Vortex EBR 556 reticle ranging "Adjustments"

[AlamoShooter]

I got to be short this morning, But one thing that clouded my brain was the Fixed yardage lines on EBR and like Reticles that were for the "standard" NATO bullet

The Vortex Razor reticle has a ladder that let us range targets quick out to 700 yards. And give us the hold (for the standard round)

I figured I would just have to learn how to hold over a bit or under a bit to Match my bullet and load. my 55 gr bullet travels just under 3,100 FPS and my 69 travels at 2700 Close but not exact in each range . what I had to do with the Meopta was make a 1 min adjustment for my 69 gr load to my 55 gr load.

Now Life is Good & "I see clearly now"

The Razor reticle has a 100-200 center line to sight the gun to

a 4.4 MOA drop to 300yards

8,0 MOA drop to 400 yards

my loads drop 55 drops 3.46 to 300y & 7.8 to 400y that fine

The 77 gr load at 2600 drops 4.9 at 300Y & 8.89 at 400y and out at 600y the drop is19.3

So this is the Dumb as me Fix Sight the 69 gr and the 77 gr loads at 175 yards instead of 100 yard sight in and the drop is fixed my 77 load drop rite in the Razor's Reticle lines so each distance out to 700yards match up with in 1" or so in stead of with in 1 moa.

I will post a graph later so that you can match up your Ballistic chart to you load and bullet by simply adjusting your sight in distance.

I know most of the smart guys already know that, This thread was for the Dumb as Me bunch = all two of them.

If it does not help the visit count would be real low

[outerlimits]

Jamie-you've finally stumbled over what ACOG users have had to do for years...simple solution, ain't it?

[Corey]

I wonder if such an idea would work for other reticles and custom loads (Burris XTR in my case). I'm a little math stoopid sometimes

[Graham Smith]

Sight the 69 gr and the 77 gr loads at 175 yards instead of 100 yard sight in and the drop is fixed my 77 load drop rite in the Razor's Reticle lines so each distance out to 700yards match up with in 1" or so in stead of with in 1 moa.

Bravo. You can use the calculators at JBM Ballistics to play with velocity and zero and find something that works fairly well with a particular BDC a lot easier than trying to remember that the 300yd marker is really 260yds with your load.

[outerlimits]

I wonder if such an idea would work for other reticles and custom loads (Burris XTR in my case). I'm a little math stoopid sometimes

Close, but not good enuf. You really need a FFP scope to pull it off.

[Corey]

I wonder if such an idea would work for other reticles and custom loads (Burris XTR in my case). I'm a little math stoopid sometimes

Close, but not good enuf. You really need a FFP scope to pull it off.

Would it work on SFP scopes as long as they are cranked to max power? (which for long shots I do)

[outerlimits]

I wonder if such an idea would work for other reticles and custom loads (Burris XTR in my case). I'm a little math stoopid sometimes

Close, but not good enuf. You really need a FFP scope to pull it off.

Would it work on SFP scopes as long as they are cranked to max power? (which for long shots I do)

yep-but you have to prove it at the range. basic process is this. first, find your most accurate load(s). get the chrono out once you have that and get that data. sit in front of yer computer and feed the data into the JBM calculator. plug in the manufacturers specs on their reticle into JBM and compare. start playing around with different zero's until you can map out the ballistics for your load(s) to be as close as possible to that of the reticle ballistics. then, head to the range for a boring but necessary set of trials to prove what JBM is telling you. you might find certain ranges to be more accurate than others. for example, maybe the mapping is "true" from say 200-350, but goes out the window after that. that's where the price of the scope starts to matter. in other words, you start to find out how accurate the BDC is for your scope. YMMV, but it is a true formula...but you have to prove it out at the range.

[Corey]

I wonder if such an idea would work for other reticles and custom loads (Burris XTR in my case). I'm a little math stoopid sometimes

Close, but not good enuf. You really need a FFP scope to pull it off.

Would it work on SFP scopes as long as they are cranked to max power? (which for long shots I do)

yep-but you have to prove it at the range. basic process is this. first, find your most accurate load(s). get the chrono out once you have that and get that data. sit in front of yer computer and feed the data into the JBM calculator. plug in the manufacturers specs on their reticle into JBM and compare. start playing around with different zero's until you can map out the ballistics for your load(s) to be as close as possible to that of the reticle ballistics. then, head to the range for a boring but necessary set of trials to prove what JBM is telling you. you might find certain ranges to be more accurate than others. for example, maybe the mapping is "true" from say 200-350, but goes out the window after that. that's where the price of the scope starts to matter. in other words, you start to find out how accurate the BDC is for your scope. YMMV, but it is a true formula...but you have to prove it out at the range.

thanks.

Step one is this weekend. Got a bunch of rounds to test for accuracy. And you're right...all is well and good on paper, but its what actually happens on the range that counts.

[DocMedic]

This is why I only shoot one grain of bullet. with XM193 at the first Tick mark (4.4moa) I get Approx 350 yards, and at second tick (8.0moa) I Get Approx 450 yards. 100yard zero, at 4850 ft above sea level.

Edit: Well went to the range again today to play with zero's a bit before SMM3g, So I settled on a 200yard zero. So now my first tick (4.4moa) is a 1moa from 400 yards. and 8.0moa will give me 490yards

Edited March 16, 2011 by DocMedic

[AlamoShooter]

I wonder if such an idea would work for other reticles and custom loads (Burris XTR in my case). I'm a little math stoopid sometimes

Close, but not good enuf. You really need a FFP scope to pull it off.

Would it work on SFP scopes as long as they are cranked to max power? (which for long shots I do)

yep-but you have to prove it at the range. basic process is this. first, find your most accurate load(s). get the chrono out once you have that and get that data. sit in front of yer computer and feed the data into the JBM calculator. plug in the manufacturers specs on their reticle into JBM and compare. start playing around with different zero's until you can map out the ballistics for your load(s) to be as close as possible to that of the reticle ballistics. then, head to the range for a boring but necessary set of trials to prove what JBM is telling you. you might find certain ranges to be more accurate than others. for example, maybe the mapping is "true" from say 200-350, but goes out the window after that. that's where the price of the scope starts to matter. in other words, you start to find out how accurate the BDC is for your scope. YMMV, but it is a true formula...but you have to prove it out at the range.

thanks.

Step one is this weekend. Got a bunch of rounds to test for accuracy. And you're right...all is well and good on paper, but its what actually happens on the range that counts.

Outer-Limits has it explained better that I did , The only difference is I would trust the math in the Ballistic calculator more than just one or two trials in the field.

make sure you get your Geographic Elevation entered on the Ballistic Calculator too. a change of 4000 feet will make a full minute difference at 500 yards

knowing the ballistic coefficient is necessary too to get good # in for Good ##S out