I definitely think it was mis-marked at the factory IF it is actually a M14. If so, that is kind of a specialty thing that some collectors would be really interested in. For me, years ago, I was attracted to the mis-marked Colt Diamondback revolvers, but the sellers were always asking a premium and I always passed. Even today they are not sought after.
I have both a 4" M17 and M18. Nice guns. The M18's tend to sell for a bit of a premium over the M17's which are typically 6". For just shooting, I prefer a 4". Been pretty pleased with the 3" and 5" M63's I have overall and they tend to be the ones I shoot now. I like the higher round count and most of the shooting is essentially plinking anyway these days.