Home Forums Hunting & Shooting Hunting Optics How to use that new SWFA scope- reticle, turrets and proper usage.

I have gotten a bunch of requests to write up a "how to" for the SWFA Milquad reticle. It is the 6x42mm SS with MQ reticle in the pictures, however the process and use is the same as long as you have a scope who's reticle matches the turret adjustments- mil/mil or MOA/MOA. Mil/mil has some advantages, but the system works regardless.



The set up-



Tikka T3 SL in 223
SWFA SS 6x42mm MQ
Pic base and rings
Blackhills 5.56mm 77gr SMKs


Also a Leupold Mark4 12-40x60mm spotter with H32 reticle. This is not necessary but really helpful.


The target after bore sighting. Dot is 1.5". Target is at 100 yards.


Understand that the reticle is broken down into .5 mils. Every tick mark is .5 mil, with a bigger tick at each whole mil. The turret adjusts in .1 mil increments. Don't get freaked out by mils- it's just a measuring tape. We will not be thinking in inches at all and instead will use the reticle as a ruler.

Then because it's a known rifle I fire one round. If it were a new or unknown rifle I would go ahead and get a ten (10) round group out as long as it's on paper.

First round.





It's easy to see through the scope, but it doesn't show when taking a picture through it so I placed a 1/2" dot over the hole so it shows up.



Now place the reticle back on the target and "read" the ruler.



It's literally telling you what to adjust. Just break the reticle down visually into tenths.

In this case- "down 1.7 and right 1.5" mils.



If you move the reticle up and bisect the bullet hole and aiming point like this it's even easier to see-

The easiest is to have a spotter with a mil reticle in it.




So you adjust "down 1.7 and right 1.5" mils. Fire another shot-


Closer look-

Now fire nine more to confirm-









From the reticle and target, dial- left .1mil to center the group. Loosen turret screws, lift off, spin and align with the "0" indicator mark.





Zeroing is done. No mental gymnastics, no fuss, no conversions, no weirdness. Think only in mils. Break it down into tenths visually and do not try to convert it to something else. See where the impact is with the reticle, adjust what it says, and done. Firing a statistically significant amount of rounds to see the true center of the group is important as you can easily be off .2 mil with a "1 moa all day" long rifle if you "zero" off of 3 shot groups.

Now how do you take a zeroed rifle and use those turrets and that reticle?



You need a dope card or drop card that tells you how much to adjust for a given range.

We used to have to hang targets at every 100 yard line and walk our rounds into the target, note the required adjustments, and move to the next. With the advent of accurate ballistic solvers you no longer need to do that. You can use the ballistic program to "true" your data. If you know the real BC of the bullet you can true the velocity, or if you know the real muzzle velocity you can true the BC for an unknown bullet. In general chronographs are the weakest link and I would default to velocity calibration.

It's pretty easy to find accurate BC's for most bullets by selecting the bullets with "Litz" next to them in the ballistic program as those have been tested and verified by Applied Ballistics and Bryan Litz. While it is improving, manufacturers love to inflate their BC numbers.


The best way to true is to shoot a target as close to transonic speed as possible- as close to 1,340fps as you can. If you can't get that far, then do it as far as possible. If you input all the variables correctly scope height, BC, range, weather, etc. the outcome will be VERY accurate data out to the range that you trued.

For a target I use a piece of steel with a waterline across the middle (this one is set at 600). The goal is to get your rounds splitting the line. This allows you to true your velocity by manipulating the app.






You need a good app. There are quite a few good ones, but in this case I use Shooter on an IPhone. It's simple and provides good data. Regardless of what app you use, you follow the same general steps.

First build the rifle profile. Measure and input accurate data with regards to sigh height. I've named the gun, input the barrel twist, sight height, and set everything to mils, and 1/10th graduations-




Then I go to "Ammo" hit the "+" sign, and a screen pops up. Select "from bullet library" as I know the bullet I am using will be in there.





A "bullet diameter" screen pop up. Select your bullet diameter- for this one ".224".

Scroll down to "Sierra" and "77gr Matchking (Litz). Select it and choose "G7" as it's a more accurate reflection of the bullet.



Next this screen pops up. You can change the name or leave it. Put in your actual muzzle velocity or what you guess it to be. You'll notice most everything was populated but the MZ Velocity, zero range and environmental data (atmospherics). I used a weather meter to get actual, but if you don't have one get as close as you can to the actual. I also set the zero range for "100 yards".

