So, I traded away a P229 Legion in 9mm for a P226 Legion in .40 S&W. Looking at the overall measurements, the guns are nearly identical other than the barrel length. I figured I was in good shape. The grip design is completely different, however, and I ended up installing a short-reach trigger. That made things pretty much, almost, very close to, being just right. What I really want is a P220 Legion in 10mm. They are comparatively super expensive to the other Legions. So, I am not getting one any time soon. What does this have to do with caliber talk, you say? Well, I am using Underwood 165gr Gold Dot rounds in the P226, which have the following specs, according to the website: Technical Information Caliber: 40 S&W Bullet Weight: 165 Grains Bullet Style: Speer Bonded Jacketed Hollow Point Case Type: Ducta-Bright 7a Nickel Plated Brass Ballistics Information Muzzle Velocity: 1200 fps Muzzle Energy: 528 ft lbs Now, comparing that to the Corbon 165gr 10mm offering, this is the info on their box: So, the Underwood .40 cal averages 50fps less than the Corbon 10mm. Looking at speeds exceeding 1000fps, I am not sure how much difference 50fps really makes. In addition, looking at this graphic which all 10mm fanatics love: Both loads sit in the 2nd column of the Medium Load column (+/- 25fps) So, does this mean that my P226 using Underwood 165gr .40 cal is actually the rough equivalent of a P220 10mm using Corbon 165gr (or comparable commercial big-box "warm" 165gr 10mm rounds), except I get 12+1 rounds instead of the P220's 8+1? This is the kind of rambling post you get when the poster has had a rough day and is browsing the gun forums after taking a Clonazepam (not for seizures). Enough for now. Goodnight!