click value

[4runnerman]

Maybe dumb question here. MOA and click value. Is it based on bullet weight,MV and bullet CF or does the caliber even matter

I mean a 30 cal bullet is 30 cal. 308 or30-06.

[Jim Watson]

The question should probably be in Rifles or Accessories, not reloading, but while we are here...

The click value on a scope sight is purely optical. It moves the image of the reticle the same whether it is on a .30-06 or a .22 short.

A minute of angle (MOA) is very nearly one inch PER HUNDRED YARDS OF RANGE. 1 MOA = one inch of POA change at 100 yards, two inches at 100 yards, three inches at 300 yards, etc.
Clicks on scope adjustments are most commonly 1/4 MOA these days, but will be found at 1/2 or 1/8 on some models.

[.45 Vet]

The value, (amount of movement per click), is purely up to the scope manufacturer.

[4runnerman]

Yes I understand all that,My question is- The Caliber- Does it matter?.

Say 243 and 6MM-Both shoot same bullet, So,What I am asking or wondering is does the caliber matter as long as the bullet is the same?. As in 243 and 6MM
As long as I have Bullet Wt,MV and Bullet Coeficany.

[LE-28]

It would matter if the case volume is different between the calibers. The caliber with the higher case volume would have lower pressure then the case with the lower volume. This could and probably will affect the POI between the two.
Between 6mm and ,243 their isn't a lot of difference in case capacity but .308 vs 30-06 vs 300 Win Mag and so on would have a much higher difference in case capacity thus affecting pressure and POI with bullet and powder charge being equal.

[4runnerman]

le28--Does that matter?. Yo have MV- Once bullet is out of barrel ,does pressure matter?.

[Gabe1519]

I'm not sure I have an exact answer to your question but there is an app you can put on your iPhone or what have you. It calculates the reticle adjustment you need from input parameters such as distance, angle to target, wind speed and direction, bullet size, velocity, scope type, etc. it's called Strelok and I think it will provide a better answer than I can give. I think it was free the last time I downloaded it. Never tried it though.

[4runnerman]

gabe- That's what I did ( I hate figuring out clicks ha ha). The app does not have 6MMBR in it. It has 243 and 6mm though. That's what prompted this question.
Can I use 243 or 6mm and just put in my bullet wt,mv and coeficany and get a good answer?.

[LE-28]

Your right, I misunderstood your question. You apparently are varying your powder charge to maintain the same MV between the calibers.

I don't know for sure to be honest, barring the rest of the variables, (barrel twist rate, barrel length, chamber tolerance and so on) I would think the same adjustment to POA should be really close to the same POI on both calibers.

Trying to load shells for two different calibers in two different guns to react exactly the same as POI with the same scope adjustment will prove to be a real challenge.

[Gabe1519]

Hmm. I guess the only way to find out is try it out at the range. I would guess you can get pretty close if you use a similar bullet weight and velocity that is in the app already. I haven't heard any reviews as to the app's effectiveness but is sure like to find out.

[Gabe1519]

In my search for more info about the 6mmbr I found this

http://www.6mmbr.com/6mmbr.html

It has just about everything you want to know about reloading the 6br and at the bottom has ballistic comparison information with the .243 and others. It's an interesting looking cartridge I've never seen before.

[4runnerman]

Gabe- It's un real accurate. I love it. Last month or so I shot a .151 5 shot group with it.

[4runnerman]

I think maybe I am not wording this right ( my fault). I have a program that tells you how many clicks ( MOA ) you need to go. Input fields are MV, zero distance, Bullet wt and Coeficany and MOA Value (1/4 for my scope). Then all you do is put in how far you want to shoot ( say 600 ) yards hit enter and it will tell you to go say 27 clicks. It has 243 and 6mm ( i need 6MMBR ). If I enter in 243 or 6mm cartridge field and put my 6MMBR info,will the click value still be right.

