If it's new it should have included a manual that will tell you what kind of projectiles and powder you can use in it. If it isn't new it wouldn't hurt to write Remington and request a copy of the manual.
I'd be extremely surprised if they recommend against using the pellets, though. A different question to ask is whether or not your game laws allow the use of pellets. Here in Colorado they do not.
Jim Zumbo, Craig Boddington, Ron Spomer and Wayne Van Zwoll are all solid contributers to the modern hunting literature. Through their gifts (both hunting and writing) they make us better hunters. Whether it is letting us learn from their mistakes or by teaching us new techniques,they help us harvest more game. But I suggest looking to the oldies, the fathers of the outdoor writing craft, to learn tricks that you might have not used.
I chose to shoot the 270 winchester because I grew up...