(1) You are WAY over-crimped. Anyone who tells you simply to crimp more to solve a feeding problem isn't someone to take advice from. And anyone who talks to you about crimping without talking actual measurements isn't someone to listen to.
(2) Some bullet / gun combos have an OAL that is technically neither too long nor too short where the bullet occasionally will jam on the barrel hood during feeding. The solution is to lengthen or shorten. One case I had with a Blue Bullet 125gr RN, a difference of .01 longer or short eliminated the issue completely.
(3) Some times the extractor isn't moving as freely as it should and will restrict the freedom of the cartridge to twist around as it would like while feeding, causing a feeding jam. The solution it to remove the extractor, clean it and everything it touches, lube it, and reinstall it.
If I were in your shoes, I would:
Remove, clean, and re-lube my extractor
Adjust taper-crimp to .377 or .378 for the time being, then go back to it later, re-read, and determine optimum from scratch (or leave it alone at .377 or .378 -- it won't make a difference)
Recognize the OAL anyone else loads at is irrelevant to me
Determine my maximum OAL by a method opposite of yours: Size a case, no primer, no powder, seat a bullet too long, then seat shorter and shorter until it plunks and spins freely. If your adjustments to seat deeper are incrementally small enough, it will literally go from doesn't spin, to spins with a lot of drag, to spin with a little drag, to spins with a hair of drag, to spins with no drag, and THAT is your MAX OAL. Then load shorter than that.
ALSO -- Plated bullets are only a hair cheaper than jacketed while being of lower quality. And plated bullets are not even of the quality of good coated lead while being more expensive, so consider a switch to coated or jacketed. And while I am on my soapbox -- 147gr bullets are not getting you the advantages that action shooting "wisdom" would have you believe, so consider a drop to 124/125gr. Easiest path you can take is jacketed 124gr. Coated lead takes a little more doing, but no more than the plated you are already working with, and you are likely to get better accuracy for less money, AND they look cooler.