Rifle Scopes Beginner Question

[IA Precision Shooter]

Hello all. I have somewhat of a basic question I'm hoping someone here can answer.

During my time in the military I only used Trijicon optics, which were easy enough to manipulate. I actually prefer iron sights for most things.

I'm getting myself a bolt gun and was looking to put a US Optics scope on it. My question is this:

If a scope is zeroed and I make an elevation adjustment. How does the reticle know the difference between rounds? For instance I zero at 400 yards and click to 500 on the scope. A .308 round will drop at a significantly different rate than a 22-250. How does that work? (I'm assuming the elevation adjustment is listed x yards-n yards on an old Bushnell scope my dad gave me)

If my question is unclear or not valid because of my lack of knowledge please let me know. Obviously I can just do the math and make a table for my scope that says a .308 round will drop n inches between 400 and 500 yards so if my scope adjusts at 1/4 moa I need to click x number of times to compensate. Something is confusing me about this though.

 

[dpodgurs]

Re: Beginner Question

Are you talking about a scope with a ballistic drop or one with .25MOA / 0.1 mil adjustments? The reason I ask is if you get a scope with moa or mil adjustment then your adjustment is going to be a direct result of the math used to come up with the elevation adjustment.

A ballistic drop has a general adjustment set which gets you in the ballpark but is by no means exact. Welcome to the hide!

 

[Rhenerie]

Re: Beginner Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: IA Precision Shoot</div><div class="ubbcode-body">
If a scope is zeroed and I make an elevation adjustment. How does the reticle know the difference between rounds? For instance I zero at 400 yards and click to 500 on the scope. A .308 round will drop at a significantly different rate than a 22-250. How does that work? (I'm assuming the elevation adjustment is listed x yards-n yards on an old Bushnell scope my dad gave me)

If my question is unclear or not valid because of my lack of knowledge please let me know. Obviously I can just do the math and make a table for my scope that says a .308 round will drop n inches between 400 and 500 yards so if my scope adjusts at 1/4 moa I need to click x number of times to compensate. Something is confusing me about this though. </div></div>

Think of Elevation or windage adjustment as changing the angle between barrel and reticle. Most scopes today are calibrated in MOA (Minute of angle) or MRAD (Milliradian). Every change in bullet/Drag/velocity etc etc will change bullet drop. So 400 yards to 500 yards has to be calculated base on your individual load. For example the differance for my rifle between 400 and 500 yards is 1.2 Mils or 12 clicks up. that is relative to 21.2 inchs or 4 MOA.

Welcome to the hide. There is alot of information here that will be very helpful

Edit: You can have a "Ballistic drop compensated" turret that would be 100-200 etc yards, however again that calibration would only be good for one load at one density altitude and under one set of atmospheric conditions.

 

[IA Precision Shooter]

Re: Beginner Question

Thanks for the help, I get it now. I've been lurking for years. Couldn't find an answer directly so I figured I'd sign up.

 

[Rhenerie]

Re: Beginner Question

No problem, I hope it made some kinda sense lol