Here are some pictures of lube deposits left in the bore of my M73 357 Mag Sporter. I am working up loads using different alloys, so the weights and hardness vary. My first attempts leaded badly where I tumble lubed by itself with BHN 12 alloy. I decided to overlube the bullets and change powders, so I tumbled in Xlox, then sized to .358, then lubed in my Lyman 45 using a .3595 die and Carnauba Blue from White Label and then tumble lubed again in Xlox. Of course, I let the Xlox dry after any coat was applied. My powder of choice is HS-6 with this experiment at 7 grains, bullet weight was 174 grains BHN 11.8. That mix produced a fairly close ten shot group at 50 yards so it's a good start.
Now after the range session I needed to see what leading if any was present in the bore. I ran the scope down her and found zero lead accumulation. Some unburnt powder, just a couple of grains really left behind as I used Small pistol primers not magnums. The coolest part for me was to see blue lube deposited throughout the bore in thin streams. I had a lube star also at the muzzle crown. I was very happy with that result. This lube combo might smell like crayons but is clean and works very well over a 24-inch barrel. Fine tuning the powder charge will tighten things up. The numbers were also pretty good with average fps at 1251, ES at 56 and SD at 15. No signs of pressure. I think I can achieve 1350 fps.
The second picture is the throat area where the blue lube is as well. The above lube is awesome for me. Cleaning my rifle was a snap.
After a careful look at previous targets I came to the conclusion that I will size to .3595. That sizing in previous loads was actually superior to .358 for my gun. The group sizes were very small at that dimension. I firmly believe that lube in the proper amount and type had the biggest impact on not leading the barrel. I already had the groups but was not providing enough lube and I went down a size thinking it would help. Better fit was at .3595. Groups shrunk. BHN of 12-15 is the hardness. Next batch should prove out and get me a solid consistent load at 174 grains. I'll keep my powder charges consistent.