Question 30 plus moa mounts

[NDAR15MAN]

Is there a math calculation that can show if a 30 moa mount might be to much to get a specific caliber of bullet on the bullseye at 100 yards ? I was not the smartest guy in school and might not even be smart enough to perform the calculation even if there is one. Just wondering. I would think it is all math ? Must be away to tell this info before going out and buying a 20 or 30 or 40 moa Mount. I know it also depends on moa of scope , height of scope , caliber of bullet , speed of bullet , BDC of bullet and maybe even more stuff. Just wondering if there is a easier way to find this info instead of buying stuff and finding out no , you have to return the stuff you bought and buy this or that thanks. Marty

 

[Zero333]

Basically if the scope has 70 moa (or more) of total elevation travel you'll be good to go with a 30moa base no matter the cartridge you're shooting.

 

[dkhunt14]

I believe if the scope is mounted on a zero rail and you click down to max and count the minutes left, it will tell you what you need. This is at 100 yard zero. Matt

 

[NDAR15MAN]

Looks like a little difference of opion here. So let’s fine tune QUESTION a little I guess. Ruger M77 **** 6.5 creedmoor cal gun , Sightron lll 10-50x60 moa 2 reticle with 50 moa total travel on scope. Using a federal 140 gr open tip bullet factory ammo , this works better then any reload I have come up with in this gun. at 2817 FPS. I hope I did leave out any other critical info. Questions I need answered are the size moa rail mount needed , size of 30 mm Burris Z ring height , and what moa number of Z ring insert needed and What is the maximum yard I could click to with a 100 or 200 zero if I could even do it ? I need a 100 yard or 200 yard zero ( hardest part of this question ). What i Need is optuim size moa scope mount for gun and optuim size burris Z rings to give the maxim total yardage I can click to with above said scope at 100 or 200 yard zero ? Ha ha ha what a math question. I think Einstein would be only person that could answer this question I think. Ha ha ha. Let me know your thoughts. If you can answer this question and be correct and 2 readers here say yes the man that answered question correctly .... $25.00 Cabela’s gift certificate coming your way by me to man that answered correctly after I sight gun in. Could take a few weeks to prove it out. Ha ha ha. THE CORRECT Answer is worth $25.00 to me to keep returning a bunch of stuff to Brownells that will not work for the answer. Ha ha ha. Marty.

 

[NDAR15MAN]

South Praire please take another crack at question. Like I said what is longest yard distance I can dial or click out to with your answers you gave ? The very best set up for the longest yardage I can click too with given info. I want to know the maximum range I have with a mount and rings and scope. And what are the moa mounts and moa rings used to do it with the sightron I have. Is there a set up that can get me to 1500 yards , 1800 yards or 2500 yards with answers you supplied and still have a 100 or 200 yard zero. If so what is that set up and max yardage. Thanks. Marty

 

[NDAR15MAN]

Another reason i want to know the max number of moa clicks I can go out with this set up is it will give me a rough idea for maybe a little bigger cal gun too with the same scope etc. Thanks Marty

 

[dkhunt14]

Another reason i want to know the max number of moa clicks I can go out with give set up question it gives me a rough idea for maybe a little bigger cal gun too. Thanks Marty

I doubt if you'll make 1500 yards with a scope that only has 50 MOA in it with that caliber and velocity.

I thought the Burris rings come with all the inserts. So if you get a 20 MOA base and use the Burris rings, you will just add what you need to get a 100 yard zero and be on bottom of adjustment. Nobody can tell you how much you need because all guns shoot different. Where is the barrel indexed at and how much. Nobody knows. You will have to shoot with the 20 MOA base and see how much you have left and add it to the rings with the inserts. Matt

 

[Dusty Stevens]

^exactly

 

[Bart B.]

When doing the simple math regarding rail angles and bullet drop using a scopes adjustment range, the scope adjustments's mechanical mid point (both E and W) may not put the reticle dead center in the main tube's center that aligns with the rings. Many scopes have more adjustment range up and right from the main tube (optical) center.

 

[Bart B.]

This will tell you in Inches/MOA where your optical center is exactly.

Firtst I've heard of this method. Differs from the scope designers' method which it all relative to the scope and is always the same regardless of range, rifle, ammo, mounts nor human.

