Printable View
This probably only applies to the northern shooters, but does anyone else have winter or cold weather loads when they reload, or do you just compensate, I make small batches of whatever I am shooting, and it seems to work, some of the "cold" loads I shoot, would spell a blown primmer or stuck case in the summer, and I don't even a flat primmer in the winter, inquiring minds would like to know.
Tanks Dean
I never even thought of it,but I use the same loads spring,summer,and fall as well as winter time..
And I have never seen and difference...I once left some ammo out in the sun during a match and
that was a disaster..My second relay was really bad.The loads all over.I say it was from the hot
ammo rising pressures....
Depending on how cold it is, I have see as much as 300 to 400 fps or 10% drop when it is zero or less out, compared to July shooting,
there's nothing like a hot barrel to warm your hands.
Tanks Dean
??????????????????????????
I tend to shoot my rifles as I use them and under the conditions I use them or as close a possible. In other words I don't often shoot my big game rifles in July when the temps are in the 80s-90s or my vermin/paper punchers in November when the temps are in the 30s-40s.
Bill
vihtavuori powder has addressed this issue pretty well for me, they have one of the smallest changes between very cold and very hot of any powder I have used. I shoot a lot of milsurp powders in rifles and have to be careful of loads from one season to the other. Bllitzfike
Hodgdon Extreme powders are made to not vary much with ambient temperature. I try to use them as much as I can.I shoot year round and it gets 90+ sometimes hunting g-hogs.
my primary loads for my 25-06 get backed down 0.5 grains of powder during the summer. right now, Im back at 55.0 of IMR4350 with no pressure signs, the same load in july flattens primers and start to flow around the firing pin. None of my 30-06 loads are loaded hot enough to matter, they're just for shooting whitetails.
No matter what you do, there is always going to be at least a little change in the way the load performs when you go to the extremes of temperature. However, I try to work up loads that tend to be more tolerant of temp changes. Part of that is the powder (I like Hodgdon's Extreme series when applicable) and some of it is the primer chosen, but a lot of it is the exact load you choose. I like to develop loads in middle-range temps (around 50°-70° F in my area) if possible, but I also tend to use either a ladder or OCW method to find a powder charge that is somewhat flexible. I look for a place in the powder charge where the load seems more tolerant of changes in the powder charge weight without any significant effects. As an example, for an average-sized case such as a 308 Win, I will settle on a powder charge that allows at least a 0.3gr change up or down from nominal without any major effects to velocity or accuracy. This doesn't always allow the most accurate load or peak velocity for a given condition, but it does give good results across the board and keeps me from having to chase the powder charge up or down every time the temp changes. Since I changed to this style of loading several years ago, the occurences of "What happened, it was shooting fine last week!?" have been greatly reduced. Now it's usually just me when a rifle starts slinging bullets all over the target for no apparent reason.
That is an excellent way to develop your loads unless you are chasing the single hole group like I do from the bench. I do use that method for my standard hunting loads.