Worth working up loads in cold weather?

[Viperdoc]

I have been trying to work up loads for my 223 AR with a 7.7 twist Krieger as well as a 6.5 CM, but of course it is now 20 degrees here in Wisconsin. I have found some promising nodes, but am questioning how valuable this data will be come summer? I did see nearly a 200 fps difference with R 17 from some loads chronoed at 80 versus 36 degrees. This suggests that any loads worked up in cold weather might be drastically different this summer. The ammo was kept at RT in plastic boxes un til used, but I'm sure they cool to ambient pretty quickly. Is working up loads in wintertime sort of a waste?

 

[4xforfun]

Here is what I did, because I have my own range. I park my truck right next to my bench. I keep the gun and ammo in the truck, keeping them warm. I just simply set everything up, and keep the ammo and gun in the in truck till I shoot. After I get set up I leave the gun in the rest. It is not the temp of the gun, it is the temp of the ammo. BUT....... I keep the gun fairly warmed up by shooting. Don't let it get to hot or cold. And, just like in the summer, don't let a round cook/freeze in the chamber. This WILL affect velocity to some degree.

Another heads up.....park the car/truck on the down wind side of the bench, or behind it........the heat created by the running engin creates mirage!!

Hope this helps.

Also, I posted the same question on BR Centeral in long range forms......look it up.

 

[CJ6]

If your going to use these loads in winter by all means this is when you need to work them up, but if your looking at useing them in summer heat ...then your wasteing time ,componants. I have separate Winter/Summer loads.

 

[dreever]

A lot depends on the type of powder and how close to max you intend to push things. Myself I've found Varget pretty forgiving as far as temperature goes and since my loads are not pushing the ragged edge they work for me regardless if it is thirty degrees or ninety. I worked up loads for my .308 when it was 85 degrees and checked them on paper out to 840 yards the begining of November at 30 degrees. My sight settings were exactly the same and groups remained consistant.
In my .223's I like to use AA 2520 because it goes thru the powder measure like water. However it IS temperature sensitive so I'd be concerned about loads I worked up in thirty degree weather when it was pushing ninety degrees so with the 2520 I worked up loads in the heat of the summer.
The military doesn't have seperate winter/summer loads (with perhaps the exception of artic warfare loads) so use a load that will work in all temperatures.

Danny

 

[4xforfun]

If your going to use these loads in winter by all means this is when you need to work them up, but if your looking at useing them in summer heat ...then your wasteing time ,componants. I have separate Winter/Summer loads.

I will agree with part of that...if you are going to use the loads in the winter/cold then test in winter/cold, without trying to keep things warm. Cold guns/ammo act differant than warm guns/ammo. On the other hand, if you keep your bbl/chamber and your ammo at summer temps..you are NOT wasting your time. Temp/exterior balistics have no bearing on rifle/ammo tune. NONE. Your powder/ load does not care what season it is...only what temp they are at when things go BANG.

 

[Viperdoc]

I guess my main question is that most of my target and varmint loads will be used in the summer, but I want to continue load development and shooting all year (as tolerated). However, it seems like a good load developed in the winter may be way off in the summer, unless I can find a way to keep the ammo fairly warm for winter testing. Maybe some hand warmers placed in an insulated ammo can would be useful?

 

[ReedG]

Viperdoc, my experience with Hodgdon Extreme powders is that you can do load development in any weather you can reasonably stand, say down to 20F, and use the loads in the heat of summer just fine. If you find a good load with Varget, Benchmark, H4198, etc., at most it will need a .1 to .2 tweak in the hot weather but a good load in cold is still a good load in heat.

 

[4xforfun]

Viperdoc, my experience with Hodgdon Extreme powders is that you can do load development in any weather you can reasonably stand, say down to 20F, and use the loads in the heat of summer just fine. If you find a good load with Varget, Benchmark, H4198, etc., at most it will need a .1 to .2 tweak in the hot weather but a good load in cold is still a good load in heat.

I think you have that backwards......a good load in hot temps will work in cold, but a good load in cold may well lock up your gun in hot weather!!!! I don't care what kind of powder you use. Most guys load to the edge, which could be friggen dangerous when shot in hot temps.

 

[RonAKA]

If you trust your chronograph, you are not wasting your time. I believe nodes are defined by the velocity, so as long as you can duplicate that same velocity in summer you should be fine.

That said shooting in cold weather can be a pain, especially with temperature sensitive powder. You may find the thread below interesting. Some graphs posted by kombayotch were very informative.

http://www.accurateshooter.com/forum/index.php/topic,3754350.0.html

 

[necchi]

Viperdoc, my experience with Hodgdon Extreme powders is that you can do load development in any weather you can reasonably stand, say down to 20F, and use the loads in the heat of summer just fine. If you find a good load with Varget, Benchmark, H4198, etc., at most it will need a .1 to .2 tweak in the hot weather but a good load in cold is still a good load in heat.

