Buckshot loads with Unique powder

[30calshooter]

Anyone load buckshot with Unique powder? I'm not interested in high velocity hunting loads, just some low recoil 12 ga loads that I can have fun with at the local gun club range. I've seen YouTube videos by FortuneCookie45LC where he loaded the Lyman 525 slugs in 12 ga under 20-21 gr. unique and had good results, but I've not found anything on loading buckshot with Unique.

[FullTang]

Anyone load buckshot with Unique powder? I'm not interested in high velocity hunting loads, just some low recoil 12 ga loads that I can have fun with at the local gun club range. I've seen YouTube videos by FortuneCookie45LC where he loaded the Lyman 525 slugs in 12 ga under 20-21 gr. unique and had good results, but I've not found anything on loading buckshot with Unique.

I've used Unique plenty of times in good-performing buckshot loads. You're right that there isn't much load data out there, so you have to feel comfortable with at least a little wildcatting. My basic approach is to find a regular shot load (pretty much always 1 1/8 for Unique) that has fairly low pressure (well under 10K psi) as a starting point. Of course, buckshot takes up way more room than bird shot, so stack height is an issue. One solution is to use the load as is, accepting a higher stack height, but roll crimp with an overshot card---this will usually give you plenty of room and a roll crimp almost always lowers pressure compared to a fold crimp. The other way to accomplish something similar is to use the next largest wad size; so, the BP Manual lists a 1 1/8 oz #8 shot load with 25 grains of Unique in a Fiocchi hull, with a Fiocchi primer, using a PT1210 wad (I really like PT wads, and have the whole range). This generates 1280 fps and 8800 psi. I subbed in a slightly higher-cap but similar construction PT1215 wad and weighed out 1 1/8 oz of #3 buckshot that I had on hand (can't remember the exact number, but I think this is 20 or 21---depends on the shot). It fit just fine, crimped nicely. This probably raised pressure a small amount, because of the shorter cushion section on the wad, but this particular load probably benefited from a little extra pressure, and it shot great.
Many people will advise against this, but rigorous studies by others have shown that wad substitutions like this change pressure surprisingly little, as long as it's the same type/brand of wad. Switching to a completely different style of wad can have major effects, however. Don't do that! So, going from a Fed 12S3 to a 12S4 with the same payload will increase pressure slightly, but going from a WT12 wad in a Remington hull to a PT1215 in the same hull can cause a huge pressure spike, because of the radically different wad construction.
In any case, that's how I do it, and I've done this same basic thing many times with various combinations, with uniformly great results. I'm usually cautious enough that my loads are a little slower than I'd expected (when I get the Chrony going), but I'm also mostly looking for training/plinking rounds, so it's OK.

[megasupermagnum]

Substituting buckshot in lead shot data is fine, many loading manuals encourage this practice. FullTang's method is a very common one. Instead of a Winchester AA, use a Winchester AAF114 wad. You don't always need to do this. With smaller shot like 4 buck, it might just fit as-is. Especially the Winchester style wads, they will compress really easily to small changes in the load height. If you cut the petals off your wads, that usually gives you enough room to fit even large 00 buck size with no other changes.