I bought a 12 gauge Model 12. I hardly use my 16 gauge double anymore maybe once a year.
I'm starting to run low on 12 gauge and getting a little desperate.
Here is the chamber pressures I have;
Kent's TM
2 3/4 length shells, 1 3/8 oz. 11,400 psi.
2 /34 length shells 1 1/4 oz. 9,900 psi
Kent's bismuth,
2 3/4 length shells 1 1/16 oz. 9,800 psi
2 3/4 length shells 1 1/4 oz. 10,000 psi
If you're using a Model 12, why concern yourself with low pressure loads? Kent TM would be fine for your gun.
#1 shot only but as cheap as you'll get it anymore
Kent TM