To hot to sight in?
- Thread starter Moparnut
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rcmodel
Member in memoriam
High temperature will raise pressure & velocity when it's 100+, which in turn will change zero next winter when its 70 or 80 degrees colder.
Probably not enough to miss a deer, but certainly enough to miss a ground squirrel or whatever you have as small targets in Arkansas.
But you have no choice but to sight in now if you want to use the rifle for the next few months and get in some pre-season practice.
If you want to hunt deer in the fall, check zero again in more seasonal weather.
It's good familiarization with the rifle just before hunting season, and more great practice anyway.
rc
Probably not enough to miss a deer, but certainly enough to miss a ground squirrel or whatever you have as small targets in Arkansas.
But you have no choice but to sight in now if you want to use the rifle for the next few months and get in some pre-season practice.
If you want to hunt deer in the fall, check zero again in more seasonal weather.
It's good familiarization with the rifle just before hunting season, and more great practice anyway.
rc
TurtlePhish
Member
That depends a lot on the stock material. If it's good synthetic, temp/humidity changes will only have a small effect, if any. However, if it's wood, the same change in temp/humidity could have a pretty big effect on zero. If you're worried about the barrel being heated by the air, it's probably not gonna get hot enough to change POI. Maybe if it's black and in the sun, but I don't have any firsthand experience with that. My range is covered outdoors, and I haven't seen any POI change with temp changes.
Ar180shooter
Member
Certain powders such a Varget are very consistent in different temperatures.
rcmodel
Member in memoriam
Thats great if you know of any commercial manufacture who uses Varget powder, or use it yourself.
But I take it the OP is not a reloader.
rc
But I take it the OP is not a reloader.
rc
jim147
Member
With the current 100°+ temps, don't forget about mirage off the barrel and at the target.
Use your current shooting time as practice to see what it is really doing when the temps change. You may be fine or your rifle may move a lot.
jim
Use your current shooting time as practice to see what it is really doing when the temps change. You may be fine or your rifle may move a lot.
jim
It's more like, how long does your ammo sit in the sun to throw off it's point of impact. Most of my ammo is stored at about 74 degrees year round. Sighting in is done when it is between 65 and 80 degrees outside. Ammo is never left out in the sun and stays dry and covered. Yes, I will sight in during a light rain, not sure how the rain drops effect my accuracy, but it is done under a covered bench.
Some powders are more temp sensitive than others, but it is always smart to check your zero before going out on a hunt. More problems are caused by the scope being bounced around than by the temp of the ammo. Most of my ammo is at body temperature during a hunt and will only change when placed in the gun.
Will the POI change if it is -10 degrees or +100 outside, yes, but then I have no control over the weather, just the settings on my scopes.
Jim
Reloadron
Contributing Member
I've known BR match shooters who went so far as keeping their ammunition in a cooler at the range. They figured regardless of the actual ammunition temperature it was consistent. How much does it really matter between 100 degree F ammunition and 20 degree ammunition? I never worried about it. Not for hunting or everyday shooting anyway.
Ron
Ron
redneck2
Member
The biggest effect can be how long the barrel cools, when the round is chambered, and how long the new round sits in the chamber before firing.
If you have a higher velocity rifle (22-250), the chamber pressure (velocity) is typically higher because it generates more heat. If you shoot, immediately chamber a new round, then let it sit, the powder absorbs heat thru the brass.
Obviously as ambient temperatures increase, the barrel cools more slowly.
If it's a hotter day, I try to let the rifle sit at least thirty seconds with the bolt open and the muzzle pointed up to let air thru. With my .204 during colder weather it takes quite a few shots to get the barrel warm. If it's 80 or higher, it will get warm in maybe five shots.
The British had problems with the first smokeless rounds in Africa and India due to heat/pressure.
If you have a higher velocity rifle (22-250), the chamber pressure (velocity) is typically higher because it generates more heat. If you shoot, immediately chamber a new round, then let it sit, the powder absorbs heat thru the brass.
Obviously as ambient temperatures increase, the barrel cools more slowly.
If it's a hotter day, I try to let the rifle sit at least thirty seconds with the bolt open and the muzzle pointed up to let air thru. With my .204 during colder weather it takes quite a few shots to get the barrel warm. If it's 80 or higher, it will get warm in maybe five shots.
The British had problems with the first smokeless rounds in Africa and India due to heat/pressure.
W.E.G.
Member
"Its too hot!" is no excuse for not going to the range.
Put on your hat, and some light-colored clothes. Pick up some Gatorade and water, and quit complaining.
Test your gear in a variety of conditions. The answer is not on the internet.
Put on your hat, and some light-colored clothes. Pick up some Gatorade and water, and quit complaining.
Test your gear in a variety of conditions. The answer is not on the internet.
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