What are you planning to shoot with your 270? The Winchester 150gr Power Point is widely considered a great load for the money. Should be more than ample for deer.
If you want a really potent load check out the Federal High Energy cartridges. They are spendy, but they come in two versions, a 150gr Sierra Game King or a 140gr Trophy Bonded Bear Claw. How does almost 2000 ft/lbs of energy at 300yds sound to you? We chronographed the 140gr at 3300fps at the muzzle. Gonna use this load on moose in a couple of weeks. If the moose gods are smiling on us we'll let you know how it worked.
I would say the 270 is fine for moose. My cousin/hunting partner shot two moose with his this year. The first, a bull was at 80 yds, the second, a cow was 400. His first shoot went through both lungs. He was shooting 150 gr Partitions that I loaded up at 2650 fps. I am only SLIGHTLY jealous.
There can be too much of a good thing with antler rattling.
I like to hit the horns together for a good 30- to 40-second rattling sequence and then hang them up and resist the urge to hit them again.
This works to the hunter's advantage, because if a buck has heard it, he may have been 300 or 400 yards away and he comes in and he's not exactly sure where it came from.
When finally is time to rattle again throw a slight change-up into the routine.
The second time, don't rattle as loud...