Home Forums Hunting & Shooting Hunting Rifles Temperature vs Velocity - Gun Powder

Day 2 , -19C (-2F) . Rifles/ammo had been outside for hours. So cold they burned the hands packing them to the truck. Another 10 minute cold ride with a warm bum to the range, where they were set outside in the shade.


Ruger m77 Scout 223, 55gr Hornady SP, 21.8grs IMR 4198. In +20c (68F) to +7c (45F) the load does 2865/2817. Five shots @ -19c (-2F) = 2871 fps
Tikka CTR 6.5 Creedmoor, 130gr Sierra TGK, 42.0grs RL17. +5c (41F) 2749 fps, the day before -16c (3F) spiked up to 2817. Five shots @ 19c (-2F) = 2871 fps
Tikka CTR 6.5 Creedmoor, 147gr Hornady ELD, 45.1grs RL26. -2c (28F) 2524, day before -16c (3F) 2546. Five shots @ -19c (-2F) = 2533
Tikka 6.5 PRC, 140gr Nosler Accubond, 55.6grs RL26. +13c (55F) /-5c (23F) did 3049/3038. Day before -16c (3F) 3047. Five shots @ -19c (-2F)= 3075 fps
Tikka 6.5 PRC, 143gr Hornady ELDx, 53.4grs RL26 +10c (50F) 2942, +6c (43F) 2929. Day before -16c (3F) 2920. Five shots @ -19c (-2F) = 2925
Defiance 280 Ackley, 160gr Nosler AB, 60.0grs RL26. In +16c (61F) 2952, +6c (43F) 2951, -1c (30F) 2961, the day before -16c (3F) 3057. @ -19c (-2F) = 3001 fps
Defiance 280 Ackley, 165gr Sierra TGK, 61.7grs MagPro. -2c (28F) 2800, Day before -16c (3F) 2825, Five shots @ -19c (-2F) = 2800 fps
Defiance 280 Ackley, 195gr Berger EOL, 56.7grs RL26. +10c (50F) 2674, +7c (45F) 2655, day before -16c (3F) 2692. Five shots @ -19c (-2F) = 2677 fps
Ruger m77 Scout 308, 208gr Hornady ELD, 38.4grs Varget. +25c (77F) 2225, +12c (54F) 2193, -1c (30F) 2195. Five shots @ -19c (-2F) = 2215 fps
Ruger No1 300 Win Mag, 175gr Barnes LRX, 75.4grs RL26. +22c (72F) 3125, +18c (64F) 3116, -4c (25F) 3116. Five shots @ -19c (-2F) = 3067 fps
Defiance 338-06 230gr Hornady ELDx, 55.2grs Ramshot BigGame +10c (50F) 2534, -4c (25F) 2543. Five shots @ 19c (-2F) = 2489 fps
Defiance 338-06 250gr Woodleigh PP, 55.3grs Ramshot BigGame +17c (63F) 2482, +5c (41F) 2406, -1c (30F) 2402. Five shots @ -19c (-2F) = 2389 fps
Ruger m77 Guide 375 Ruger, 270gr Barnes LRX, 78.2grs Ramshot BigGame +10c (50F) 2636, +6c (43F) 2623. Five shots @ -19c (-2F) = 2578 fps
Ruger m77 Guide 375 Ruger, 300gr Nosler Partition, 78.6grs Win760 +23c (73F) 2580, -5c (23F)2512. Five shots @ -19c (-2F) = 2550 fps



On 10 of 14 (71% of tested loads) I was seeing equal or greater velocity in cold temps, compared to warmer conditions

I decided to try the same test the next day, but would just leave the ammo outside in the cold. Rifles would be room temperature. Should be able to see if gun/steel temperature is causing the increase in speed