Good news is I found a ton of stuff I was missing..everything from metal stock to tooling.
Bad news is my stainless scrap was limited to items not too useful to cannon making. Mostly thick rectangular barstock and sheet. here's what I have that may be of use:
1.5" x 0.40" rectangular in random lengths around 10-12"
0.730" dia x 8.5"
similar to above but last 4" is threaded and ~0.790 OD
2"OD x 3" L
1.9" OD x 2"L coarse threaded rod of some sort.
a few pieces of 0.745" OD a coupe inches long
3" OD x ~2" I have no idea what the alloy is but it hasn't rusted in 12 years being stored around corrosive chemicals and wet conditions
all my other rounds were 1018, 1045 or 4140