10mm vs. 45 Super Episode 3 200gr Hardcast

[AlaskanBallistics]

Im surprised the Underwood chronograph velocities  was so low... especially considering the 6.5" kkm barrel... any ideas why?

[Spudmeister]

Good video BTW.... but you need a new chrono.

The 6" KKM barrel on my G40 has no trouble reaching 1,275 to 1,290 (depending on the exact bullet) with quality hardcast bullets in my reloads.  Even my "light" hunting load does a bit over 1,200 fps.  Underwood likes to get every last fps possible out of their loads.  I can only presume it was as fast/hot as they could load them and get them to work universally in many makes of gun. Buffalo Bores numbers were similar. Guys drive the coated bullets pretty fast so I don't think that's it.

So my guess (it is a guess) is the Underwood ammo you test fired is as hot as they and BB know how to make it and still make it run in all 10mm handguns. If they made loads specific to well sprung 6" Dan Wesson's and G40's with 6-7" KKM barrels, I think you'd see far more impressive ballistics.

[4949shooter]

Better sectional density with the 10mm.

Good video and thanks for posting.