If you would like to give it a try there are two products that have worked well for me in the past. First would be to acquire a old bottle of nail polish from your wife/mother/daughter/girlfriend or an acquaintance who happens to be rather light on the loafers. Thin the nail polish down with some acetone until it's about the thickness of milk. Apply to the finished cartridges with a hypodermic syringe around the bullet and primer.
Or the second product that I've found to work well (and like better as it seems to hold up to oil as well as water) is "DyKem". DyKem is a metal working lay out die product that is available from anyone of a number of industrial supply stores. (Try www.mscdirect.com or www.grainger.com) Dykem comes in a transparent dark blue or transparent bright red. Apply as above with a hypodermic syringe.
Regards,
------------------ Abe
If everyone thought like me, I'd be a damn fool to think any differently!