Taylor, when you adjust you powder charge, you are not looking for a specific velocity, you are seeking the best group size. Once you've completed this first step, then you adjust seating depth to further improve group size.
WT, you've been given the correct answer twice.
Seconds is for cosmetic blems only. This issue WILL AFFECT ACCURACY. (I know I've seen it on paper), and is not a cosmetic blem. If you pick up the phone and call the Noser Proshop they will make it right for you.
My last lot of Winchester brass was very inconsistent on it length. Some was so long they would not chamber properly, so I'd test your 3-4 longest before loading to make sure they will chamber first, if you plan to trim after your first firing.
Here's what I would load:
Win Brass
CCI 200 Primer
60.5gr H4831
magazine length
I have yet to see a decent .270 Win that will not shoot that load under an inch (with BT's)