You are on target Mitch, as to the stock and forend design. Whelen/NRA suggested that the forend be a bit beefier for recoil handling.
A German named Gerlich I think got to Winchester about 1934 as they were puzzling over a design to incorporate the best features
of lever actions they were to discontinue. The large variety of cartridges in the 1886 was a factor. Gerlich influenced the design team, as they settled
on the new 34 later 348 WCF caliber-and in the first couple of years one could get a 33WCF or 45-70 GOVT chambering. Winchester settled on the M-71 design that closely resembled the 86 but with special order features like the half magazine and pistol grip. This was still the depression era, and Winchester felt it like other manufacturers.
Pre-WWII, Winchester made every effort to still satisfy the customer-as George Madis points out in his books.
I can't help but wonder if someone might have prevailed upon Winchester to chamber the M-71 in 45-90 for a few rifles.
That would have filled a gap in smokeless loadings and power.
Going back to our topic: Originally, as much as the M-71 short rifle or carbine has become sought after by collectors, I think the
shorter barrel lacks rifle balance necessary for smooth slick handling as compared to the full length 24 in barrel version.
I have not tested my theory, as the 20 inch standard weight barrel M-71 is scarce and I do not own one,
My 22 inch medium heavy barrel 450 offers no cycling issues, so it is possible that the pistol grip and curved lever take up
the cycling angle force and re-chambering well enough for a fast slick action.
