Checking your deer rifle

[Kwaynem]

Question for you guys that shoot a lot I was thinking about checking my zero on my 6.5 creedmoor this weekend while I’m off for rifle season it’s supposed to be in the 70’s say I have it where I want it and rifle season gets here and it’s say in the 30’s in the mornings will my POI change?

 

[JEVapa]

Not enough to miss unless you're shooting 800m-1000m. Then maybe.

 

[rockchalk06]

Yes. No.

If you zero'd it at say 90° and have a 20° drop, it might change. I assume you were using H4350? Probably not, but you will want to know. 90° to 30° you will see a drop in velocity that will affect POI. How much inside 200 yards will be small but there will be a change. Every rifle is different. That's why its a good idear to run your load over a chrono and see what the velocity is. I'm a nerd, so I get it speeds at every temp I can.

***Edited to add*** Only way to tell for sure is to shoot it and see. Unless you are trying to kill a deer at speeds your bullet will NOT humanely kill a deer, I don't think you will be able to tell.

My rifles sit in the safe cleaned. When I get the chance to hunt, I always throw my can on and check zero. Most of the time the change is so small you'd need a caliper to measure the chance. Foul the bore and get ready for season. I won't touch it unless we have a major temp change. Rinse and repeat.

 

[Kwaynem]

I do use H4350 on the 140’s and the 129’s I don’t worry about dope i usually sight in 2”s high at 100 yards then don’t worry about it shooting at a deer 200 yards or less if I want to shoot at 300 I use the next line below the center crosshairs but when checking zero it drives me crazy if it’s not perfect at 100

 

[JEVapa]

I zero POA/POI at 100m then use holds. I've found that shooting high 1-2" at 100 is never really accurate; it's not the same for all cartridges but people treat as the same for all cartridges. You'll have more error from that than some change in temperature going into the wintertime.

 

[Kwaynem]

I zero POA/POI at 100m then use holds. I've found that shooting high 1-2" at 100 is never really accurate; it's not the same for all cartridges but people treat as the same for all cartridges. You'll have more error from that than some change in temperature going into the wintertime.

Hasn’t failed me hunting yet in over 40 years I think I’ll stick with it

 

[JCann]

If you had a Kestrel that corrected for density altitude (DA) or pressure altitude, this wouldn’t really be an issue.

Zeroing a rifle at sea level with 100 degree/humidity and then going on a sheep hunt at 8000 ft elevation and 20 degree/humidity factors different DA.

A Kestrel with a weather meter will compute a firing solution in these situations correcting for density. But, a responsible hunter should always verify zero whenever possible.

 

[JEVapa]

Hasn’t failed me hunting yet in over 40 years I think I’ll stick with it

Exactly my point. Your temperature concern isn’t an issue.

We can probably lock this thread up, problem solved.

 

[KurtM]

All this reminds me of a statement Col. Cooper once made. "This is a preoccupation with inconsequential increments".

The "sweet spot" on a deer is about 10"....maybe 8" on these little whitetails. At 200 yards your rifle would have to be off 4-5 MOA due to a temp shift before you would be tracking instead of dressing. Notice I didn't say "don't check your zero" but If I zeroed it in the warmth, I wouldn't worry about it.

 

[Kwaynem]

Exactly my point. Your temperature concern isn’t an issue.

We can probably lock this thread up, problem solved.

I think your missing the question will temperature change from hot to cold affect POI

 

[JEVapa]

Back to my original answer. Not enough to matter almost any deer hunting range. From 70f to 30f ? Nah

 

[KurtM]

Yes, the temp will affect you POI. How much will depend on the powder you use and how temperature sensitive it is, the primer you use and how much your barrel changes due to the temperature change. So the answer to your original question is YES.
There are a couple of ways to deal with that information. One way is to go shoot groups during all weather events, from hot to cold in 10° increments. In rain, humidity, dryness, snow, that you would expect during your hunt. Don't forget if you plan to travel to shoot groups at all elevations in all conditions as well. Log it all carefully and at the end you will have definitive information....except you will now need a new barrel and you will have to start all over again, BUT....the short answer which I think you wanted is. YES you POI will change. Will that matter? That's up to you.

 

[AER244]

For the last 4 years I’ve been shooting a 300wm mainly. Yes it’s overkill. Blow me. I usually check my zero first in August for antelope, again in November for deer, then again in January for antelope again. All outside. My POI is all within the margin of error of what I’m likely capable of, 3/4”ish inches. Last year the difference between August and January temps was 103 degrees. The POI, without adjustment, from Aug-Jan was nearly identical. I personally wouldn’t fret over it much if all others factors remain somewhat equal. I also don’t shoot much past 400yds. YMMV