What Drew Said;
You can look at any reliable loading manual & find loads with 1oz of shot @ 1200 fps using fast powders giving 10K+ pressures.
You can also find some 1oz loads at 1300 fps with pressures under 9K.
In this case if you think the 9k load is going to be easier on you or the gun you got a lot to learn.
So many seem to think that MAX PSI is the answer to everything, IT AIN'T.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra