9mm ultra light loads using reduced recoil spring. Recipes...?

[tz75]

This is my idea. I want two 9mm's setups.. One for higher pressure defensive loads.
Another one for plinking and for showing gun-shy family members how to shoot.
Anyone here use extra light 9mm loads?
If I use a 7lb or 8lb (or lower??) recoil spring, and 115gr or lighter bullets, and slow speeds, what kind of loads/velocities do I need to have safe and reliable ultra light loads.
I'm familiar with Bullseye or unique powder.
Should I use lead or fmj bullets?

[rinco76]

The lightest load I've ever made:

Case:            S&B
Primer:           S&B small pistol
Powder:          2.6 grain Vectan BA 10
Bullet:            Frontier 124 grain
C.O.L.:           27 mm

This was a very nice load for a maximum (accuracy) distance of 10 meters. It sounded and felt like a fat .22

[rinco76]

I used the copper jacketed ones. Vectan BA10 is one of the fastest burning powders available on the market.

Powder Burn Rate Comparison:

http://www.reloadersnest.com/burnrates.asp