Thanks, Tikka.
Surehuntsalot, No... Haven't bought a choke yet but picked up a factory full choke for $15.00.
It has a modified choke in it now and my 6 year old shooter isn't having any issues killing a paper turkey target at 20-30 yards shooting 2 3/4 dove loads.
I looked at pics of remington chokes and they look like the same spacing to the threads as the factory choke but you're not the first person who has brought up the strange aftermarket fit issues. With that said and after talking to a member on here and the Georgia GON forum, I'm not as worried about a aftermarket choke anymore.
I have some TSS shells in route. My plan is to see how the run out of the modified and full factory choke. I think either of those chokes paired w TSS is going to be the ticket with my son in a blind over a decoy and the shotgun clamped to a tripod for a 25 yard shot.