I'd look for a Sauer Model 60, their basic boxlock. Most are quite light yet still balance well, and never shoot loose. Mine weighs 6-1/4 with 28" barrels. It's choked the typical "old German" tight and tighter, but it sounds like you're handloading anyway, and it's easy to make spreader loads. Mine's my favorite shotgun, and have used it on everything from doves to turkeys.
