Cartridge is from Ammo Manufacture: Norma 165 grain JHP **(turned out to be 170Gr Bullet)
Ballistics Information: 10mm Auto
Muzzle Velocity: 1400 fps
Muzzle Energy: 717 ft. lbs
Brass Make/Headstamp: Norma – Brass (weight 77.8 gr.)
Bullet Make/Weight/Construction/Info; Length 0.6300"/Dia. 0.4000": 170gr Norma JHP
Actual weigh 170.2 grains (concaved base) Crimp Diameter 0.3995"
HP depth HP 0.1600" / HP dia. 0.1750" (tapered) / mouth 0.2725"
C.O.A.L.: 1.2525"
Primer: Nickel color (NP)
Case: Diameter 0.4235" Crimp Diameter 0.4220" (medium) Length 0.9870"
Powder Description/Positive ID/Type/Charge Weight: ? NORMA R-123 ? 10.4 grains **(The other 170 had 12.8 grains)
http://10mm-firearms.com/factory-10mm-ammo-pull-downs/norma-170-grain-jhp-(original)-pull-down/ (http://10mm-firearms.com/factory-10mm-ammo-pull-downs/norma-170-grain-jhp-(original)-pull-down/) That would explain the difference in the test velocity seen by IC.
Intercooler's Tested Velocity:
EAA Limited Pro 4.75" 1309, 1308, 1293. Average = 1303.33 FPS/ 622 LBS
EAA Hunter 6" 1372, 1342, 1303. Average = 1339 FPS/ 657 LBS
(short rod shaped, some golden and some darker, some rod are perforated hole in the middle)
(Vihtavuori Powders exhibit many of these characteristics)
(https://s20.postimg.cc/9wxv4ewa5/IMG_0278_zpsfb7954e4.jpg)
(https://s20.postimg.cc/3w067cp3h/IMG_0279_zpsc093de6c.jpg)
(https://s20.postimg.cc/pv6kukdnh/IMG_0280_zps9115b4e2.jpg)
(https://s20.postimg.cc/kwj2g1hkd/IMG_0281_zpsd0384879.jpg)
That explains a bunch of stuff. Wonder why they labeled the boxes with all the wrong stuff? :o
Is this a different powder for the 165's? I got a higher velocity with the less powder 165gr :o
That's a mystery to me :-\ and most people don't pull rounds down or shoot over a chrony much less recover the bullets, so they wouldn't know the difference one way or the other.
There was a slight difference in bullet measurements, but the weight was 170.2 grains... ::)
I have noticed with the Norma rounds they are very up and down for some reason.
I'd bet that this powder didn't meter very well thus the wild fluctuations in powder charges and velocities... ???