What gun? Chamber length? What do you consider low pressure? Weight of payload? The powder manufacturers have numerous lower pressure (sub 9000 psi) loads listed on their websites for 1 oz and under loadings. If you're wanting to load for shorter (2 5/8", 2 9/16" or 2 1/2") chambers, just about any 2 3/4" load will roll crimp into a shorter hull.
its a 1918 Ithaca Victory grade SBT.32"
it most likely has 2 9/16th" chambers but they can and I will take it out to 2 3/4".
the flues frame its built around are known to crack if modern ammo is used , but this usually happens on the doubles
i'm still trying to find the pressure thresholds that I can't exceed,
but I'm probably looking at something in the 1oz to 1 1/8oz payload of #9 for trap.