Now I know what this ammo will do as I see about 300k rounds of it shot a year, but I threw a random number of "3,000fps" in there to show the process.





Save it, and then select the bullet from the menu, and put In your target range "600" and hit "calculate" in the upper right hand corner and a drop chart is produced-





Ignore everything but the "path mils" column. At 600 it says I need "up- 3.5mil" in elevation to hit. Dial it into the scope-





Make a wind call (while I was hanging the target I checked the wind. 5-6mph full value).

Good pics and write up.

I love my milquads. Zeroing a rifle is a breeze now that I can measure with the reticle and the scope tracks.

I am not concerned with getting a prefect wind call, just getting it on target or close enough that I can see the bullet trace and splash. Also remove parallax if able. Even a little bit can screw your data up.




I decide to hold right edge of target and fire a round. It strikes just off the left edge and low. Using the reticle I see that I need to come "up .5" and hold a total of "right .7" mils.

Dial "up .5 and hold right .7" mils.



The result is a hit on the water line. I fire four more rounds to confirm-




I can see in the reticle that I am ".1 mil" low from splitting the waterline. Final elevation needs to be "4.1 mils" to center.

Go in the upper right hand of the screen and hit the box with the arrow in it. This pops up-

Select "velocity calibration".

This screen will appear. It will let you input multiple ranges and the actual adjustments needed to hit center. I used one range so put "600" for distance and "4.1" for the adjusted.




Go to the bottom and hit "calculate". The "trued" muzzle velocity will appear. Then hit "use MV". The system backward calculates the true muzzle velocity and changes your settings. Now the drop card reflects what you actually needed to hit- i.e. It has been "trued".



You can do this without the shortcut by manually changing the MV until the projected drop matches your actual.



After this we're done. The gun is zeroed and the ballistic program is trued out to 600 yards. It will now give you good data for all ranges 600 and in. I didn't hear, but you want to true if possible as close to transonic as you can. It gives you the best data. In all this remember- garbage in, garbage out. Input good data.












P.S. You'll note that there are no extra holes, no "whoopsies", no "flyers", no nonsense. Solid rifles, solid ammo, and solid optics with matching reticle and turrets is the easiest and simplest to use system that you can buy.

Thanks form..finally got a few mil scopes from swfa this sale instead of my usual MOA and will be referencing this post.

Great info, clear and consice.
That is certainly the most intuitive lesson I have ever seen on the subject, well done and thank you.

Just a quick question.
When inputting the gun data into shooter why is the correction factor for wind and elevation 1.0 instead of zero?

Sorry disregard that question, I gather it means corrections are in units of 1 Mil.

Good write up. Thank you for taking the time to explain! I need to check out the phone app. I've been doing it on my laptop, phone seems much easier.

Very nice.

Using the dots to measure is much easier than trying to hold the rifle steady while moving the aiming point to the POI, because there's always some wiggle error (not to mention the trouble caused by erectors that don't move, then do).

Thanks.

As others have said, very good write up and photos. You have made it much more understandable and I thank you for your efforts.

Does your experience lump in a three screen Oehler with the ubiquitous compact models?

Very good write up, thank you!

No problem fellas. Hope it helps.








Correct.





Oehler's are good. MagnetoSpeed's are good, Lab Radars can be good. I'm sure that you know but most of the commercial Chronos are garbage.

Great post, thanks so much for taking time to put it together... Rick oughta make it a sticky..

I have already sighted in my SS 6x42MQ and admit to converting inches to mils for the adjustment. I was only 1" low and 1" left. I adjusted to be 2" high at 100 yards. Next two shots straddled the verticle line 2" high. The adjustments were very precise. I am not used to that.

I had a little trouble determining which reticle mark was over the initial bullet hole but could easily see the grid marks on my target. That's why I converted inches to mils.

One question, if I refocus the eyepiece to make the reticle sharper will my point of impact be affected? Does it depend on the quality of the scope or what?

Thanks for the post. Lot's of information.

Nice!!





Take care, Willie

Thanks a hundred times. Wondered about the correction factors too. So - on a scope with 1/4 MOA adjustments I'd input, what?