[Jay24bal]

Input fields are MV, zero distance, Bullet wt and Coeficany and MOA Value (1/4 for my scope). Then all you do is put in how far you want to shoot ( say 600 ) yards hit enter and it will tell you to go say 27 clicks. It has 243 and 6mm ( i need 6MMBR ). If I enter in 243 or 6mm cartridge field and put my 6MMBR info,will the click value still be right.

If I understand your question after you rephrased it, the caliber should not matter. Assuming you know the muzzle velocity for sure via a chrono, your zero, bullet weight, and BC, the caliber of the bullet should not matter.

[4runnerman]

You got it Jay. I know all those fields.

[Bart B.]

Click values. . . .

For powder measures, the volume of the metereing chamber changes a fixed amount for each click on its adjustment. Different ones will have different amounts of volume per click. For a given setting, different powders will have different amounts of weight change per click. There is no standard. It's easy to make your own click vs. weight change chart.

For sights, the change in angle between the line of sight and line of fire varies all over the map. It depends on how much physical change there is between these two axes per click and has nothing to do with the rifle barrel bore or cartridge dimensions, just the bore axis. In the USA, a "minute of angle" was originally set up by the NRA and sight manufacturers a century ago as exactly 1 inch per hundred yards of range. As the scoring rings on bullseye smallbore and high power match rifle targets were (and still are) spaced on even inch increments, everything had the same reference and made adjusting sights easy. Metallic sights had lead screw thread counts of 40 tpi so 1/3 of a turn moved the sight .00833" which is exactly 1/3600th of the sight radius standard of 30 inches. Externally adjusted telescopic sights had their adjustment screws also at 40 tpi but had 50 clicks per turn. With a standard 7.2 inch spacing of their mounts and the rear mount adjustments moving .0005" per click, that's also exactly 1/3600th of the mount spacing. There's 3600 inches in 100 yards. Internally adjusted scopes angular change value depends on the mechanical design and lens focal length tolerances; they're close to inches per hundred yards, trig MOA, or some mil standard of which there are four different ones used on earth; whatever the maker wants.

But the sight's click values changed when someone didn't like the easy method and demanded they be the trigonometry version using the sine of 1/60th of a degree on angle for one MOA:

1.047197536428328546947470696664. . . . . . .(ad infinitum) inch per hundred yards.

But none of the target printing companies make 100 yard targets with 1.047197536428328546947470696664. . . . . . .(ad infinitum) inch spaced lines on them to match the trig value of MOA. But one could set one of these inch spaced lined targets at 95.5 yards and the lines would be close enough for trig MOA's spacing.

[4runnerman]

Thanks for all the replies guys. I did some work on it . I choose the 6 mm. Plugged in my info from the 6MMBR. I know from shooting F Class at 600 yards with a 300 yard zero that I need 29 clicks to be dead on at 600 yards. After inputting all my info ( zero range,MV Bullet Co,Bullet wt, Scope adj ) I hit the shoot button- Darn thing came out with 29 clicks. with a 46.4 inch drop. This program could be the cat's meow. I hate figuring out how many clicks.

Program is called- LetFly- Cost's .99 cents. has a amazing amount of cartriges to choose from. It even will tell you your drift with wind input. You can save your special settings. Once you do, all you do is tell it the distance you are going to shoot,hit the button and bam it is done.

Tells you, Flight time, MV at target, FT lbs at target and drop,Plus how many clicks on the scope to go

Now- 8 more rifles to enter into it. All on your cell phone and fast.

[Bart B.]

What's the "scope adjust" input options?

I ask because of all the different click amounts across all the scopes.

[4runnerman]

Bart--Options for scope settings are 1, 1/2, 1/3- 1/4- 1/8- 1/10. Can also choose MOA or MIL. gives options for sight above bore,zero range in yards or meters,elevation sea level,barometric pressure,relative humidity, temp outside.

when you hit the go button info that displays is

Bullet- fps/bullet wt/and bc
Sight- zero range and scope moa setting
Weather- temp and sea llevel
Target distance shooting , sea level and wind mph
below that is another set of info including[distance shot again with flight time/impact speed at target/energy at target/drift/rise or drop in inches /and scope clicks needed to shoot that distance