Question: How to effectively increase pattern density by using 2 different shells.

I have a Damascus hammer gun choked .004 and .004. Probably had some choke in one barrel reamed out at one time. However both barrels still have .733 bores. Both barrels remain in proof for 2 1/2 inch shells.

I'd like to tighten the pattern in one barrel by using a different shell in the second chamber. I've been using a variety of manufactured low pressure shells.

Does a larger shot size accomplish this to some degree, or is there another factor?

Thanks in advance.

The only constant in life is change.