A rifle is normally meant to be a more precise bullet delivery system than the typical handgun. DA or DAO is not the most accuracy producing method of firing. DAO rifle would defeat the primary purpose/advantage of using a rifle. IIRC, there were some "police type" shotguns that had a DA(ish) trigger pull so the fuzzies didn't get confused and light off their shotgun prematurely.
BTW "Revolverish" rifles were an expedient solution to a production issue of the late 1800's and were neither effective nor prudent(just my opinion).