I'm need a 357 load using unique for 158gr jacketed bullets. I want to get about 1050~1100 FPS out of 6in guns. Best I can tell from the manuals I have I'm thinking that 7.5gr will do it.

Any of you guys have any first hands experence you can share?

I tried some Unique under a cast 140. It was mild and accurate but the charge I wanted to use wouldn't meter reliably out of my Lee Auto Disk so I wound up going with Accurate No. 5. It meters wonderfully and has a burn rate close to Unique.

My only complaint is that it lacks bulk for weight so my 8.5 gr charge isn't visible looking down the case while it's in the press (I use a Lee turret). So I've taken to looking at the measure to watch powder drop to make sure I don't do a squib. A double charge of this also fits the case but will be visible when looking at it in the shell holder so that's my check on the high end.

Being ever the tinkerer I also want to try No. 7 and Universal for building these light-magnum loads.

Here's a 7 yard group of the 140s over 8.5gr No. 5 from my 66: Scott Johnson's Photos | Facebook

They chrono around 1,010 on average.

alliant states 7.7 for 1040. I think that is a little conservative,and you'll find yours going faster then that.

I use 7.5 under a bulk 158 jacketed all the time. Nice, pleasant shooting, accurate plinking load.

You might try here...
357 Magnum Load Data - Handloads.Com

I don't have my chrono data in front of me, but I found that 7.3 gr is about right for my guns. The pressure increases much more than the velocity when I load any higher. Definitely a solid, mid-range practice load.

Sorry! The info I gave was for 158 gr hard-cast lead.