Did you come right? I'm new here, so I'm trying to work through some of the older stuff so I don't ask too many dumb questions that have been answered before.
I'm more of a revolver shot, but from other h/gun hunters I know most of their single shot shooting is done off rests (backpack, trees, anthills), shooting sticks, or some or other sort of supine, or prone, position.
Arms a little bent is always the most comfortable when shooting big recoiling handguns - like pushing in a push-up position off a wall slightly to just short of locking out. Bent too much seems to bring any large recoiler back at your face.
The balance on some of those sigle shots can be cr@ppy for off hand shooting.
That said, I think the "hunter Silhouette" class permits some Contenders with straight wall cases and is shot off-hand.
I suggest you visit your local / nearest silhouette club and ask around.THey will know way more than I ever will...
Check out http://www.lasc.us/
good luck with it.