This is what type of turkey shoot? The site is not very specific about rifle types.
This is from the site
For those of you who have not competed in this particular event before, you may find the following helpful information before arriving at shoot.
RIFLE
The rifle may be either flint or percussion ignition, of either the traditional hunting or traditional target type, with no limit as to weight or caliber. The rifle may not be equipped with a false muzzle. No in-line actions, thumbhole stocks will be allowed.
FRONT SIGHT
The front sight may be a blade, pin-head, post or barleycorn. The use of Shaders is permitted.
Rear sights
All rear open sights must be at least six inches forward of the breech end of the barrel. They must have a U, V, or rectangular opening, as wide at the top as any part of the notch. Adjustable rear open sights have in the past and will continue to be permitted. However, no adjustment may be made to the sites after the beginning of the competition. And adjustment screws should be covered with either wax or tape. The use of Shaders is permitted.
Chunk
There should be nothing that would confine the rifle, in place on top of the chunk. For instance, if you use a sandbag should move freely on top of the chunk. If you're using a cant block affixed to your rifle, it should be able to move freely on top of the chunk