I know that there are a number of experts who frequent this board who are knowledgeable about double rifle regulation - I'd really appreciate some input.

I'm hoping to turn my 9.3x74R/12ga/12g (3") Merkel into a poor man's paradox. Currently the elevation of the shotgun barrels with either Forster or Brenneke slugs is the same as the rifle barrel with 286g loads.

The problem is that the barrels cross with both slug types (Winchester Forster's worse than Brennekes) at about 15 yards ie the left barrel shoots about 5-6" right at 50 yards and the right barrels shoots a similar amount left.

It would seem to me that I need a heavier projectile, going slower to move the barrels apart - I thought something like the 600-700g projectiles used in the Paradox or Explorer cartridges in the late 19th century.

Where can I get moulds for heavy 12 bore projectiles;
What load should I start with;
What about round balls;
What cases etc.

I will be using RCBS 12ga dies in a Rock Chucker.

The gun has Briley Series 2 choke tubes and I'm told that rifled tubes will improve accuracy (and would make it more like a "real" Paradox - any comments.

Another option is to have Briley make eccentric unrifled choke tubes which they report can move a pattern 5" at 40 metres but they have never tried it with slugs and i couldn't have rifled tubes - any comments.