groove diameter 10mm auto

[grizzlypaul]

recently acquired a kimber target II in 10mm auto. slugged the bore and found .402 this seems odd to me and kimber has not been helpful. is this out of spec for the cartridge? the chamber checks out at .424 at case mouth to .426 at the head. I'm going to run into a tight situation if I go with a .403 bullet. Any thoughts will be appreciated, thanks

[Hammerhead]

SAAMI spec's call for a .4005" groove diameter, but I don't see a +/- tolerance figure.
.402" seems large considering the vast majority of projectiles for the 10mm are .400".
http://www.saami.org/PubResources/CC_Drawings/Pistol/10mm%20Automatic.pdf

[ReloaderFred]

I size all my cast bullets for my several 10mm handguns at .401", and they are all deadly accurate at that size, with no leading problems. My pistols come from Colt, S&W and Tanfoglio, and they all like the .401" diameter.

Hope this helps.

Fred

[barkerwc4362]

I use .403 in my recently acquired S&W 1006. With .401 I was getting more leading than I liked. With .403, leading problems went away. My son uses .401 in his H&K USP with no problem.

Bill