Reilly advertised rifle barrel lengths in the 1860's as 24," 26", 28".
I thought this gun might have been a rifle because of its weight. George L.'s 4 bore weighed in at 16 lbs. However, most Reilly rifles had pistol grip stocks. About half his extant big bore shotguns (10 gauge and larger) also had pistol grip stocks. His shotguns 12 gauge and smaller never did; all extent 12 ga shotguns are straight stocks. So I concluded that the barrels were original and perhaps it was just a big gun and that the user ordered the safeties.
There are two extent Reilly shotguns in the database with a stalking safety or variant:
. . .1) 14985: 16 gauge now owned by SXS40. The barrels are 28", a Reilly rifle length but they could have been shortened; the safeties have been removed. The weight is not in the ad which would be a dead give-away; but it has a straight stock so it's a toss up - original rifle (no because of stock); or shotgun (no because of barrel length and safeties)? The weight of the gun will decide the issue (HWK sir, please add).
. . .2) 15625: George L's 4 bore - he insisted it was created as a shotgun, not a rifle; I think it was decided that this gun began life as a 6 or 8 bore shotgun and the chambers were bored out for paper 4 bore cartridges.
1) ===========Terry Buffum now owned by SXS40=========================
14985. (original pin-fire altered to centerfire)http://www.amoskeagauction.com/109/717.php
serial #14985, 16 ga, 28" matted rib damascus barrels choked cylinder and cylinder with very good bright bores having a few light pits present. ; unfortunately the stalking safeties are not present.
2) ===========George L's 4 bore========================================
15625. (original pin-fire altered to centerfire)https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=594726&page=1
I think the Reilly big-bore shotguns in the 1860's-70's broke the rules and used more rifle technologies. .probably for obvious reasons.