It all depends on your setup
If you use an indexing head and a tailstock, it may be too short.
If you only do the occasional barrel like I do, here is the way I set it up.
Make 2 barrel vices and attach them to the bed of the mill. Pack the vices to get the bore parallel to the bed.
Make a carbboard disk about 3" in diameter, and mark radial lines on it such as 60 degrees if you are having 6 flutes. Cut a hole in it the same diameter as the barrel, and stick over barrel with duct tape, right up against the vice. Use this to do the indexing against the vice. It is plenty accurate enough for barrel fluting. I hope this makes sense.
Take it slow and use plenty of coolant.
Rob Carnell
Sydney, Australia
