Training guns, "real" weapons...
I've seen a few well made training aids; ASP, Blue-Ring guns, Blackhawk etc.
The ASP line that mimics the exact size/wt of a loaded pistol has a lot of merit but is only available in a Glock 17 a full size 1911A1 .45acp a M9 9mm & a SIG P226R.
The fake or rubber guns can help with high speed or "dynamic" drills that could occur in a real, violent use of force event.
I'm not a student of the bang & break school of tactical training. Hard use or bad elements(rain, snow, dust, sand, mud, etc) might occur but fake guns are safer & better for simple drills like weapon retention, weak hand draws, speed draws/quick draws, re-holstering, weapon transition(rifle to pistol, shotgun to pistol, etc).