There is a lot of difference between shooting a flushing quail and shooting a tom in his head/neck area. On flying birds you are “pointing” your barrel to get your shotstring to intercept a moving target down range. For a nearly/fully stationary turkey you are “aiming”.
I find that pointing is instinctual and snappy, while aiming is very deliberate, much more like shooting a single projectile down range. And remember to keep your cheek down on the stock as you carefully aim.
To get some idea of where you pellets are flying, you don’t have to get fancy with a store bought target. Get some cardboard and put a paper plate on the cardboard. (Making sure that you are shooting in a safe direction). In the middle of the plate you could even draw a turkey neck/head. Shoot at 15, 25 and 35 yards and count up how many pellets are in the paper plate/ on the bird outline. That should give you a good idea what your maximum range should be.
A.410 shot shell will not hold as many pellets as my 12 gauge gun will hold. The above recommended #9TSS makes a big difference because it is super dense and maintains down range knockdown power. One #9 shotshell will have a whole lot more pellets for the same weight compared to a larger size pellet size.
Be prepared for $$$ shock if you buy TSS. Perhaps 10x cost of a one of your current shell options.