I've got a Bushmaster 5 round magazine, but it's as long as a 20 rounder. Does any one make a "short" 5 round magazine? Something that will just clear the magazine well...

BSJ, I use the CDNN 5/9 rd combo mags on my calling rifle. They stick out 7/8 inch below the mag well. They are a snap to disamble for cleaning.
I put the orange followers in mine and they work great for me.

I purchased a pair of 5 rounder mags(used), at a local gunshop. It Has the DPMS base plate, aluminum case, with green follower, probably early production. Sticks out just a little from the mag well.
Found out later that it actually holds 10 rds. It could be blocked to 5 rds. for hunting. Seems pretty rare.
Been to gunshows that have cheap 5 rounders made by various venders, even packaged by DPMS, but not made by them. Beware of these mags, they don't hold the bolt open on the last round, and need to be modified to hold 5 rds so the follower doesn't bottom out.It has an extended plastic bottom with "223 cal" imprinted on the bottom, with no manufacturer name or address.
There are other 5 rd. mags made by MWG (plastic), also a ribbed plastic mag made by DPMS, but the aluminum case w/ green follower 10 rounder by DPMS seems to be best quality and construction....if you can find one.