Ryan already has a Kimber TLII, great handgun I must add since I have one also. The HK45 is little more than 1/8 thicker than the Kimber 1911. If he is comfortable carrying the 1911 the HK45 would not be much different.
Size specs on Kimber
http://www.kimberamerica.com/pistols/tactical/tactical_custom_II/
Size specs on HK45
http://www.hk-usa.com/hk45_specs.html
Size specs on Kimber
http://www.kimberamerica.com/pistols/tactical/tactical_custom_II/
Size specs on HK45
http://www.hk-usa.com/hk45_specs.html