I am will just be using my duck hunting gun, Remington 1187 sportsman. Currently it has a Patternmaster Extended Range choke on it. Will this work if I will be shooting Nitro Turkey Shots?

well theres only one way to find out......PATTERN IT!!!

shoot it at 25 yds...then back out to 40 yds. always pattern your gun with the shell your going to be hunting with

I was in your same boat, first time Turkey hunter but big time duck hunter & planning on using my 11-87 for Turkeys. I did not want to put new sights on the gun for Turkeys. Here are the two things I think you need to do. You need to know where your gun shoots, high, low, right, left. I grabbed some 1 ¼ steel duck loads & shot paper. Sit down & make some good shots & pay very close attention to front bead & center bead & or the rear part of the rib. Now you will know if you need to aim (high) at the eye ball or (low) the base of the neck to center the pattern where you want it to end up on Mr. Tom. Now you know where the shot is going & you saved a few dollars so now grab your Turkeys loads & see what loads gives you the best even pattern. I went with Hevi-13 2oz #6. Good luck