

I know or have met/been on squad around the country with hundreds of PRS shooters:

1) I have NEVER met a successful/competitive shooter, or any shooter which competes with any regularity, which holds elevation for every stage. Yes, there are a few newbies which come in with the wrong class of scope or under-practiced, so they hold range, and they get torn up badly. And yes, we all have to know how to hold AND dial, because we may be forced by stage rules, or driven by stage design to hold instead of dial, but these are typically only one or two stages per match where this comes up, either as requirement or strategic choice.

2) Yes, some shooters NEVER dial wind, some do dial wind. I do both, just depends on the match and the range at which we're shooting.

3) I have never met a PRS shooter which uses KPH for windspeed. I'm sure some of the EU guys use KPH, but we generally don't recommend replicating what those ~100 dudes are doing over what the ~6000 dudes in the US are doing unless you live and compete in the EU.

 

[Nature Boy]

In BR we are not allowed to have any electronic devices at our bench during a record string, nor are we allowed to have a spotter beyond the live pits or coach talking during a record string. No inputting of data etc. I also can’t name one LRBR competitor that uses Mil based scopes but in all fairness I’ve haven’t polled either but as pointed out earlier that when sharing data it’s nice to be on the same wavelength.

There’s a reason why MOA is preferable in precision shooting sports like BR and F Class. They often require finer adjustments than allowed with a 0.1 mil scope.

 

[Varminterror]

In BR we are not allowed to have any electronic devices at our bench during a record string

In fairness, it's not terribly pertinent in BR to have a calculator at hand - it's all fixed, known distance shooting. How many BR formats even shoot at multiple distances during a single string? How many BR formats don't have sighting periods or allow sighters within the string at the distance being fired? How far apart during the day will one string be fired compared to the next, and are sighters not allowed before each string?

AND in fairness, PRS shooters don't have their ballistic solvers or LRF's on the line either. We have 90, 105, or 120 seconds to shoot 10 shots, all of the data prep is done between stages, written on data cards, and carried to the line. All of our solutions are either on our rifle or on our arm while we're firing for score. We might shoot 60+ distances during a match, and there are NO sighters for any distance during the match, so there's no opportunity to refine elevation corrections as the environmental conditions change through a day.

It's just a different format. When I was shooting service rifle, I knew the "clicks" for my sight at the 3 pertinent distances - we shot them every match. Some matches might have lower or higher Density Altitude, or brighter light vs. cloudy skies, so I might shift a click or two here or there, but by and large, there wasn't a need for any calculation. Different tools for different tasks - I can't live that way in PRS competition.

 

[Nature Boy]

I can't live that way in PRS competition.

I can imagine what a slow and frustrating process it would be spinning through 1/8 MOA increments in a timed field event.

 

[Varminterror]

I can imagine what a slow and frustrating process it would be spinning through 1/8 MOA increments in a timed field event.

That too!

I have "known" 1/8moa scopes are slower, even 1/4moa scopes are slower, than 0.1mil scopes, but until just now, I hadn't done the work to understand how much slower: Most 1/8moa turrets only have 10moa per revolution, meaning the AVERAGE shot at any PRS match would be ~1.5 revs, whereas on a common 0.1mil turret, it would only be 1/3-1/2 turn of the turret. Definitely slower, and WAY easier to get lost. With my Bushnell DMR II, I had 10 mils per revolution, so I could pass 1300yrds without "revving up," so it was almost impossible to get lost (I'd guess I've only shot ~20 total shots past 1300yrds at PRS matches in 7yrs). Even with my slower Dasher, I get past 1100yrds before finishing a rev. That would be THREE Revs in a 1/8moa scope... On my Kahles, I have 15mils per rev, so I have to go clear out past 1400yrds before I turn past my first rev, which is using ~1/2 of the total adjustment my scope offers, whereas most 1/8moa scopes seem to have ~45-55moa available (if using an angled base), so some 1/8moa scopes would run out of total adjustment before I even turned my turret once, and the 1/8moa scope would REQUIRE a perfectly designed 22.5-27.5moa base, and most 0.1mil scope can do it on a flat base...

Tools for tasks. When I dial ONE click at 1000 in my NF ATACR, my impact moves 3.6", whereas when SPJ dials ONE click in his NF Competition, his bullet only moves 1.3", so if my group isn't scoring well, I'd have to nudge my hold over, whereas he can dial and hold center. I can "dial a mile" from a 100yrd zero on mine, and his can't. Tools for tasks. Razor blades aren't made for splitting wood, and axes aren't made for shaping beards.

 

[JFrank]

There’s a reason why MOA is preferable in precision shooting sports like BR and F Class. They often require finer adjustments than allowed with a 0.1 mil scope.

Which do you prefer for F class ?

 

[LoonWulf]

Razor blades aren't made for splitting wood, and axes aren't made for shaping beards.