Care to go into some atmospheric inputs on the Shooter app? Absolute? ASM? ICAO? Enable Zero Atmosphere? MV Variation?

Great post, Form! Nicely done with the pics and simple steps. I thought I might add a couple of thoughts to hopefully give additional clarification.

1. For anyone struggling to make the transition to thinking it terms of MRAD instead of inches, let's talk angular measurement for a minute. Mils (MRAD) sound weird and unfamiliar to most guys. It's really just an angular unit like degrees are, so let's call them degrees for this explanation. Most guys can picture a 15 degree or a 45 degree angle in their heads- it's a unit of measure that we're familiar with. Let's suppose you were throwing a baseball or football to a friend that is 50 yards away. You'd need to aim your throw up in the sky at perhaps a 35 degree angle in order to land the ball in your friend's hands. If your throw hits a little low, say at your friend's feet instead of at his chest level, you're not going to say to yourself, "okay, that hit 4 feet low, so at 50 yards 4 feet translates into 9.6 degrees, so I'd better aim my throw another 9.6 degrees higher, for a total angle of 44.6 degrees, in order to land the ball at chest level", you're just going to intuitively aim the throw at a little steeper angle, and it'll hit higher on your friend's body. Well this is similar to converting inches to MOA or MRAD when shooting. It's just a bunch of extra thinking and work to be converting back and forth between linear and angular units, when you could just think in terms of the angle. Unlike the baseball/football, you're not going to adjust your rifle intuitively (Kentucky windage), instead you're going to use an optical, angular ruler (reticle) to measure the adjustment angle needed, and instead of 9.6 degrees, it'll be 0.2 or 1.5 MRAD, or something similar.

There are 360 degrees in a circle. Now instead of picturing a circle that's flat on the ground like a compass, picture a circle that's standing vertical like a Ferris wheel. You can imagine that circle being marked with 360, 1-degree tick marks all around its circumference. Now instead of imagining 1-degree tick marks, imagine that the circle is divided into 6 slices (well 6.28 to be more exact), and the tick mark on each slice is called a 1-radian mark. Now picture each of those slices being divided up into 1000 pieces, and each of those little pieces is approximately a milliradian (MRAD for short). When you adjust 1 MRAD, you're adjusting the angle by one of those tiny slices. Now with that out of the way, let's go back to degrees. If you change the angle of your football throw by 1 degree, that's a 1 degree change whether your friend is standing 10 yards away or 50 yards away. Of course a 1 degree change will land the football only 1" higher at 10 yards, but would land the ball 5" higher at 50 yards. Now if you had an optical angular ruler and could watch the ball land low, you'd be able to measure the angle you need to adjust your throw by, and could try to throw 9.6 degrees higher (your arm doesn't have adjustable turrets on it, unfortunately). So whether your target it as 10 yards or 50, if you see a 1 degree correction is needed, it's 1 degree. If your target is at 10,000 yards and you see in your angular ruler that you need a 1 degree angle correction, that means you need 1 degree. Same with MRAD. If your reticle shows 1 MRAD correction needed, that's the same at 100 yards or 500. Of course that would translate into 3.6" at 100 yards and 18" at 500 yards, but we don't need or want to translate. Keep it in MRAD and keep life simple. One MRAD.

Now we often measure group size in MOA because of industry standard convention, but we could easily use MRAD for that too, except that nobody would know what we were talking about Aside from that, measuring target size, windage hold-off, shot correction, lead for a moving target, etc, are all measured/held using MRAD.

2. To the guys noticing that the elevation and windage correction factors are set to "1", this is something that needs to be verified if you're using your scope for shooting much beyond 500 yards. If your turret adjustments are 100% perfect, then the correction factor should be set to "1". If the actual adjustment is 0.99 mil per 1 mil (10 clicks) dialed instead of the advertised 1 mil per 10 clicks, then your correction factor should be set to 0.99. You'll need to verify whether your specific ballistic app uses the correction factor as the ratio of actual to advertised adjustments, or advertised to actual. With Ballistic:AE it's actual to advertised, so if you find that your turret adjusts 0.102 mil per click instead of the advertised 0.1 mil per click (1.02 mil actual adjustment for 1 dialed mil, if you dialed in 10 clicks), then the correction factor should be set to 1.02 (a ratio of 1.02 actual divided by 1.00 advertised). This can be measured and verified using a Tall Target test with an accurate rifle, as well as by setting up your scope in a fixture and testing tracking, or alternatively by measuring your reticle against a set subtension target at a set distance (to make sure your reticle is an accurate baseline), and then using an optical grid like the Bushnell magnetic boresighter to check that your turrets track properly as measured with your reticle. DON'T do this for your windage turret if you plan on using your reticle for windage holdoffs, that's assuming your reticle subtends true to form, as verified when doing the Tall Target test. Since we're using the reticle for windage, we don't care all that much what the turret does, and we want our ballistic app to spit out wind holds using the correct subtension of the reticle, not corrected for the actual adjustment increments of the windage turret. So if your reticle reads 5 MRAD, and that is truly 5 MRAD, leave the windage correction factor at "1".

