Range Report Check my dope...

[Josh-L]

Went out and sighted my new Rem 700 in 223 in today and didn't have much time so I just got quick and rough dope from 100 - 600. Shooting 75 grainers at an avg of 2765 I came up with...

200 = 1.5 moa
300 = 4.5 moa
400 = 9 moa
500 = 12.5 moa
600 = 20.5 moa

The 200 and 300 match just about perfect with a few programs I've tried but the 4/5/600 are pretty far off. KAC bullet flight on my iPhone was way off as well. Anyone have a similar setup they can compare their numbers too?

 

[xNF_9]

Re: Check my dope...

knowing the weather helps a lot too

 

[sobrbiker883]

Re: Check my dope...

Your dope matches 2650 better than 2765, if your DA is anywhere around 2K.

How did you come up with your speed? 200/300 isn't going to be far off if you shoot 2500 or 2800 with the same bullets....

 

[Josh-L]

Re: Check my dope...

I didnt have much time so I just avg six shots to get the speed.

Here is what I'm inputting...

BC = 0.395 (not sure if that's quite right. I got that from Hornadys website)

Bullet weight = 75 grain

Muzzle Velocity = 2765

Sight Height = 1.85

Barometric Pressure = 29.75

Altitude = 1200

Relative Humidity = 70%

Temp = 65

 

[sobrbiker883]

Re: Check my dope...

Actually your 600 seems to be way more than needed even at 2650fps. Your dope at 500 and in matches my 2650 dope, but even at that you should be only around 17moa at 600yds.

What scope and have you checked its tracking (what adjustment you actually get-dialing 20 moa get you ~21" of movement at 100yds?

 

[Josh-L]

Re: Check my dope...

It's a Leupold Mk 4 3.5-10 with M2 knobs. I didn't check the movement. After I shot 600 I dialed it back down to 0 and went back to 100 and it was were it should be so I would think it was tracking ok. Could the side focus not being right cause that much change?

 

[gvanhyning]

Re: Check my dope...

Here are some considerations. What is the size of your scope objective lens? Looking at the scope height that you gave, 1.85" seems low unless it's a 40mm objective. Correct scope height is a factor. Is the scope FFP? If it's second focal plane POI may shift with magnification.

 

[Josh-L]

Re: Check my dope...

40mm objective. It's in TPS low rings. I just used a tape measure and guessed it was about 1.85 inches. It's second focal plane and I shot it all day on 10x. Just can't figure out why I needed so much more elevation at 600.

 

[gvanhyning]

Re: Check my dope...

I ran your numbers using the JBM model and your numbers started going south at 400 hundred by about 1.5 MOA and at 600 by 5 MOA. I did not try those numbers with different drag models but used G1. Try the JBM calculator see what you get. Good luck.

 

[Tunin]

Re: Check my dope...

Yes, your "side focus" is not so much focus as it is also a parallax adjustment. Before each shot at a new distance do this: with rifle steady, bob head up and down about one-two millimeters (i.e. not much), your cross hairs should stay rock solid on your target's center. You'll find that there is a difference between your 100 yd shots and at least your 300 yd shots. There's not a ton of difference for first several hundred yards, but by the time you're out to 600 yds the difference in crosshair movement (parallax) is considerable, i.e. very slight differences in how you hold your eye relative to your scope will make large differences downrange.

 

[dar1246]

Re: Check my dope...

When checking your dope. You should always know the weather conditions. This will help you during shooting sessions.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: N0S</div><div class="ubbcode-body">knowing the weather helps a lot too </div></div>