Most of mine go bareback.
But, I do check the quality of ANY covers I find on clearance and the dimensions. I don't worry about the exact shape. Use a really nice gasser cover I bought for, maybe, $10 on my SSP. I have a big one for some maybe an Akorn komodo style thing that seems big enough for a 26, but I haven't tried it out there. Had it on a 22 WSM for a while & it was plenty loose.