This ensures that the ballistic app is telling you to adjust the ele. turret the correct amount, given how much each click is actually moving the reticle. At closer distances a 1 or 2% error isn't going to make a whole lot of difference in your shot solution (eg. 2.0 mil versus 2.04 mil), but can start to stack up when dialing in larger correction values.

Another excellent post.

This thread should be a sticky at the top...............

The correction factor really just refers to the percent error of your turret's actual adjustments compared to advertised. So if you select 1/4 MOA adjustments in Shooter or Ballistic:AE or any other good app, and your turrets truly adjust 0.25 MOA, then you'd leave the correction factor as "1". If it adjusts 0.23 MOA, then you'd enter 0.92 in for the correction factor. If one click adjusts 0.27 MOA, you'd enter 1.08, and so on. EDIT: This is how Ballistic:AE works, which is what I use, but it looks like the Shooter app does the inverse of this. So with Shooter, if your turret actually adjusts 0.23 MOA, you'd enter 1.087.

Absolute pressure refers to whether you're entering the actual air pressure compared to a vacuum, or if you're entering air pressure corrected for sea level. If you're located a few thousand feet above sea level, and you see a reading of 29.92 InHg, then you're reading relative, gauge, or barometric pressure. If you look at your Kestrel and see a reading of 25.62 InHg, then you're reading absolute pressure. Absolute pressure read off of a handheld device is preferred, as it bypasses conversions and local weather station input. FYI, if you have an iPhone 6 or newer, your phone has an air pressure gauge built in, and you just have to get the "Barometer" app to get absolute pressure readings from your phone without having to use a Kestrel or similar.

Enable Zero Atmosphere means that your app will compare your current shooting atmospheric conditions with the conditions present when you zero'd the scope with that load, and will calculate the difference in your zero for use in your current shot solution. If this is clicked off, the app just leaves your zero the same for any atmospheric condition.

I use Ballistic:AE instead of Shooter, so I'm not 100% sure, but I'm guessing that MV variation is a measure of the temp sensitivity of the powder you used in your load, and how much the MV changes for each degree F in temperature change.

ASM and ICAO are just two different atmospheric standards that bullet companies reference when advertising BC values. The Shooter app manual says this: "Berger, Nosler and Lapua all use ICAO. Sierra, Barnes, Hornady and Winchester use ASM". Not a big deal which you select, as it doesn't make a big difference.

The manual can be found here: https://www.shooterapp.net/manual.php

Note: Read the manual for whatever app you use, as the terminology used between different apps can refer to different things.

Thank you!

This and your previous post regarding proper scope mounting is undoubtedly the best posts in the Optics Forum in a looooooong time!

Kudos

Thanks for the posting Formidilosus, I have a Burris 2-10x42 XTR II and I love the mil radian turrets. Your write up is basically what I do. Site in at 100 yards and use the JBM Ballistics program. I only have access to a 500 yard range, but it works like a charm out to there.

If you are shooting at 200 yards (or further) instead of 100 can you use the reticle in exactly the same way, i.e. - just read the mils on the target and adjust accordingly to move POI to zero? Or is there some conversion? So far I've only shot my 10X at 100 yards so I haven't tried this.

I addressed this in my first post in this thread. The angle measured with your reticle is the same no matter what distance the target is at.

Very nicely explained. I'll be linking to this.

ILya

Thanks Jordan and I bet Formi thanks you too for saving him the key strokes!

Great stuff guys!

Thanks Jordan! Sorry, I didn't read all of your previous post. And thanks to Formi for the original writeup.

