320090T, the information contained in the 2003 manual is still the best. Newer manuals use a crimp depth of 0.80" instead of the standard .055". I asked their ballistician why and was told they wanted to make absolutely sure they were not understating their pressures.
Here are some loads from that manual:
GM hull, W209 primer, 12S3 wad, 23gr Solo 1250, 1 1/8oz shot, 1200fps, 7100psi. This is the lightest load they list.
same components using 23.5gr, 1255fps, 8000psi.
same components using 25.5gr, 1310fps, 9600psi.
BTW, the previous ballistician told me he would not use 1250 for anything under 1 1/4oz @ 1250fps, because that's when it really started to shine.
Before I stopped hunting with a 12 ga I used 1250 to load 1 1/4oz @ 1220fps. It was a very nice load, but dirty with lots of unburned powder in the bore. I never bumped the load up because I didn't want the additional recoil.