Remington 870 Magnum

Question
Can I install a slug barrel that indicates it fits 870 Wingmaster, 870 Special Purpose, and 870 Express  on the above mentioned model the Remington 870 Magnum.  The barrel seems to fit however the slide action does not work as smoothly as with the original barrel attached. Thank-you

Answer
I can't tell you for certain without physically examining it, but the answer should be "Yes." It seems strange to me, however that the slide should work any different, which gives me some hesitation. If you do such an installation, use ammunition specified on the barrel.