Tag

All of Form’s post holds true for ffp MOA scopes as well. Only difference is you would set adjustments to be .25 and swap it to moa

Great post Form, thanks much!

Now, I guess I'll have to get a smart phone.

And if you did that you'd be wrong. You've just illustrated why Mils is superior to MOA. A Mil is always a Mil, but 1" is not the same as 1 MOA. Just like 0.25" is not 1/4 MOA . 0.261" is 1/4 MOA. (one MOA = 1.047") It may not seem like much, but when you shoot long range small errors compound.

IPHY is Inch Per hundred yards and is also called SMOA.

Let me illustrate: 6.5mm 147 Grain Hornady ELD M @ 2800 FPS. I'll calculate both in MOA (1 MOA = 1.047") and 1 IPHY = 1.0" at 100 yds.

Drop in MOA @ 1000 yds. is 27.2 MOA

Drop in IPHY @ 1000 yds 28.5"

The difference is 1.3 MOA @ 1000 yds or 13.61". That a pretty large error and could be a big miss.

Windage in MOA @ 1000 yds 5.8 MOA

Windage in IPHY @ 1000 yds. 6"

That's only a net difference of 0.2 MOA or 2.1" Not much difference because it was compounded less.

Thanks to Form and Jordan for the schooling!

Sticky this please!

Also, sticky Form's scope mounting thread.

Correct me if I am wrong but I don't see anywhere where MallardAddcit said anything about inches at all. Just like one click on a MILs scope is always .1 mils regardless of distance. One click on a MOA scope is always .25 MOA.

Both MOA and MILs work fine....so long as you just leave any sort of linear measurements out of it. I agree that tenths are easier to work with in my mind than fractions but neither really is that big of an issue.

BTW great post Form the pics really helps with the explanation. Already sent this post to several friends to better help them understand what all them lines on the reticle mean and how to use them.

Great follow up info as well Jordan!

I agree this thread needs to be a sticky!

Gents,

Another great post, always appreciate it when those who know their schitt share their knowledge & experience in a non-inflated manner. Form and Jordan are two of the best at it.

Thank you for the information gentlemen.

When you needs some tips on applying Thread Lock let me know I'm sure I can get ya up to snuff

Jordan, have you been able to get Ballistic AE to use the iPhone internal barometer and gps for measurements instead of looking for data from a local weather station? I thought it was supposed to per the literature, but with cell and wifi turned off to test it, it fails to populate any weather data on my iPhone 6s. I only just downloaded Ballistic AE a few days ago though so I may be missing something.

I know the sensors on my phone work fine because Strelok does use the internal barometer and GPS, although I don't like the app layout as much.

As a side note, a handy iOS app I discovered recently is Density Altitude+; it's a very simple app that calculates density altitude from the device sensors and a temp input, which defaults to a local weather station but can be manually adjusted too. Well worth the $1.99 for the app.

If you had posted this before black friday they would have sold 3x as many of them...

Thanks for the tip on the Density Altitude app, I'll check it out.

The GPS doesn't get used to populate weather data, IME, but the barometer does get used to populate the absolute pressure box. Sometimes you have to click the "get weather" button, then click on the pressure box specifically for the measured pressure data to appear. I thought it was just a glitch that sometimes happens with my particular phone, but it might be more broad-based than that.

+1

Big fan of that set up. Wish I'd gone MQ instead of MD on mine.

And on a side note, I'd love to see that reticle in a 6x42 Leupold body and forget the turret.

tag

Thanks for the thread!

2 questions:

1) In the walk-through, Shooter back-calculated to an MV of 2860, but in the next picture, MV was listed as 2840. Why is that? A calculation issue? I'm not familiar with shooter.

2) Why in the world did someone come up with 'density-altitude' rather than just using station pressure and RH? What's the advantage?

There are only two things that affect bullet flight; air and gravity. Gravity is simple but air is very complicated. Air density- the medium we are shooting through- is dependent on temperature, pressure, altitude, humidity... you get the point.

Density Altitude is the real air pressure we are dealing with based on true altitude combined with temperature etc to give a more accurate representation of the density of the air the bullet is dealing with. Better data results in better solutions.

Cold air is dense, hot air is thin.

I've heard high air is thin, and low air is thick..... The lowlanders that come up here elk hunting swear by it.....

