The Howa 1500 is the same action as the Weatherby Vanguard (Howa makes the actions for Weatherby in Japan, then Weatherby finishes them and mount them in their stocks in the US). The Vanguard S2 has a three position safety and true two-stage trigger, as does the latest Howa 1500. Yes, the Howa in short action can take a detachable five or 10 round magazine. The Weatherby S2 in long action also has an available detachable magazine. If you are looking at the Howa, you may want to see the Vanguard S2. I bought the S2 and the fit & finish is great, and the trigger breaks like glass. Both rifles are pretty heavy compared to their competitors.
Here are the Vanguard and Howa websites:
http://www.weatherby.com/product/rifles/vanguard_2
http://www.legacysports.com/products/howa_hogue.html