1.730-1.753 or so is normal, and no issue, whatsoever. Different manufacturers have their own theory why shorter is better than longer, and so its purpose made. Shorter brass, like Federal, can be shot and sized pretty much until it fails, and it will not need trimming. This is advantage to reloader.
Longer brass, may stretch and go over specification, thus needing trimming.
Also, in terms of manufacturing tolerances, this is wider than people understand. No manufacturer can make anything without variation. Variation in extremes can be wild. So it makes sense to set your length shorter, to make sure the "extreme" long pieces are still under specification, while the manufacturers that produce longer brass, may have some OVER specification. This is common in manufacturing across the globe. (this method) As you want to setup your machines to make something where the extremes are within specifications. So if you make something toward 1 end of specification, many will fall out, and will not pass, costing manufacturers TIME and MONEY to sort out.
Its far cheaper for manufacturer to make something where extremes are within Spec. Federal is being smart.
AR15's don't give a damn about brass length within spec. People often mistake what works in bolt guns apply to AR15's. This is not the case. AR15's are worlds more forgiving, looser tolerances, and not as precise/accurate.
