During a ammo test secession recently my last round of the test was the Underwood 220 grain, this bullet measured 0.4010" as pulled before the testing and had a full lube groove of what ever red lube was being used by his supplier.
Being the last round and only cast bullet shot, I had plenty of leading in the barrel of my S&W1006 and it was tough to remove...
Cartridge is from Ammo Manufacture: Underwood 220gr Hard Cast
Ballistics Information: 10mm Auto
Muzzle Velocity: 1200 fps
Muzzle Energy: 703 ft. lbs
Pictures: Before/After disassembly:
Brass Make/Headstamp: Star Line - Brass
Bullet Make/Weight/Construction/Info; Length 0.7360"/Dia. 0.401"/Meplat 0.280": Hard Cast 220gr. HC actual weight 219.0 grains top band 0.1800"/bottom band 0.2200"/lube groove 0.1500"/nose 0.2250" (doesn't add up exact nose profile?)
Primer: Brass color
Case: Diameter 0.4215" Crimp Diameter 0.4220" Length 0.9865"
Powder Description/Positive ID/Type/Charge Weight: IMR800X 8.4 grains
Tested 11/29/2012 Underwood 220 Gr. Hard Cast WFN 1209 fps : Diameter 0.4285" primer moderately flatten, case didn't eject. 12/01/2012 barrel inspected and cleaned plenty leading to remove, maybe not enough lube or the type of lube.