I have been up to the Red River a few times lately trying catch some carp or buffalo. I chum with range cubes then use corn or grain pellets on the end of a hair rig. Nothing!

I see them surfacing all around my bait. Not sure if I should sit on the shallow side and cast deep or vice versa?
Are they certain structure areas in river that are better?

Any help from you pros would be appreciated!

The only suggestion I have is to look for slough where the water slows down and pools up. Hopefully some other more experienced river fisherman will chime in

Can you post a pic of your rig? Also, are they right on top of your chum?

Here is my rig. They are not necessarily right on top, but all around it

shorten the leader between the hook and the swivel to about 6" and make sure the "hair" comes off the top of the hook

+1
I like to make enough wraps around the hook length where it ends directly across from the point of the hook

Here is one of mine

I think yours should do OK. Do the crashing fish seem to be reacting to your bait or are they just crashing? Whenever I fished rivers I tried to fish a slow moving deep pool or eddy when the river was moving slow and when the river is really flowing stay in the slack water eddies near the shore.

They seem to just be crashing. The part of the river where I am fishing has very little current.

I've had many night with crashing fish all over my swim but never got a take. Sometimes fish just don't mause sense.

We've had real good luck on the Oklahoma side fly fishing in the calm pools (as previously mentioned) near the big rocks. There are lots of big buffalo tailing and sucking back in those areas. They are in the current also but we have not been successful in keeping a fly in the zone in the current.

Scotts right.Shorten the length and make sure it comes off the top of the hook.If you are fishing single baits then shorten the hair also.You dont need lots of space between the bait and the hook.

Drill a hole in a couple of range cubes and thread 'em on your mainline. That way you wave a good chum stream comming directly from your rig. Stick a piece of corn with some foam on the hair. You need to get the hook bait to pop up off the bottom without floating the whole hook. It works in every Texas river I've fished. Might need a bigger weight too do it doesn't go bouncing down stream.

what does the hair do exactly?

You put the hook bait on the hair instead of the hook to give maximum potential to hook up when your bait has been received.