Read the frame strength page in the FAQs, the 270 was available in 1993, but as John said, they won't fit any high pressure accessory barrels to frames made before 2000, but they will replace a barrel on an original 270 rifle if it were defective, no other high pressure accessory barrels tho. But you can fit one if you want, it's more of a liability thing for them since they are pre-Marlin who9 bought H&R1871 in 2000, you aren't going to experience a catastrophic failure.

Tim