POSP scope question

[krolden]

Okay, have a question that may require some math.

I am looking at this scope at Kalinka Optics. I have bought from them before and things go relatively smoothly. However I notice that this scope, along with another scope I have has an MOA of 1.8 at 100m. My other scope that isn't variable has the same layout.

Now I was looking to get another scope, a Trijicon but I noticead that the MOA was 3 inches at 100 yards.

When I converted cm to inches for my POSP scope, it came out to 1.96 inches (5cm) at 109.36 yards. So it would seem as though the POSP scope is a bit more accurate. (however I cannot use the bullet drop compensator as it is not designed for .223 but the website claims it works with all calibers which I haven't figure out...or maybe it would work since gravity pulls on all objects at the same rate...I dunno....didn't major in math).

Am I correct in this or the Trijicon have a better MOA? Please help

- Signed
Mathematically challenged

 

[MartinS]

A Minute Of Angle, MOA is an angular unit of measurement that works out to around one inch at 100 yards. It is not a characteristic of the scope, they are just telling you in both centimeters and Minutes Of Angle how much the point of impact will move per one click of the elevation and windage dial. A smaller number means a finer adjustment
Gravity does accelerate all objects downward the same amount, but a 5.56 round will arrive at the target sooner than a 7.62X39 round and so will have less time to fall down.

 

[krolden]

Roger that Martin, I understand how MOA works, but what I don't understand is the "click" difference of the two scopes. Why would a surplus Russian scope be more precise (in terms of clicks) than a scope costing more than $1k?

 

[Grump]

Sorry dude, it's a math thing. The Trijicon is 3 clicks/MOA, not 3 MOA PER click. IOW, 1/3 MOA, which is a lot finer than 5 centimeters per single click at 100 meters.

The Trijicon is slightly more than 1/5 more fine than the Russkie job you're considering.

"Coarse" M1 Garand 1-minute elevation and windage clicks equal, nominally, 2.54 cm/click (some sources say a bit more but less than 1.5) are more fine than the Russian scope.

 

[MartinS]

It's a puzzlement. Bigger clicks do make elevation changes faster if you're in a hurry. Please post which one you get and how it works out for you.

 

[RyanM]

Well, if you can live with a fixed magnification, this scope

http://www.kalinkaoptics.com/detail.aspx?ID=556

Has a mil-dot reticle, and 1/2 MOA clicks.

Also, on the bullet drop compensator, I think they mean it only works for 7.62x39 and 7.62x54R. On a x39, the chevrons are 100 m, 200 m, and 300 m. On a x54, they're 200 m, 1,000 m, and 1,100 m, or something crazy like that.

 

[krolden]

Is the ACOG variable magnification, I assumed it was fixed?

Grump, if its not to much to ask could you break down the math thing, because at first I assumed 1/3 but the literature just says 3 MOA at 100 yards...which I translated totally different, which seemed odd that a old surplus scope would be more accurate.

Speaking of which, with these types of clicks and changes that would equal about 5 inches or a foot at certain distances...what are they supposed to be used for? Seems if you mis calculated you're head shot may end up being a knee shot with these. (or just flat out fall 10 feet short of the target)

 

[RyanM]

The Triji is a fixed power, looks like. Also, the Triji scope specs on that website say:

Adjustment @ 100 yds (clicks/in) 3

3 clicks/in. Meaning, 3 clicks per inch. So each click is 1/3rd of an inch at 100 yards. Compared to more like 1.75" for a standard POSP, and 1/2" for the Pro models.

I'd go for the fixed 6x42 POSP I linked to, then. 1/2 MOA per click is precise enough for most people, and a Mil-dot reticle basically gives you a rangefinder and a bullet drop compensator in one, if you can work a ballistics calculator.

Here's a reference sheet I made a bit ago for regular old 7.62x39mm AKM. Bullet drop and simple rangefinding for a 5' 8" person. You can basically use any three dots for the first 300 meters and not be too far off (provided it's zeroed right).