Cartridge is from Ammo Manufacture: Underwood 180gr FMJ (plated)( supplied by Intercooler 12/2015)
Ballistics Information: 10mm Auto
Muzzle Velocity: 1350 fps
Muzzle Energy: 728 ft. lbs
Brass Make/Headstamp: Underwood - Brass
Bullet Make/Weight/Construction/Info; Length 0.6020"/Dia. 0.4000": 180gr. FMJ
Actual weigh 179.8 grains Crimp Diameter 0.3970"
Meplat 0.2500" concaved base
C.O.A.L.: 1.2505"
Primer: Large PistolNickel color
Case: Diameter 0.4215" Crimp Diameter 0.4215" Length 0.9880"
Powder Description/Positive ID/Type/Charge Weight: Lovex D037.01 13.0 grains*
*(same load weights as AA#7) same as Shooter's World - Major Pistol powder
(https://s20.postimg.cc/9srosmgjh/IMG_0257_zpsbxoe1zic.jpg)
(https://s20.postimg.cc/p1hm6ehxp/IMG_0258_zpsmupucsaf.jpg)
(https://s20.postimg.cc/qgj6v4qql/IMG_0259_zpswwungcx4.jpg)
(https://s20.postimg.cc/cmuu635uz/IMG_0260_zpshcqwgf6k.jpg)
Hmm.. No 800-X this time..
So this is a newer one during the powder shortage.
Underwood shows this for these 180gr bullets on their site;
QuoteTechnical Information
Caliber: 10mm Auto
Bullet Weight: 180 Grains
Bullet Style: Speer Total Metal Jacket
Case Type: Brass
Ballistics Information:
Muzzle Velocity: 1350 fps
Muzzle Energy: 728 ft. lbs.
Glock 29 3.8" Barrel
Muzzle Velocity: 1249 fps
Glock 20 4.6" Barrel
Muzzle Velocity: 1300 fps
Colt Delta Elite 5" Bar-Sto Barrel
Muzzle Velocity: 1350 fps
Para Elite LS Hunter 6" Barrel
Muzzle Velocity: 1390 fps
This is the one I was shooting and produced strange hard residue, and some rounds produced a lot more than others and seemed underpowered.
It's hard to say what's going on with the ones you have, but this powder usually burns clean. Was it a very cold day where you shoot? Another thing that comes to mind is loose bullet fit may not have allowed a full power burn and pressure development.
The powder Underwood is using in these rounds is a LOVEX D037.01 or Major Pistol powder. Shooters World seems to be the supplier under the name of - Major Pistol powder.
I had samples of this powder and tested it to be sure of the yield. This powder is said to use the same load data as AA#7.