Is IMR still producing SR4756? Have not seen it available for awhile and have heard they are discontinuing some powders. I've used it in 9mm but never tried it in shotguns.
No...it's no longer being produced; Hodgdon, in it's infinite wisdom, decided to do away with PB, 7625, and 4756. I started looking for powder when I heard the news, but I think that they D/Cd it a LONG time ago and just didn't bother to tell anyone.
4756 is (was) a great powder!!! I used it in 9mm, 38 special, 38 Super, and several shotshell loads in 12 & 16 gauge, most notably in nontoxic loads.
Now the bean counters at Hodgdon are trying to force "their" powders on us....Longshot, HS6, etc. Wouldn't mind too much....except that they don't put put a lot of data for slugs, nontoxic, ect. I do think I have found a promising replacement using Federal hulls and 800-X, but a little more testing needs to be done.