jaginger
Member
At -40 degrees, they are precisely the same: -40C = -40FThanks, that helps!
Now I realize that there's basically no difference between Celsius and Fahrenheit. -42 to -44
I’m always busy at the wrong time…for SCIENCE!!!😡🤣. Anyone ever shoot at these temps and get chrono numbers?
- Thread starter Calvin45
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we are supposed to hit 34 tomorrow in Houston. It is going to be 83 todayIt's cold in Tucson Az today. Gonna be 57.
TX mountain hunter
Well-Known Member
I would love to see this range of results even if it's by PM if you don't mind sharing.
Sembob
Member
At -40 they celsiu and Fahrenheit are the same.Thanks, that helps!
Now I realize that there's basically no difference between Celsius and Fahrenheit. -42 to -44
Interested to see your results. The coldest I've shot is 0F (-18C) and it took a few extra clicks with a second shot to get to 1000. The only time the kestrel has been wrong for me. I think it was because it was in my pocket just prior to use. Didn't get a chrono speed (battery died + didn't have a fresh one). Was so cold that I only shot a few times then hopped into the warm pickup a headed home. I did kill a buck at just over 1200 in 10F (-12C) weather. Remembered to leave the kestrel out for a few minutes prior to shooting and dope was right on. If I remember correctly it was a 2.5 MOA (10 more clicks) than shooting at 1200 in 80F (27C).
I have a serious questions about this.
Does the cold effect barrel harmonics? So if you strive for xyz fps for accuracy is that still a viable goal when your barrel is -20 to -40? Maybe a slower velocity actually is more accurate in an extremely cold barrel?
Also is there an accumulated degradation in gun powder performance as time at extreme temperatures continue. Say you are on a backpack hunt so it's not one day at negative xy degrees but multiple?
What about diurnal flux. Arctic village might not have a temperature change in winter because the sun never shines but in CO your powder could be changing 40 degrees or more every day. Does that have an accumulated effect??
Sorry to bring science back into the it was so cold stories but now I'm curious and I don't think any Korean War veterans I know we're doing studies back then.
Does the cold effect barrel harmonics? So if you strive for xyz fps for accuracy is that still a viable goal when your barrel is -20 to -40? Maybe a slower velocity actually is more accurate in an extremely cold barrel?
Also is there an accumulated degradation in gun powder performance as time at extreme temperatures continue. Say you are on a backpack hunt so it's not one day at negative xy degrees but multiple?
What about diurnal flux. Arctic village might not have a temperature change in winter because the sun never shines but in CO your powder could be changing 40 degrees or more every day. Does that have an accumulated effect??
Sorry to bring science back into the it was so cold stories but now I'm curious and I don't think any Korean War veterans I know we're doing studies back then.
Calvin45
Well-Known Member
Hey good questions. I don't know what the constant temp flux does to powder. I do know that I've done lots of hunting in November (usually between -10 c and -25 c) and this would involve getting out for hours and having my ammo get as cold as the air it was in, then coming home and bringing it in (I never l left it outside) and having warm up to room temp again, and then doing it again the next day (i take much shorter seasons now) and so on. Never had an issue, even growing up using dads ammo from the 70s that had no doubt been subjected to this treatment for years, possibly decades. He's one of those old fashioned farmer hunters for whom a box of ammo lasts 10 years or so. No issues.
Great questions! I was just thinking the same things!! Hopefully someone on here knows the answers. Bryan Litz we need you!!!
Footsie80
Active Member
FWIW, don't include windchill in any data you try to extrapolate from shooting in cold weather. Windchill only affects organic cellular matter. But, I realize you're mostly showcasing the beautiful Saskatchewan weather you're having. We're experiencing much of the same in the NWT, though it has warmed up to -32⁰ Celsius today
I haven't had time to do the testing I want to do. I have ran into trouble in the early 2000 or late 1998. I was working up a load for my 308 NM at the time. I had develop it in the last winter. So where around 50 to 65 degree area. Stop on that rifle and went to something else. Came back to it in early summer. Temp was somewhere around 90 to 100 degree. I don't remember what the velocity was at that time and day. I blow the primer out of my cartridge. I was getting a very consist 3400fps with a 165gr Nosler ballistic tip in the winter with that rifle. I hadn't realizes the IMR 4831, and IMR 4350 were so subject to temperature change. My load was IMR 4831 @ 75.8grs, Fed 215 primers, Win Brass, Case weight 238.5grs. 165gr Nosler B.Tip. Long story to short. I gave away the IMR Powders and never use them again. I changed to H powders. Presently using H4350 in my 308 NM rifle. I got better velocity with the Fed 210 primers and groups with a 26" barrel length. Now I have use that H4350 powders in weather in 100+ to -20 degree without any notable change in point of impact. Never ran test at the range. Hopefully I will this next year, if complete my move to Montana.
Calvin45
Well-Known Member
Yep windchill has nothing to do with this…but wait!!!!! More science questions from me now!!! As most on here have noted or experienced, cold air is much denser than hot air. Would this mean that at equal crosswind speeds bullets should experience more drift in cold weather because the air that's pushing them sideways is heavier and thus pushing harder even if the wind speed is the same? You'd think it'd have to. I've honestly never shot beyond 600 yards yet so not far enough to really study this stuff while ruling out human error.FWIW, don't include windchill in any data you try to extrapolate from shooting in cold weather. Windchill only affects organic cellular matter. But, I realize you're mostly showcasing the beautiful Saskatchewan weather you're having. We're experiencing much of the same in the NWT, though it has warmed up to -32⁰ Celsius today
jasent
Well-Known Member
Calvin45
Well-Known Member
Hahaha I think many of us have done this. I sure have. When I was new to loading i discovered how temp sensitive Rl22 really is! From now on I never do load development in winter…if it's safe in July it's safe whenever is my policy!
Footsie80
Active Member
According to an article I just looked at, cold weather does have a noticeable impact on windage - at least on bullets with a low BC. At 500 yards, the test projectile moved almost 7" more laterally at 0⁰ F then at 85⁰.
www.outdoorlife.com
How Cold Weather Can Kill Bullet Trajectory
The “cold-weather-effect” is real and can destroy your load’s accuracy. Here’s how to stay on target when the weather turns sour.
www.outdoorlife.com