What if the W and E adjustments have several MOA movement on the knobs past where the inner erector tube stops against the outer main tube? The inner tube and reticle doesn't move across the target image as the adjustment moves away from that tube.

Will this method of zeroing the adjustments have the same results as spinning the scope tube in V blocks then moving adjustments to where the reticle center spins centered on the main tube axis?

 

[Bart B.]

Check your own scopes. If you know how. And not fudge the numbers.

How old was the last one I checked that did that?

What if others check their recent top quality scopes and see that happen?

What if you answered my last question about using V blocks?

 

[Bart B.]

I was not talking about 2 different things; all is relavent and the same thing. Doctoring to be more relavent.

Test your own scopes. I know what I'm talking about. Don't be afraid of being wrong.

Answer my question regarding V blocks.

 

[Bart B.]

Your V-Block method will not tell me what yardage will be my optical center. It will tell me where the center of scope travel is at, per the scope, but not at all per the scoped rifle.
Listen to your own advise: "don't be afraid to be wrong"......

All scope company blueprints' have their optical axis centerline dead center on the outer and inner tube's axis.

Once the inner tube is adjusted for rifle zero or range, they become part of the line of sight axis. The optical axis from the center of the objective and eyepiece lens plus the main tube stays the same; they don't move

 

[Bart B.]

Can't answer about your NF scope yet.

The scope optical center is the axis from the center of its front lens to the center of its back lens through the main tube center. That never changes. Scopes' LOS axis does.

To see what ranges the scope adjustments are good for a given load at different ranges after getting a 100 yard zero, count the units up in elevation up from that zero it will move until the reticle stops moving. Convert that number to MOA then compare that to what ballistics say bullet drop down range past 100 will be.

Then count windage units each side of the longer range zero watching reticle move to see what maximum wind correction can be adjusted for. Sometimes there are more to one side than the other.

 

[NDAR15MAN]

Bart B. I think you might have the correct answer here to my question. If know one comes up with a better answer by Friday night you are the winner of gift card. Marty

 

[NDAR15MAN]

domorn..... you are correct I added a sentence to my question because I had not reread my question / questions for the prize. I don’t want people to think I wronged you. Pm me your mailing address and I will be glad to send you a gift card from Cabela’s. As of now looks like BART B has completely answered all questions but waiting if any one can prove a better or faster way to answer questions . Thanks dmoron for your help. Marty the man with all the questions but no answers. Ha ha ha

 

[JFrank]

@NDAR15MAN

My only reply to you, and anyone else, is Post #13. Take from it what you want
The rest are to @Bart B. exclusively and solely.....

Good Luck and Best Regards

Wow' good stuff guys I think I need a nap.
J

 

[JFrank]

Can't answer about your NF scope yet.

The scope optical center is the axis from the center of its front lens to the center of its back lens through the main tube center. That never changes. Scopes' LOS axis does.

To see what ranges the scope adjustments are good for a given load at different ranges after getting a 100 yard zero, count the units up in elevation up from that zero it will move until the reticle stops moving. Convert that number to MOA then compare that to what ballistics say bullet drop down range past 100 will be.

Then count windage units each side of the longer range zero watching reticle move to see what maximum wind correction can be adjusted for. Sometimes there are more to one side than the other.

Very interesting,
I myself find optical center by turning my turret all the way up counting revs then the other way split the difference and that's it.
Just me of course.
J

 

[Dusty Stevens]

Very interesting,
I myself find optical center by turning my turret all the way up counting revs then the other way split the difference and that's it.
Just me of course.
J

Put it up to a mirror to get it centered close enough. Bart could even do his test to see if the turret has more windage and elevation one way than the other without worrying about the v-blocks.

 

[Bart B.]

Put it up to a mirror to get it centered close enough

I've used a mirror and the results are within a couple clicks of what V blocks do. Both are equally best.

Just learned all Vortex scopes' knobs go different click counts past where their erector tube stops against its mechanical limits right and up. Their bias spring limits adjustment left and down as many scopes do. Varies across their different models.

Awaiting word from Nightforce. Both Nightforce scopes I checked a few years ago had a few to several knob clicks past reticle stopping at its limits up and right.

Here's the best explanation of how scopes work I've found.

https://patents.google.com/patent/US4643542