Tim Cartmell,

You might check to see if B&P (Baschieri & Pellagri) has a distributor in Canada.

They make several hunting & target loads in both 2 1/2" & 2 3/4"
that would be of appropriate pressure for an 1 1/4 oz /2 3/4" proved gun.

Their shells are of excellent quality & they list the pressure of their loads under the CIP standard.