Hunting & Fishing Change of zero on hunting trip out west??

[buckey]

I am heading out west to Colorado in about 3 weeks for an elk hunt. I have my rifle zeroed & shooting well here in Pennsylvania.

How much will my zero change in Colorado with the higher elevations & thinner air??

Appreciate any info or help!!

 

[TF160 Guy]

Re: Change of zero on hunting trip out west??

This will depend on the elevation and the temperature at your destination.
The best solution is for you to shoot your weapon and confirm the zero. Regardless of the location after traveling strange things happen to sights, scope and guns.

Nothing spoils an expensive hunting trip faster than a missed shot that could have been prevented.

Good luck

 

[psinclair]

Re: Change of zero on hunting trip out west??

http://www.jbmballistics.com/index.shtml

Give this a look....

 

[med17]

Re: Change of zero on hunting trip out west??

Definetly get a good zero once you get there. There will be a difference between Pa. and Co. Good luck on your hunt!

 

[Greg Langelius *]

Re: Change of zero on hunting trip out west??

Always zero before the trip and recalibrate the zero on arrival.

Changes are inevitible. How much is immaterial, any change is significant. Many hunting shots are approximations, no POI deviation is your friend.

It's not just the new conditions, it can also be rough handling enroute. The baggage gorillas are not legends, they are fact.

Greg

 

[bohem]

Re: Change of zero on hunting trip out west??

The other MAJOR consideration is this:

Out to appx 350yd, the altitude won't make enough difference that you can correct it in a scope with 1/4MOA turrets, not even 1 click off your PA dope.

You recheck the zero due to travel considerations obviously, but your DOPE change past 350yd becomes a rapidly growing problem.

PGS' advice is spot on, run the JBM cards for changing altitudes (or more along my advice, run it for changing DA's around every 500') and keep multiple DOPE cards for you that are clearly marked for what DA you're shooting.

If you want a conversion chart to work from send me a PM and I'll hook you up for your specific load data.

 

[buckey]

Re: Change of zero on hunting trip out west??

bohem,

PM sent!!



Here's what my rifle is doing here in PA = 300 Win Mag, Barnes 180 grain TTSX at 3060fps.

100 yds:

 

[500grains]

Re: Change of zero on hunting trip out west??

If you zero on the east coast then head out west and your scope does not get bumped, your rounds will go high. So rezero out west.

 

[bohem]

Re: Change of zero on hunting trip out west??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 500grains</div><div class="ubbcode-body">If you zero on the east coast then head out west and your scope does not get bumped, your rounds will go high. So rezero out west. </div></div>

This is not really the case at common zero ranges the change in atmospheric conditions won't make enough of a difference that the scope can be adjusted to make up the difference, not even 1 click on a 1/4 MOA scope.

Now, by about 325-375yd this becomes a +/- 1 click zero change for a 308 shooting 175SMK's and with other rounds that have higher performance (BC and MV increases) then the range stretches out further than that before a functional change can be realized through scope adjustment.

You're right that setting a dope card at most places on the East Coast of the US will show impact changes at range in may places in the Rockies but this is not really much of a revelation as it's entirely possible to shoot at 1000-1500' DA and drive less than 2 hours on the same day and shoot at 4500'DA, and by 500yd the difference is significant enough to show up outside the vital zone on the average PA Whitetail.