If all you have is the turkey choke, definitely no steel or slugs as you mentioned.
I can't say about the specific constriction of your choke, but generally the factory turkey choke is not as tight a choke as you can get. In my specific case, I found I could go .020 thousandths tighter on constriction and have shot 00 to #4 buck through it and tungsten T, bismuth B, copper plated BB, and 3 sizes of turkey shot. But without knowing the constriction and being able to compare it with others I wouldn't suggest shooting larger shot like the buckshot.