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After my zero question


Cali_Ed

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Not sure if I'm in the right section guys, but after my 100 yard zero do I just increase the magnification to increase the yardage? Or what's the proper way of let's say shoot up to 600 yards. Do I use the hash marks on reticle? Or will i still need to mess with the turrets?

First time with a scoped rifle so I apologize for all these questions

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unless your scope is FFP, the subtensions in the reticle will equal different measurements at different levels of magnification. the distance from one line to another at 10x is not the same at 20x. your reticle will only be accurate (1dot section = 1 mil) at a specified power. any other magnification level and you need to do the math.

there are some handy ballistic calculaters you can download for free. they do all the work for you and can tell you how many clicks to adjust or how far to hold. I have one called strelok that is fun to play with.

Edited by blue109
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  There is a web site you should visit, it's called rex reviews or tiborasaurus rex.  The site talks about rifles, techniques, and optics.  It's like crack to a long range rifle junkie.  It is great watching, being a you tube channel.

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Ed,

 

Use the LRBC app on the vortex website.

 

http://www.vortexoptics.com/content/lrbc

 

If you are having problems figuring out what data to put where, let me know and I can input the data for you and generate the PDF's of the reticle at dfferent magnifications.

 

Looked it up and figured out that the mil-dot reticle is calibrated for 14x on your SFP scope.

 

Here is the reticle chart in MILS (mrad reticle) for FGMM 308 175gr SMK HPBT  (see attached PDF). Your reticle at 14x is "similar" and the mil dots match up to the major MIL hash marks (i.e. 1, 2, 3, 4) on the mrad reticle.

 

post-14035-0-90675800-1404801617.png

 

You'll also notice that the following image (right) is pretty close to the reticle chart, since the image is set up for 168gr projecticles.

 

bdc-vs-mil.jpg

14xVortex Optics - LRBC.pdf

post-14035-0-90675800-1404801617_thumb.p

Edited by shibiwan
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So on the first image the center where both horizontal and vertical lines meet is 100. Then on the next major hash marks it's jumps up by 285 yards to end up at 385? So then its not a consistent increase using the hash marks because then it jumps up by 185 to end up at 570 or am I looking at this wrong?

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the bullet doesn't make a perfect arc...and each round will have different characteristics. a hot loaded 150 isn't going to hit anywhere near a subsonic 175. there isn't any simple answer here. you need to either cheat like I do and get a ballistics program, or you need to spend a few days/Weeks on the net reading up on all this. I've done enough reading to have a general idea how it works, but I don't have the time or resources to practice the art so I just plug numbers into my app and it tells me how many clicks to dial up. if your setup/ammo is consistent you can make a little cheat sheet.

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So on the first image the center where both horizontal and vertical lines meet is 100. Then on the next major hash marks it's jumps up by 285 yards to end up at 385? So then its not a consistent increase using the hash marks because then it jumps up by 185 to end up at 570 or am I looking at this wrong?

 

It is not a consistent increase since the bullet's trajectory is parabolic (curved) the deviation/drop from the zeroed point at 100 yards increases exponentially for each incremental distance. The MIL reticle has a uniform hash marking. This is primarily for range estimation, and coupled with the right bullet drop chart, makes it universal, from a caliber/load standpoint.

 

You'll notice caliber-specific BDC reticles have an exponential reticle. The holdovers are spaced out farther for longer ranges.

 

e.g. Nikon M308

NIKON-M-308-4-16x42-Riflescope-BDC-800-R

 

e.g  Safariland BDC 800 reticle

opplanet-safariland-rr-800-2-reticle.jpg

 

e.g. Bushnell BDC/DOA reticle

rs_bushnelldoa_200906-a.jpg

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 I think you are better off not paying too much attention the the MilDots & use your Turrets for adj. for adding to or subtracting for range . If you sight in at 100 yards , thats your zero on the turrets & how many clicks for windage or elevation , at different ranges is what I use ,Once I set my zero  , for example , mine are set at 100 yards , I have with a 168gr. load , its three clicks up & two clicks left for me to center @ two hundred yards , from my 100 yard zero.

  I Make notes or a dope chart for what bullet weight or load I use & I can always go to the notes to go to the right amount of clicks for them . Some tape these to there rifles for easy viewing .

 As said above , the MilDots or hash marks or BDC are just reference & will most likely never match up to different loads you are using . They are also as said for range estimation or quick shooting , Kentucky windage /elevation.

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