I don't think it is much meant to be innovative. Just practical, i.e. to get the max "big bore" from a nearly unmodified P-14.

As far as that goes it seems right.

I'm not sure, but I think the JDJ/.444 Marlin rounds require a bit of trickery to the P-14 action rails to get 100% feed reliability. Personally, I found enough trouble making .303 cal P-14's feed flawlessly that I think ANYTHING that keeps trouble to a minimum is an inherent good.

The P-14 was a cobble job originally meant for a rimless round, and should have been left as such IMO. I've owned 3 or 4 that were really herkyjerky and read of many more ditto. I do believe the sniper mod rifles were worked over pretty hard to ensure feeding of the .303 round. All my .30-07 M1917's fed flawlessly from the gitgo.

The P-14 is accurate as all-getout tho. Really fine shooters.

Anyway, that P-14 should hold 5 of those weirdo .416 rounds and if it was me I'd chop the barrel back to 18 inches and have the finest hound hunting rifle for our black bear ever made.

I like it, even with the longer tube!