I will go along with the -buy two boxes of factory ammo- crowd.
I am not a fan of unknown, once fired brass. It's true, 270 should have been shot in a good chamber, but after all, the 270 has been around for eighty plus years.
You shouldn't ruin the brass with starting out reloading, if you take your time and follow a proper procedure.
Also, with your factory ammo, make two or three, five shot groups at 100 yards, using the best rest you can get. Don't let the barrel cool off between shots, just normal, slow fire. Let it cool between groups.
What the groups look like will determine the condition of your new rifle. If you are lucky, the five shots may make a round group, of maybe 1 to 1½ inches.
If you are unlucky, the bullets may walk, with the last one hitting three plus inches, often higher, than the first.
If this happens, have your rifle bedded, before you waste more ammo on it.