Get a pilot's license & "density altitude" will make a lot of sense!

Excellent information in this thread.
Thanks.

Is the free app istrelok any good or should we just pay the $10 for shoooter app?

The free strelok is really hamstrung, the $10 Version works great. Shooter is good as well. I use both at whim

as dennisinaz said, it's a way to simplify things; instead of using 3-4 different weather value inputs, you can use just one. FWIW temp plays a big part in this calculation even if the elevation doesn't change; for example in my area near sea level, we're at -1,500 to -2,000 ft density altitude right now (clear and cold weather), but it will change to 2,000+ ft d/a when it warms up a bit and gets cloudy, even without climbing the mountains.

Taking that a step further, you can print a dope chart for every 2,000 ft change in density altitude in your area and have your bases covered pretty well all year round.

This is good stuff - thanks for taking the time.

As much as I'd maybe like to, I can't get MIL going and I'm stuck on MOA.

One thing to consider. Some of the new rangefinders and rangefinder binos, with ballistic software in them automatically take many of these atmospheric conditions into account.Along with angle change ect. I have found the information that my leica HD b s gives me in mils has been spot on from below zero to hot summer temperatures. I still have a range card, but don't use it. I dial what my binos tell me. I have only shot to 800 with it,generally concentrating on shots from 500 to 600 for 1 shot kills on coyotes.

Me too....and one of the primary reasons is I'd have too much crap to switch over.

Are you guys still thinking in terms of inches of correction to make?

Yep

I'm that same way with lat/lon vs UTM but have no problem going back and forth between moa and mils, go figure.

Everything described in this thread applies to MOA as well as MRAD.

I totally rock mils as being 3.6 inches at 100 somethings. Kidding, sort of. I'll take that factor of ten stuff anytime anyhow though. UTMs too.

Thanks to Jordan and the others who are answering questions.







1). Screw up on my part. Corrected MV is 2,840fps.


2). One number to input versus multiple. Batter way to go.









The ballistic function is good, however in truly steep conditions at long range unless it's showing both straight line and corrected distance your wind corrections will be wrong. Just something for people to keep in mind.

This is generally what happens within a day or two when die hard MOA users learn to use both MOA and mils correctly-


"Wow both are just numbers that I spin to and they both work the same"

and then

"Wow, you know mils is easier to see and count on the reticle"

and then

"Wow, the drop corrections are easier to remember in mils"

and then

"Wow, wind brackets are easier with mils"


And then....



"I'm selling all my MOA scopes".





Seen't it. DOZENS of times.

Wind holds in the high country suck. It may change twice especially being above the deer shooting down into a basin. Solution: for me get closer. I have found with my geovids on very steep downward angles that there is .1 mils less per 100 yds hold, than a shot with little to no elevation. That is a rough calculation, but pretty consistent.

*

That's pretty much it. I've seen it a bunch of times, myself, after going through that very process myself several years ago. Though I ran both MRAD and MOA for a while while I transitioned the majority of my herd over to MRAD.

I would add this, though- "Wow, you know mils is easier to see and count on the reticle, and the turret".

I don't see how it simplifies anything. If you know the current barometric pressure at sea level, plus your temperature and altitude, you can calculate your station pressure. That's important because it tells you that station pressure accounts for both temperature and altitude. That means the only additional thing your ballistic solver needs besides station pressure is RH*. If you use corrected pressure instead, then you also need temperature and altitude in order to calculate your station pressure.

D-A basically gives you station pressure + RH, and then 'corrects' or relates it to some altitude where you _would_ be if everything was at the mythical ICAO 'standard' pressure. That's fine, but it actually _adds_ a level of complexity and abstraction to things, as far as I can see.

*Actually, I'm not convinced RH is a factor if you're using station pressure, but I'd have to review a bunch of stuff to feel confident of that.

So, what am I missing?

Okay, thank you. I'm less confused now. (-:

be interesting to see at what velocity/BC/distance that temp RH and air pressure make a 1 inch difference in POI.

I really don't know.

