Anyone else here shoot a '86 clone conversion or an original Winchester?

My guns will take a 2.80" OAL but nothing more through the loading gate. So I have always used the original 300g HV Winchestr load and a duplicate bullet. Wondered if anyone has a heavier bullet with a appropriate placed crimp groove that keeps OAL in check that they use?

I use the IMR3031 Load 300 Gr

RDB,
I have written records on all my .45-90 loads using several bullets and will check them when I get to the farm this weekend to see if any of them may be of use to you. One likely possibility is the 300 grain Nosler partition protected point, which I have used with devasting results on several sizes of game. These may be the same col as your 300 grain cast flat point solids and would therefore give you an easy 2200 fps in your 1886. The Beartooth 300 grain gas checked cast bullets for the .45-70/90 should also have the same COL and can stand speeds up to 2600 fps.
Some fun, eh?

Originals have a slow twist of about one in 36 so probably won't stabilize heavier bullets. I don't know about the new ones.

dpcd,
My Miroku Winchester 26" .45-90 has a twist that is 20-22" . I measured it somany times that I forgot which, but it does stabilize bullets from 300 grain cast GC and Nosler 300 g partition PP to (so far) 405g Beartooth cast gas check,405g Kodiak JSP, 450 gr Kodiak FP FMJ, NF 450g FPS, and Belt Mountain Punch 430 and 450g FPS. I have fired .45-90 sharps 500 grain soft lead cowboy action loads, but they were slow and did not group well.

I have the 45-70 Miroku with a 20 or 22 inch twist (like you, I can't remember but I measured it once upon a time) and I assumed they didn't bother making original spec barrels for the 45-90s. Which is actually a good thing. Mine shoots 400 grainers perfectly.