[SF_SN888KE]

Since you mentioned the 357 mag/38 spc, or the 44 mag / 44 spc; ever consider the old Marlin/Winchester rifles chambered for 44 mag or 357 mag as an addition? If you can't shoot the Sig 5.56, try an old lever action rifle partner.
If you can't make up your mind, I remember the old Thompson Contender's with interchangable barrels. Get it in .22 LR (cheap to shoot), 5.56 and 45 LC too. Single shot keeps the ammo price down!
I like the Colt Python and S&W Model 29 (Dirty Harry gun). "Do you feel lucky, punk?"