100m or 200m

kemsobe · #1 11-01-2010, 01:06 PM

Looking to see what you guys have for advice as far as what range i should sight my gun in at.

I've had good success with my .223 i bought a few yrs ago.
I shoot a 50 gr v-max at around 3200fps. and i have the scopes zero at 100m. Which has served me well for short shots on mostly coyotes, but i've been attempting a few longer range shots lately, and i was wondering if maybe i should adjust my scope to a 200m zero to help with poking out to the longer ranges. any advice? maybe some of you long range shooters can weigh in on this one, and definitely the coyote hunters here on AO!

Thanks for you're advice guys!

timsesink · #2 11-01-2010, 01:25 PM

What I look for in a coyote gun is knowing precisely where my bullet is going, so whether it's 100m or 200m it makes no real diffrence as long as I know exact drop at various distances. However for snap shots say in a 22-250 I would sight in @ 200yards which leaves you about an inch high at 100m and if I remeber correct -5 inches at 300. That would leave you with a MR of about 260m without adjusting holdover. After that it's time of some good range estimating as from spine to brisket a coyote is not real big. As as they say it's better to aim low then high as most guys shoot over then shoot under due to all the hair on the back.

lannie · #3 11-01-2010, 01:43 PM

good advice timsesink !

timsesink · #4 11-01-2010, 01:45 PM

well thankyou!

Tundra Monkey · #5 11-01-2010, 02:48 PM

I zero my quicker rifles at 300m (300winmag and a 257bee). Your gonna be in the kill zone with your 223 well past that on a dead centre hold. Just sayin'

tm

twofifty · #6 11-01-2010, 05:12 PM

kemsobe - plugging your 50gr V-max bullet data into an online ballistics calculator is a good way to approximate what would happen in the field for any given zero.

Here is the plotted trajectory with a 275 yard zero:

- bullet rises to 1st cross the line of sight at: 25yds.
- 3" high at 100 yds
- 3.7" high at 150 yds
- 3.3" at 200 yds
- 1.5" at 250 yds
- zero at 275 yds
- 1.9" low LOW at 300 yds
- 4.2" low at 325 yds
- 7" low at 350 yds
- 10.2" low at 375 yds
- 14" low at 400 yds.

With your cartridge, a 275 yard zero may be worth testing out with range and field experimentation.

If you have access to a 200 yard range, try sighting in 3.3" high at 200. From a perfectly steady rest on a calm day, aim for the bullseye and adjust the scope so the group centre moves to 3.3" high.

Note this data is for a 70F day, at 4000' above sea level, nil wind, with the target at a zero angular elevation.
ymmv

edit: changed data for 4000' above sea level

kemsobe · #7 11-01-2010, 11:07 PM

Quote:

Originally Posted by twofifty

kemsobe - plugging your 50gr V-max bullet data into an online ballistics calculator is a good way to approximate what would happen in the field for any given zero.

Here is the plotted trajectory with a 275 yard zero:

- bullet rises to 1st cross the line of sight at: 25yds.
- 3" high at 100 yds
- 3.7" high at 150 yds
- 3.3" at 200 yds
- 1.5" at 250 yds
- zero at 275 yds
- 1.9" low LOW at 300 yds
- 4.2" low at 325 yds
- 7" low at 350 yds
- 10.2" low at 375 yds
- 14" low at 400 yds.

With your cartridge, a 275 yard zero may be worth testing out with range and field experimentation.

If you have access to a 200 yard range, try sighting in 3.3" high at 200. From a perfectly steady rest on a calm day, aim for the bullseye and adjust the scope so the group centre moves to 3.3" high.

Note this data is for a 70F day, at 4000' above sea level, nil wind, with the target at a zero angular elevation.
ymmv

edit: changed data for 4000' above sea level

Where is it that you compute data like that? this information's is much appreciated, thanks a bunch for taking the time to figure those numbers for me! i think ill take ur advice and zero at about 3 inches high at 200m.. sorry that what my range has :P not yrds

twofifty · #8 11-02-2010, 12:41 AM

Google 'online ballistic calculator' and the first thing that
comes up is JBM Ballistics:

http://www.jbmballistics.com/

You can set the distance interval increments to whatever you want, in yards or meters. According to Hornady's website, the 50gr V-max has a ballistic coefficient of 0.242

Please confirm the data at the range before taking shots on animals. ymmv.
Then let us know how it works out for you. Have fun!

Cal · #9 11-02-2010, 11:09 AM

I sight my hunting rifles 3" high @ 100 but IMO thats too much for a varmint rifle. The bullet being almost 4" high at maximum rise is not a big deal with large game but on a gopher or even a coyote your getting to the point where youre going to be thinking about holding under medium ranges just so you can have less hold over at longer ranges, dumb tradeoff IMO. I like timesinks advice with the maximum rise being 1- 1 1/2" better.

twofifty · #10 11-02-2010, 05:13 PM

Cal I hear what you're saying and it makes perfect sense:

- sight in to MPBR (maximum point blank range) so as to entirely do away with 'holdover';
- keep the same critter-specific point of aim all the way out to where the bullet drops out of the MPBR's critter-specific vertical window.

My thinking - in this case with a 275yd zero- is to maximize MPBR so that if the gopher is near the trajectory's high point of 3.7" above line of sight at 150yds, then the shooter need only hold on the lower third of the critter's body.

It works this way:
- Place the reticle 2" or 3" below centre and let her rip.
- Your reticle is still on fur, not in the grass, so you know exactly where you are and where your bullet will go (given that day's conditions).
- No need for a 'fancy' reticle with elevation holdover hashmarks.

Cal · #11 11-02-2010, 05:37 PM

I understand what MPBR does, but in going with such a far zero you are replacing a small hold over at 300 yards with a small hold under at 150, to me that makes no sense. Just looking at my lab as I write this I would say he has about a 5-6" diameter kill zon. Assuming a coyote's kill zone is similar going with a zero that only puts me 1-2" high max I could hold the crosshairs level with his back and still put the bullet in his kill zone at 300 yards rather than holding low at 150, which seems more logical to me.

Littlejet · #12 11-02-2010, 06:29 PM

Quote:

Originally Posted by twofifty

Google 'online ballistic calculator' and the first thing that
comes up is JBM Ballistics:

http://www.jbmballistics.com/

You can set the distance interval increments to whatever you want, in yards or meters. According to Hornady's website, the 50gr V-max has a ballistic coefficient of 0.242

Please confirm the data at the range before taking shots on animals. ymmv.
Then let us know how it works out for you. Have fun!

Thats a great Tool

I use it for all my guns.

catnthehat · #13 11-03-2010, 06:59 AM

Quote:

Originally Posted by kemsobe

Looking to see what you guys have for advice as far as what range i should sight my gun in at.

I've had good success with my .223 i bought a few yrs ago.
I shoot a 50 gr v-max at around 3200fps. and i have the scopes zero at 100m. Which has served me well for short shots on mostly coyotes, but i've been attempting a few longer range shots lately, and i was wondering if maybe i should adjust my scope to a 200m zero to help with poking out to the longer ranges. any advice? maybe some of you long range shooters can weigh in on this one, and definitely the coyote hunters here on AO!

Thanks for you're advice guys!

My walking varminters in 222 and .223 have been zeroed at 200 meters for the last 30 years.
Cat

timsesink · #14 11-03-2010, 09:16 AM

4 inches high is WAY to high for varmints. A good rifleman needs to be able to know where that bullet is all the time not in some fuzzy 6inch area especially on something like a coyote. 200yards is perfect in my opinion. Best of both worlds.