I’m suspicious of the SNS lead bullet. I doubt you’ll get satisfactory results at velocities much over what they’re intended for which is .32 S&WL velocities (850fps).
I’ve used Brian Pierces .32H&R data in my .32Mag and .327. They are warm loads intended for strong revolvers, but are certainly safe.
That said, I used LilGun with either jacketed bullets, or, gaschecked bullets with conventional lube and .314” sizing with a harder alloy. My results were outstanding. However, I loaded a few with a Lee 90gr TLSWC with either Tumble lube or Powder Coat and was NOT happy with the results.
Best results were with the Hornady 100gr XTP. Even better results were had with H110.
I suggest you load a few with the LilGun at 10.0gr and see how they shoot. That is a factory equivalent load for about 1,170fps (1,000fps from the 1-7/8”bbl). If accuracy and leading is acceptable, then I’d try a few at 11.0gr. Any higher will be counterproductive as velocity’s will drop, instead of increasing.
Lil’Gun does the same thing with the .357mag. With a 158gr JSP, 17.8gr gives peak velocity. Increasing powder charges reduces velocity.
For future efforts, I suggest LongShot. Velocities are similar, but change weights are about half.