cold weather load testing

[RW]

when testing loads in cold weather for instance in the teens will this change how a load will perform in warmer weather? I'm not talking about higher pressures in warmer weather but if the dynamics such as barrel harmonics changing in the cold weather as apposed to warmer temps affecting accuracy, Thanks you, RW

 

[Dusty Stevens]

Yes. Cold air is denser and the powder burns hotter in warmer weather so it is miles away using a cold weather load in the summer.

 

[RW]

Yes. Cold air is denser and the powder burns hotter in warmer weather so it is miles away using a cold weather load in the summer.

yes Iunderstsnd the problems I


tamp, but how much doesbinnnig as far as cold being from cvold

 

[spclark]

yes Iunderstsnd the problems I


tamp, but how much doesbinnnig as far as cold being from cvold

Please translate that statement once your fingers warm up & you can key it in w/o shivering....

Being cold changes things, performance-wise. Being COLD when it's supposed to be fun? Not worth it to my mind.

 

[dedogs]

Please translate that statement once your fingers warm up & you can key it in w/o shivering....

Being cold changes things, performance-wise. Being COLD when it's supposed to be fun? Not worth it to my mind.

???? +1 on translation. dedogs

 

[MGYSGT]

The air is denser, so that changes things a smigen. I suppose a barrel in the teens would be affected, but probably only for the first few shots until the barrel warms up.

 

[LoganDon]

The air is denser, so that changes things a smigen. I suppose a barrel in the teens would be affected, but probably only for the first few shots until the barrel warms up.

As a range officer in N. Utah, I shot my custom 257AI at -6F last week and got 2" groups at 200 yds with my summer load. I usually get +/- 1" groups with this rifle and load at 200. I have found mag primers seem to be needed in extreme cold. My 7x57 is reacting the same way; however, my 6ppc seems to do fine.

 

[Jason Boersma]

I don't work up a load for a match rifle until it gets to atleast 50 degrees out but with hunting and varmint rifles I have shot great at 100 and 200 when it was so cold I couldn't feel my fingers.

 

[normmatzen]

Where I shoot, it can get much hotter later in the day as well as damn cold in the winter. As a general practice, I bring my room temp loads to the range in an insulated bag and only take out enough ammo for the current relay. The loads do not change temp very quickly and I don't chamber them till just prior to shooting.

 

[dkhunt14]

I agree a lot with what Tom says. I don't shoot my match rifles when it is cold. I shoot my hunting guns when it is below 40 because that is what I am usually hunting in. Last year one morning it was around zero. I picked out a rock at 1370 yards. I put the clicks on the scope and shot. It was right there for elevation. Later in the day when it warmed up to close to 40 I shot again. The gun sat there with the same clicks and aimed on the same rock. The second shot was also right there. Now that was with a 338 Lapua IMP. with Re33 and a 300 Berger. Some guns and powders are better at that then some others. You need to test and see what your gun does. As far as accuracy goes I don't see a great amount of change in my hunting guns for group size. I never shoot my match guns in the cold because I want to shoot under the same conditions matches are shot in. I know I might encounter 30 degrees or difference between the beginning of the year and the end. My 300 WSM doesn't seem to change that much in group size or the amount of powder I need under those circumstances. Matt

 

[dkhunt14]

I actually will be going out in afternoons, hopefully above 20-25 here in the next month. The things I can learn during these winter days about my match rifles.... powder,primer, bullet combination the barrel might like. I can also do some initial seating depth testing. Most importantly,I can get some rounds on it, so come late February and early March I can get serious about tuning. These would be fresh barrels of course, the ones with a season on them there is really no need. Of course in my situation,this means I will be very busy busting open a trail in the damn snow.

Tom

You guys get to shoot in a lot colder temps then we do. We very seldom shoot below 70 degrees or above 90. We don't start till May and unless a cold front is here it is usually above 70. Matt

 

[memilanuk]

You guys get to shoot in a lot colder temps then we do. We very seldom shoot below 70 degrees or above 90. We don't start till May and unless a cold front is here it is usually above 70. Matt

Our match dates start a little earlier and our tolerance for cool weather is a little more, at least around here (PNW). That said, a lot of people do load development during the off-season. One of the 'problems' for me is the BSWN match - in early February. Here, its a snow-covered 20-30F, there... well last year I got a sun-burn and had the AC running in the car and in my hotel room

 

[4xforfun]

It doesn't make a lick of difference if you do it correctly.

First, for summer loads in the winter..keep your test ammo warm.....I keep mine in the running truck. 75 degree ammo is 75 degree ammo......winter or summer. I only take a couple out at a time. If I am running 5 shot groups I will pull 5 from the truck and keep them in an inside pocket untill I am ready to shoot. Take them directly from your pocket to the load port to a closed bolt in a very short time.

Keep your gun warm....ie....keep shooting. I start with a warm gun that has been sitting in a warm truck. Have EVERYTHING all set up and ready to go before you get your gun. Then...keep shooting. The heat from your BBL will migrate to your chamber. The gun will stay warm...your loads will think it is summer.

Group size will not change. Group location may change a little....cold air is denser...bullets slow down faster, so at extended ranges your group will print a little lower......but group SHAPE AND SIZE will be the same.

All this bbl harmonics talk is pure bull....every time you shoot your gun...summer or winter, your bbl heats and cools. If temp causes adverse BBL harmonics, wouldn't you see the issues in the summer , also??? You BBL gets hot. Your BBL gets cool.

Air density...bull. Air density is a factor in EXTERIOR BALISTICS. Once the bullet leaves the BBL, it becomes a factor, but only so far as velocity degradation. Group shape and size will remain constant......just print high or low.

If you are working up loads for winter use , keep you ammo cold. let it sit on the bench and cool off. Don't let your rounds cook in the chamber. Load em and shootem.....cold.

Tod