How do you tell if your Remminton 7400 in 270 is long or short action?

To determine if your Remington 7400 in .270 is long or short action, check the cartridge length it is designed for. The .270 Winchester is a long-action cartridge, so if your 7400 is chambered for .270, it is long action. Additionally, you can look at the overall length of the magazine and the receiver; long-action rifles typically have a longer magazine and receiver compared to short-action models.