The powders are not 100% unaffected by temp.
does cold affect ammo performances
- Thread starter Still_free
- Start date
The powders are not 100% unaffected by temp.
X2. Hodgins may perform better, but temperature will still have an effect.
back again. Dang!! time goes by FAST. It was closer to 20 years ago!!
Okay, here's the data. We used a .308 Win.
Powder Chrg Primer Temp Velocity remarks
H-4895 45gn CCI 200 -30C 2718 Gradual increase in velocity
H-4895 45gn CCI 200 -10C 2738 as temperature goes up.
H-4895 45gn CCI 200 20C 2824
H-4895 45gn CCI 200 50C 2874 Temp-vel change 156 fps
IMR-4064 44gn CCI 200 -30C 2670 Low velocity variation between IMR-4064 44gn CCI 200 -10C 2643 low and high temperatures.
IMR-4064 44gn CCI 200 20C 2691
IMR-4064 44gn CCI 200 50F 2727 Temp-Vel change 57fps.
H-335 46gn CCI 200 -30C 2643 Only 7fps vel spread btwn H-335 46gn CCI 200 -10C 2676 standard and magnum primers.
H-335 46gn CCI 250 -10C 2683 Sharp Vel increase at high
H-335 46gn CCI 200 20C 2758 temperatures
H-335 46gn CCI 200 50F 2826 Temp-Vel change, 183fps
IMR-4064 was the most stable, giving variations not much different from the normal variations in commercial rounds fired in a 10 shot string. However, I still use H-335 and I don't hunt anywhere that it gets to 50 during hunting season. My rounds are usually worked up under 15C and in NS it is usually around 0 or -10C in November when I am hunting. Loss of about 50fps is not significant. If the temp really took a drop (like it does in AB), then I would re-chrony and re-sight in although even losing 100 fps would not change my point of impact. I use an MPBR allowing a 5" circle. Losing 100 fps would still be inside the 8" circle at whatever range I am shooting at. Still, I like to be accurate.
Okay, here's the data. We used a .308 Win.
Powder Chrg Primer Temp Velocity remarks
H-4895 45gn CCI 200 -30C 2718 Gradual increase in velocity
H-4895 45gn CCI 200 -10C 2738 as temperature goes up.
H-4895 45gn CCI 200 20C 2824
H-4895 45gn CCI 200 50C 2874 Temp-vel change 156 fps
IMR-4064 44gn CCI 200 -30C 2670 Low velocity variation between IMR-4064 44gn CCI 200 -10C 2643 low and high temperatures.
IMR-4064 44gn CCI 200 20C 2691
IMR-4064 44gn CCI 200 50F 2727 Temp-Vel change 57fps.
H-335 46gn CCI 200 -30C 2643 Only 7fps vel spread btwn H-335 46gn CCI 200 -10C 2676 standard and magnum primers.
H-335 46gn CCI 250 -10C 2683 Sharp Vel increase at high
H-335 46gn CCI 200 20C 2758 temperatures
H-335 46gn CCI 200 50F 2826 Temp-Vel change, 183fps
IMR-4064 was the most stable, giving variations not much different from the normal variations in commercial rounds fired in a 10 shot string. However, I still use H-335 and I don't hunt anywhere that it gets to 50 during hunting season. My rounds are usually worked up under 15C and in NS it is usually around 0 or -10C in November when I am hunting. Loss of about 50fps is not significant. If the temp really took a drop (like it does in AB), then I would re-chrony and re-sight in although even losing 100 fps would not change my point of impact. I use an MPBR allowing a 5" circle. Losing 100 fps would still be inside the 8" circle at whatever range I am shooting at. Still, I like to be accurate.
Hogdon/IMR 8208 XBR
Went from -40 to +165 with a net change in FPS that was 6 FPS according to their label if I remember correctly.
Should be an interesting powder.