I expect to hunt between 4500 and 9500 feet ASL

temp between 0 and 90 F (30-60 F most often)

BC - .350 probably (is that officially a ping pong ball?)

distance 100-250 yards.

ps appreciate the original post. useful, easy to understand, helpful same as how to mount bases, scopes, rings (degrease, degrease, degrease)

You're right about the calculations, though RH does affect a ballistic solution, because it changes the effective density of the air, regardless of air pressure. Water vapour molecules are actually lighter and less dense than air molecules, so high RH decreases the air density. The effect of RH on air density is minimal, though, compared to pressure and temperature.

The way DA simplifies things, is that there are devices that use sensors to take the measurements and spit out a DA number for you to enter into your ballistic app. That way you don't have to manually take 4 measurements and enter each in separately. If your ballistic app is equipped with on-board sensors to take all necessary measurements, then it doesn't matter which air density calculation standard you use, except that you need to remember that the fewer measurements you can take, the better, as each measurement introduces error into the calculation. So measuring absolute/station pressure directly is better than taking a barometric pressure measurement and then calculating the station pressure using a temperature and altitude measurement.

They are, and if you got drop charts in your hand they are just the same. It's just simpler for me dealing in 'inches'

Does a critter hit with MIL adjustments die quicker than one hit with MOA adjustments? Thanks

At 250 yards it's pretty negligible.

Assuming 2900 fps MV, at 250 m your bullet will drop the following amounts from a 100 m zero:

4500 ft ASL, 0F
9.1"/0.9 mil

9500 ft, 90F
8.4"/0.8 mil

Not even a 1" difference. At further distances the differences become very large.

I need to know the value of each, then I`m good to go. Once I knew that .1 mil = .36 inches, no more quesswork. My MOA/Mil dot scopes are just as easy (SS10x42 MIL dot x MOA glass for instance. BUT, these scopes need to be used, frequently, to keep the mind in the game....at least my mind.
I have gone to a brainless solution, in that I make my own drop tapes to place on my turrets. Figure the balistics, shoot to conferm, then the tape in 50 yrd increments goes on the dial. Range, dial and shoot. Should I go to a different bullet, velocity etc. I make a new tape, keep the old one in the bullet box for a change back. For you computer guys, all you need is the dia. of the dial..break that down into moa or mils. My son prints these off for me so I got lotsa spairs. But I shoot almost every day, retired, 5-6 different rifles with these scopes on em..I also have several different places to shoot at distance. I`m lucky.

As a mathematician this statement is killing me.

Troublemaker.

I`m not,...so Why?

There's only one range at which 0.1 Mil = 0.36"

Um, my quess would be 100 yrds? Then .72 at 200, 1.08 at 300 etc

Or .25 at 100, .50 at 200, .75 at 300 etc. Like I`ve already admitted, I`m no Mathman....so are these correct?

A milliradian is an angle, an inch is a length.

and as a spelling nazi, this is killing me.......grin

Thanks Mathman. But for me .36 inches works.

It's all good. Whatever it takes to get a feel for it. But that way of thinking gets weaker further out where a Mil is a Mil is a Mil and there's zero need for inches. I have had to think in 0.36" when using targets with inch grids where I could not see bullet holes in the scope, lacking a Mil spotter.

A whole(hole) thread on how to site in a rifle. It’s glorious this place is full of [bleep] morons. Next week some one will do a shoe tying step by step and you poor retarded [bleep] can stop tripping on your laces or depending on your mommas.


Formillous you keep showing these guys all your tricks they will be setting in that black hawk with you.

Wow, Freddie!
Four complete sentences - congrats, tiger.

You calling-out anyone out for being challenged is NEVER not funny.

GregW gave me this tip, and I think it's a good one, at least for me it is. On the drop chart thing, I have a column for Wind correction in Mils, and one right beside it I have a column for wind drift in inches. Since I'm familiar with how big a deer is, or aoudad, antelope, etc, it gives me a good mental image of what the wind is supposedly doing at given ranges. It simplifies things for my feeble (and newbie to this Mils stuff) mind. Obviously I hold for wind with the Mil hashes (SWFA 3-9) but I like knowing the inches in drift as well. Call me weird.

Good stuff Formid. Thanks for taking the time. Jordan as well.

Thanks. Kinda figured you would be at the range doing some site in now that you got the skinny on how to. LOL. Kill any elk this year Scotty. Seem Donny got a creedmoor cherry while back.
This is not as good as the how to open a box of nosler bullets but it’s gotta be close.

Laughing....

Isn't that the truth.