Surprised. Tactical, same as the .45 ACP gun but chambered for the 10mm round. The extended magazine is 22+1. I didnt get the barrel dimensions and it does not appear to be full size auto like their .45 Tactical. Maybe it just seems smaller. Post away 10mm guys.

They're quite popular I think. I see them flying through the LGS I frequent. It's the third mainstream polymer-framed 10mm on the market (that I know of) and probably the one I would go with just based on how they all handled.

The 510 is the same size as the 545 according to the specs on FN's website.