I think you have that backwards......a good load in hot temps will work in cold, but a good load in cold may well lock up your gun in hot weather!!!! I don't care what kind of powder you use. Most guys load to the edge, which could be friggen dangerous when shot in hot temps.

4xforfun; you are wise to urge caution. But I'm another one that's useing Hodgdons Extemes powders Because I live in MN, and if we only did load development when it's hot, we'd only be able to shoot 4-5 months a year.
Anyone doing load work in cold temps would be wise to drop a tenth or two come summer 80* temps just to check, but so far I haven't found a problem with 3 different guns and cals. Varget and H4895 have let me keep my sweet loads summer and winter.
I'm going out today to run an OCW comparison with my 308 and some 168SMK's w/Varget, I've had the ammo in the fridge for 4 hours now and the gun in the truck for 2, that way all will be consistant with the outside temp and prevent swings

Viperdoc, try the Extreme powders and have fun without feeling guilty. Besides you don't have to wait as long for the barrel to cool ;D

 

[bigedp51]

As long as you don't have two feet of snow on the ground go ahead and work up loads.

Just remember to bring an ice scraper to the range and a space heater.

It always helps to study and practice under the actual conditions you will be shooting at.

 

[CJ6]

necchi It's colder outside today than in your fridge I'd bet, 28deg in Austin Mn.

 

[FURMAN]

I have done a lot of load development in 25-30 degrees and then proven them in the 70-90 degrees I normally shoot in. I have not found much if any difference in most loads. Some loads may need tweaked but a majority of the development is over.

 

[necchi]

"It's colder outside today than in your fridge I'd bet, 28deg in Austin Mn."

Ya, but I didn't want nice warm ammo for the 1st 15 rounds, then cold stuff for the last,, ;D It was 33 here in St. Cloud, piece a cake

" If you enjoy ice fishing while seated out in the open on a five-gallon bucket, the Norse Gods must be with you."

"Well Yaa, you betcha",
Course I only have half an ear left on each side, my fingers been froze off to the second knuckle an the end of my nose is permenatly purple.
You guy's had heaters in the Fishin Shack? ???

Actually it was a good day, couple layers, sun was shinning, and the key is, there was little wind.

 

[Viperdoc]

It was 18 degrees here in Wisconsin yesterday, but at least no snow. You are right about needing to be tough to shoot in these conditions ( or dumb). I have really been enjoying working up loads and using the chrono data to fine tune, but did see nearly a 200 fps difference with my 6.5 CM loads using Reloder 17 from the summer, which raised the initial question. Went trap shooting instead. However, prepping brass and making ladders is not much fun without testing the results.

 

[CJ6]

200 fps difference for you, A 7 STW I have needs 5.3 grs more H-5010 to get BACK in tune @ 20 deg vs 80 deg. Extreme I know but it's a good example for tuning for Winter loads.

 

[Clark]

http://www.canadiangunnutz.com/forum/showthread.php?p=5023569#post5023569

After you look at velocity vs temp for those powders, scroll through and see how kombayotch [Kris] responds to my questions on how he controlled the test.

I went through a similar experience with his testing of Copper solvents. He doesn't just understand scientific method, he is responsive.

 

[4xforfun]

You guys are missing my point!.. If you keep your ammo warm and your gun warm (either through shooting it or the heater) you can find your summer tune and you CAN'T find a winter tune...I don't care how cold it gets......your gun and ammo are at summer temps.....they will shoot just like they do in the summer. But, like mentioned above...if you plan on shooting something in the winter, you will need to tune in the winter(without all of that comfy heat)...unless you have your bench and ammo set up in a freezer.

Cold gun/ ammo combos shoot different than warm gun/ammo combos. It is as simple as that. And I do agree that some powders are affected less by temps than others, but, they are still affected. You can find a summer tune in the winter if you keep things warm (including yourself).

Anyone who shoots 1K benchrest can tell you. If you leave your ammo in the direct sunlight, your groups will probably open up, and probably your bolt lift will get sticky (at the very least) also. I keep my ammo in a cooler out of the direct sunlight during a match

 

[CJ6]

Depending on time between shots your barrel is cooling much faster/Heating up less @30 deg than 85 deg It's just another unwanted variable IMHO.

 

[4xforfun]

Depending on time between shots your barrel is cooling much faster/Heating up less @30 deg than 85 deg It's just another unwanted variable IMHO.

I agree. And yes, there are more variables in winter than summer. I am just saying that you ARE NOT waisting your time shooting in the winter, provided you do it right.

And, trust me...I know winter. They say International Falls, MN is the coldest place in the contenental US.......The only reason they get to call themselves that is because it is the year long ave temps.....We are usualy 5 degrees colder than them in the winter...BUT also 5 - 10 degrees WARMER than them in the summer.