How much does your rifle's point of impact change when you travel?

[Len Backus]

How much does your rifle's point of impact change when you travel?

And do you routinely check your zero if you travel to a hunting spot?

 

[RDM416]

It depends on the type of travel. If I am going by plane or if my rifle is being transported by someone else I will check the zero. Most of the time I drive on hunting trips and my rifle is carefully handled and in a "Storm" case. I normally will not check the zero if the gun has not been out of my hands.

I have never noticed any POI changes (at 100 yards) from changes of climate and elevation when traveling from east to west. I do however rely on my ballistics program to supply the proper dial up data based on location and environmental conditions where I am hunting.

 

[WildRose]

I've never really noticed any significant difference unless I changed elevation by more than about 3,000-4,000ft as long as I have quality optics.

I do think however it's only responsible to at least check zero when arriving at a new destination if at all possible, because rattling and jarring can have an effect on your equipment.

 

[FAL Shot]

You need to reset a zero if your elevation changes by 1000 feet and your ambient temperature by 20 degrees Fahrenheit, especially at long range. Would not be a factor in short range brush hunting.

Heat mirage is a major factor around here on the prairie, but nothing to do with rifle, scope or ammo. I just aim a bit lower when I detect heat mirage.

Powder sensitivity to temperature is a consideration, as well as primer sensitivity to temp change. People rarely consider this when working up a load for the smallest groups at the rifle range. Word on the street was that Winchester primers had the least sensitivity to temp change, so I bought thousands of them way back and am still shooting off them, except for some recent CCI magnum primers. Military powders seem rather stable with temp changes, in general.

If powder and primer are changing with temp, you don't have an issue with rifle/scope point of impact changing. Only time I had an issue with my rifle changing point of impact was when I had a failing scope.

I learned the hard way that what shoots great at one temp might not do the same at a different temp. It's not a rifle issue but an ammo issue. I live in a continental climate with wide seasonal temp changes, not such a big deal if you are coastal.

 

[Len Backus]

You need to reset a zero if your elevation changes by 1000 feet

I didn't make my question clear enough, sorry. I wasn't talking about atmospheric reasons for a different POI at longer distances.

I meant how much does your 100 yd zero change?

 

[squirrelduster]

I live on the north coast of California and recently went to Wyoming on an antelope hunt. My zero changed due to elevation changes.
I am making it standard practice to always shoot when I arrive. Check zero and check again at 400 or so to verify everything is as it should be. I missed my antelope at 630 because of the elevation change in Wyoming. Ended up shooting him but is was 4 miles farther from the truck.

 

[Coyboy]

If the conditions from one spot to another are similar I would suspect zero change.

Problem is we usually go to elevation, I always reshoot and 7 out of tem times reset my turret. My process is to reshoot my 200 yard zero reset if need be. Then check my dope cards at from 600-900 yards. depending on how that goes I may once again reset my turret so the error is minimized at the longer ranges. I usually always have a hand held balistic calculator but often times don't use it in a hunting condition where time may be an issue.

Now to adress the "traveling caused" zero change. I am always careful to pack the rifles so they are not put under undue pressure. I have seen guys throw there guns on a duffle bag and then throw more stuff on top. Think of what 1200 miles of uneven pressure bouncing up and down on your rifle could do to it's zero.
hard cases may minimize this but soft cases offer little protection from this.

What about your ammo. I have a fellow f-class shooter who was using .0015" neck tension on a compressed load, packed his ammo on a hard surface of the vehicle and the bouncing and jiggling caused some of the bullets to push out and change his seating depth up to .020". He shot like crap but learned a valuable lesson.

 

[Len Backus]

I never would have thought of the ammo. Great point.