Ians sig line reads "It's not
how you do it, it's
the way you do it."
This has never been more true than when mixing alloys. Keiths preferred 1:16 alloy runs around 11 bhn according to the alloy calculator and is a simple 2 part alloy as you know. Alloys are developed to meet specific needs, and for a 357 mag lever gun or revolver you will want to look closely at terminal performance where hunting deer is involved. 357 mag is a bit light for deer, but you can stack the odds in your favor a bit with alloy selection. I've seen you get a lot of advice to use a harder bullet for deer, here's why.
A cast bullet kills game as a feature of its design, coupled with it's penetration in game. Softer bullets deform quicker and easier because the strength just isn't there for bullet integrity. A harder bullet will penetrate deeper with far less deformation than a softer one. I'd prefer a full diameter hole completely through a deer to the chance of a bullet that can't penetrate because it has expended too much energy in deformation, think of a parachute opening. The effect is similar enough in this instance, the bullet enlarges and generates a larger surface area which slows its progress. This is okay if you're starting out with a heavy bullet at much higher speed but decreases the all essential penetration. On the other side, too hard of an alloy could fragment.
You mention not wanting to "dick" around with a little of this, and a little of that, but that is how it works. At this point I'd suggest contacting Rotometals
https://www.rotometals.com/bullet-casting-alloys/ and buying #2 alloy so you don't have to do this. #2 alloy also heat-treats well if you want to experiment with that as well. I see Rotometals has #2 alloy on sale right now too.
https://www.rotometals.com/lyman-2-bullet-metal-5-pound-ingot-90-lead-5-tin-5-antimony/
Buy enough for a couple of pots full if you can swing it, and save the soft stuff for practice and plinking.