Loading rifle cartridges for cold weather

S

steve allen

New member
I have found out the hard way that when it comes to reloading rifle cartridges for cold weather hunting that not all components are created equal.

My worst experience was loading for a .22/250 using H414 with Winchester primers. These are both excellent components, but the combination of these 2 and temperatures colder than about +10 degrees was a disaster looking for a place to occur. Typically the groups would range between 2.5-3" in diameter at 100 yards. The worst part of it was that the rifle would shoot fine in warm weather, and it would shoot just enough good groups in cold weather to make me think it was me and not the components.

Finally, on the advice of a friend, I bought some Remington and Federal primers to try; everything else remained the same. It was like a new rifle. The groups went from the basic 3" down to 1/2" or better instantly with both the Remington and the Federal primers. After doing some reading I found that Winchester primers are apparently the coolest burning primers available, and the slower burning ball powders (e.g. Blc-2, H414, etc.) are the hardest to get uniformly consistent ignition and require a hot primer. Thus, I had unknowingly shot myself right square in the foot by combining a series of components destined to perform miserably on a regular basis in cold weather.

Have any of you guys had similar reloading surprises in either cold weather or hot weather country?
 
Steve, I experienced enough temp. related headaches using H-380 in the .22-250 that I gave it up for hunting ammo.

Actually had some scary high pressure occur in extreme cold with a load that was fine in warmer weather. Asked enough people about it that all told me that it couldn't happen that way that I started to think I was nuts or something. It was a few years later that a Hogden employee told me that yes indeed it was possible to see a pressure spike related to extreme cold temps using ball powders like H-380. I don't know anyone else that has had this happen, falls under "strange but true" I guess. I was using magnum primers too, by the way (Fed 215).

And of course there is always the sticky bolt that shows up after letting a round sit in a hot chamber waiting for a p-dog to pop his head back up from a load that never showed pressure signs before.

Anyway, there are SO many propellants available with better temp stability properties, that work very well, that I just don't mess around with powders like H-380 in applications subjected to wide temperature swings anymore. Powders from Hogden's Extreme line really do show superior temperature stability. But just about any extruded single base powder will show less temp. sensitivity than most ball powders.

That said, it is still pretty tough to beat some of the old ball powders for a combination of velocity and accuracy. Not to mention that they meter like water and I for one despise weighing powder charges. So I do still use these powder types in some applications. Including keeping separate loads for different seasons.

Another temp related ammo problem I experienced was 55 gr. Vmax shooting like they had eyes out of a particular 14 twist factory .22-250 barrel when it was warm, but not stabilizing them when it was cold. Apparently they were on the ragged edge of stabilization out of that combo and shot great in warm air but never went to sleep in colder more dense air and would keyhole and scatter all over the place.

The moral of all this is that it pays to test ammo in conditions similar to what you expect to encounter in the field. That load that printed all those nice groups and showed no pressure signs on that beautiful morning last spring may well cause ejector marks, sticky bolt lift and leaky primers on a hot day in July and then not group in a #3 wash tub come January. One thing I routinely do during load development is take and "cook" a few rounds on the dashboard of my vehicle with the heater running, get them good and hot to the touch, then see how they act - both on paper and across the chronograph. This is a step I never skip in working up loads for p-dogs or chucks - it's not unusual for both ammo and chamber to get pretty warm shooting colony varmints. I have also kept ammo in the freezer overnight and tested it the next morning - though not very often. Usually it's easier just to wait until winter to test for winter conditions.

Looks like I'm getting long winded as usual... Sorry 'bout that.

- DAA
 
DAA--Those are some really good observations. I think you have see more of this wierd stuff than most shooters I talk to. It certainly pays to experiment with loads in a variety of weather conditions that one expects to use them in. That was a very good post, too. They are never too long if they have good stuff in them like yours did.
 
I like to choose a load that has near 100% loading density, so as to more closely fill the case. Using Hodgdons Extreme powders like Varget or H4350, ect... with magnum rifle powders if using more than around 45 grains or so of powder. I also use George and Roys primer sealant around the primer and bullet case junction, very lightly, I should add. And buying a chronograph was one of the best investments I've ever made in the shooting sports. No more guesswork.

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"Doing the right thing isn't always easy, but it's always Right!"
 
It happened to me DAA, and it wasn't extreme cold, worked up a load in june for my STW in oct it was hot, hot hot. it was averageing 140 feet per second more than in june and extraction was sticky to say the least. had to back it down 2 gr. for winter use. I was using H-1000.
RR

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Born to hunt, Forced to work
 
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