Underwood 140gr Lehigh Controlled Fracturing Hollow Point Pull-Down

[The_Shadow]

Cartridge is from Ammo Manufacture: Underwood 140gr Lehigh Controlled Fracturing Hollow Point (100% solid copper)
Ballistics Information: 10mm Auto
Muzzle Velocity: 1550 fps
Muzzle Energy: 746 ft. lbs
Brass Make/Headstamp: Underwood - Brass
Bullet Make/Weight/Construction/Info; Length 0.6730"/Dia. 0.3910": 140gr CF
Actual weigh 139.8 grains  Crimp Diameter 0.4000" *
HP Depth:  0.4200" / HP Cavity: 0.1730 tapered / HP Mouth 0.2375" (Three segments cut to 0.4045" to the first band) 
C.O.A.L.: 1.2540"
Primer: Large Pistol Nickel color
Case: Diameter 0.4215" Crimp Diameter 0.4220" (Light Crimp)Length 0.9870"
Powder Description/Positive ID/Type/Charge Weight: LongShot  11.6 grains

*Base was smaller @ 0.3910" crimp area 0.4000"

[Intercooler]

I had a hunch these weren't Power Pistol. They didn't have that sonic boom.

[The_Shadow]

Read about the base section of these bullets being smaller than 0.4000"    That would be less frictional surfaces, it would also lead me to believe they would be less accurate at long distance.