There's a joke to make right there.....I known there is.....but all I get is the Brawny guy.....

 

[Nature Boy]

Which do you prefer for F class ?

MOA

I’ve used MIL before but often find my POI is in between clicks

I have "known" 1/8moa scopes are slower, even 1/4moa scopes are slower, than 0.1mil scopes, but until just now, I hadn't done the work to understand how much slower: Most 1/8moa turrets only have 10moa per revolution, meaning the AVERAGE shot at any PRS match would be ~1.5 revs, whereas on a common 0.1mil turret, it would only be 1/3-1/2 turn of the turret. Definitely slower, and WAY easier to get lost.

You can see what you’re talking about by looking at them side by side

My Kahles 1050 1/8 MOA on left and Kahles 624 0.1 MIL on the right

 

[JFrank]

I would not make a statement about the group as some dial, some hold over.... the only certainty is the guy that does it differently will chime in... do what works for you....

To be honest, I tend to get a decent zero for the day and mainly hold over or get risk getting lost when a change of wind direction pops up, which in my experience wreaks more havoc than wind speed.

 

[Nature Boy]

Same Jim. I dial for elevation then hold for wind….mostly.

 

[JFrank]

@Nature Boy
Those are really nice scopes.

 

[AJC1]

Same Jim. I dial for elevation then hold for wind….mostly.

That's what I do as well, but I shoot way more steel Silhouette which is more like br.

 

[Walkalong]

All I'm saying is wind calls are almost always in mph so unless your wind calls are in kph your still faking it.

MPH works with either MOA or Mils, so I don't see your point, and again, without math, we know what say 5MPH does to our bullet at X yardage because the ballistics program tells us, but again, no need to convert anything.

 

[Walkalong]

The way i see it....Wind calls could be in KPH, vertical could be in Mils, horizontal could be in MOA.
As long as you're working within those systems and not trying to use one for the other, you really don't have to do any math.

Correct

 

[Walkalong]

You can see what you’re talking about by looking at them side by side

My Kahles 1050 1/8 MOA on left and Kahles 624 0.1 MIL on the right

Exactly what I mean when I say MRAD deals with smaller numbers, which I like.

I stole @Nature Boy's pic and modded it.

 

[jmorris]

Smaller numbers and actually more intuitive. I am an older guy and set in my (more difficult) ways often but I took to Mrad like a duck to water. It didn’t seem difficult but I only looked at it from a data/input perspective not a conversion one.

 

[ExtremeSquared]

Right I would to but those countries us metric.... and the debate is about conversion, and I don't see usa prs shooters making wind calls in kph.

Milliradians aren't metric units. They are dimensionless angular units. Kph/mph wind velocity is 100% irrelevant to any angular unit.

 

[Varminterror]

Milliradians aren't metric units.

Unfortunately, this flies around the internet, but Radians ARE adopted within the International System of Units, aka 'metric system.' It's "dimensionless", but it remains a unit of measure within the Metric System. I'll never understand why so many folks insist "Radians aren't metric," but they are. I assume it has something to do with an outdated perception that the US military wouldn't use metric units, because we're Americans, by God... But Radians are metric.

 

[IndianaBoy]

I use mils for PRS shooting, because it's simple and everyone else is speaking the same language.

I use a good BDC based reticle for 3 gun.

I've never played benchrest of F-class sports so I can't speak to that equipment, but it seems that MOA is the rule of the day.

2 sides of the same coin. My Kestrel with Applied Ballistics software will generate whichever data set I prefer.

 

[Nature Boy]

1 centimeter is the same as 1 MIL

I actually didn’t realize this this until @taliv pointed it out to me in this thread. Felt pretty stupid about it too

https://www.thehighroad.org/index.php?threads/first-impression-swarovski-z6i.844155/

I assume it has something to do with an outdated perception that the US military wouldn't use metric units, because we're Americans, by God...

Fun fact, the Army and the Marines have been using the metric system of measure since 1957

 

[Carl N. Brown]

Sneezly the Seal said "Arc! Arc! Arc!".

 

[Chief TC]

I am a BPCR and milsurp shooter mostly, so MOA is what makes sense for me, especially since that is how vernier sights and milsurp sights are designed. I only shoot scoped for hunting and MOA still works perfect for my uses. However, being military and the intent of PRS, mils is the way to go. Use and learn what you need to accomplish your goals.

 

[mcb]

Radians are really an angular measurement that is independent of the measurement system. They come primarily out of mathematics, the unit circle and the definition of the fundamental trigonometry functions. One radian is defined as the angle subtended from the center of a circle which intercepts an arc equal in length to the radius of the circle. Defining the radians as the ratio of arc length over radius means radians are unitless and are useful and perfectly acceptable in SI (Metric) or US Customary or nearly any other measurement system we might use.