Cartridge is from Ammo Manufacture: Double Tap 180gr Speer Gold Dot JHP (provided by Intercooler 5/6/2015)
Ballistics Information: 10mm Auto
Muzzle Velocity: 1200 fps
Muzzle Energy: 527 ft. lbs
Brass Make/Headstamp: Double Tap DT - Nickel
Bullet Make/Weight/Construction/Info; Length 0.63650"/Dia. 0.4000": 180gr. Speer GDHP HP depth 0.2400" / inside Dia. 0.2100" tapered / mouth Dia. 0.3000"
Actual weight 180.6 grains (concave base) Crimp squeezed bullet to 0.3910"
C.O.A.L.: 1.2420"
Primer: Large Pistol Nickel color
Case: Diameter 0.4205" Crimp Diameter 0.4155" (Tight) Length 0.9880"
Powder Description/Positive ID/Type/Charge Weight: IMR800X 8.8 grains
(https://s20.postimg.cc/8lydkszlp/IMG_0066_zpsoali09id.jpg)
(https://s20.postimg.cc/wpp593xi5/IMG_0067_zps4bpdpqsc.jpg)
(https://s20.postimg.cc/ea4obpr3h/IMG_0068_zpszgomfmrv.jpg)
(https://s20.postimg.cc/jyaz2nsvx/IMG_0069_zpseiojbiic.jpg)
The old Underwood achieved 1300 FPS with 9.4gr's. It makes sense these come up short by a decent amount.
Quote from: Intercooler on May 07 2015 03:01:27 AM MDT
The old Underwood achieved 1300 FPS with 9.4gr's. It makes sense these come up short by a decent amount.
Doesn't stop his website from saying 1300fps.
I don't know what's going on at DT. One batch tested better than flap and most of the last ones were stinkers.
0.4115" crimp...
Why do manufacturers put such a tight crimp? I thought you started losing neck tension after a certain point...
Yes, the crimp on that one was little extreme and you can clearly see the amount of indentation imparted on that Gold Dot.
Have seen seen some cases buckled due to the extreme crimps, that can cause the bullet to have less case to bullet tension.
The case itself was measured smaller than normal too, Star Line usually measure 0.4215" just above the extraction cut, this one was 0.4205".