Weather Conditions vs Shooting

[Phil3]

My shooting ranges can have temperatures ranging from 100+ to freezing, which got me to wondering, are there any things to consider when shooting in those temperature extremes? When it is hot, I can see overheated barrels and unfired rounds, as well as possible fatigue with the shooter. I am not sure with cold weather, other than me noticing it is harder to get comfortable and shoot with the extra bulk of warm clothing. I know differing conditions can also affect ballistics, but at my 100 yard range, this may not be much of an issue. What else comes into play when shooting in weather extremes?

Phil

 

[Terry]

Accurate powder charges can vary greatly. We will sometimes shoot winter club matches in WI. Some loads that were great at 30 were not at 80, others held up well.

 

[Lapua40X]

The term "preparing for weather conditions" means waiting until it's 75 degrees. ;D
Actually, it's probably a good idea to run test loads at various temperatures that you expect to compete in and note prevailing conditions such as muzzle velocity, temperature, humidity, altitude and barometric pressure. Not only for producing the best possible score, but for avoiding unnecessary and dangerous high pressures when the temp. rises.
Some of my filed ballistics data reveals that the .338 Lapua Magnum with a 250 grain bullet can vary in trajectory as much as 15 inches over 1000 yards when affected by an ambient air temperature variance of about 50 degrees. Competing in 40 degree temperatures could produce very disappointing results when the load was developed at 90 degrees.

 

[bheadboy]

i have shot br in the winter matches and the loads need to be changed to get the "same" accurcy of summer loads.

hunting winter i do my load workup confirmation in cool weather as some powders are more/less temp sensitive if shooting longer ranges.

bob

 

[Uthink Uknow]

It depends on what you are doing at 100 yards, Phil3. Any change in shooting conditions affects your accuracy or lack of. When you and all the other guys and gals are trying to shoot the smallest groups or hit the most 1/16th inch dots you need the most accurate load possible. This is why benchrest shooters use tuners and tune all the time or adjust their load to fit the condition.

 

[Phil3]

It sucks. My local range does have a 200 yard range..., on FRIDAY MORNINGS only. Weak. Anything beyond 200 is a 4 hour round trip. - Phil

 

[gotcha]

On cold winter mornings I always bring a little Crown Royal along. A few nips and the groups get smaller : Why adjust powder charges?

 

[Outrider27]

Some rifles respond oddly to extreme cold weather. I have a .223 Remington 700 BDL varmint special with the original factory stock that will print 5 shot 100 yard groups you can cover with a nickel all day long, even with me shooting it. At 50 to 85 degrees the POI is 1.25" high at 100 yards, the same as I sighted it in for in 1973. The few times I have shot it in extreme cold (14F to 18F) in the winter, the groups are the same size, but the POI is 1" below point of aim at 100 yards. I have a composite HS Precision stock for it sitting in the basement which should cure some or all of that, just haven't gotten around to swapping the barreled action into it. Maybe someday, before I make the swap, I'll pick a really old day and see if I can figure out what is changing in the cold to cause the POI shift.....

 

[22BRGUY]

Found this out today here in Minnesota. Had a sweet load for my .222 going, but today it was a little warmer than before....you know the rest of the story...back to the drawing board....but that's what keeps it all fun.