Well, Hunter Arms made ONE 14 gauge Grade O gun (which grade gun yours might be, can't tell from your photos?), but if a 12 gauge shell won't fit and a 16 gauge shell is loose; then 14 gauge is the only shell size remaining between the 12 and 16 gauge bore sizes. Now for whatever this information is worth, that 14 gauge L.C. Smith has never been located; but when, or if it is, it will generate some serious collector interest. In all honesty, it'd really be a freaky thing if this gun were that lost 14-bore; but I suggest you have a gunsmith double check those chambers and let us know what you find, as that will be the only way to resolve this mystery.