Along with all the mag combinations i keep one mag (140) with one round in my back pocket. When the "make ready" command happens i take the single mag-round and load it first. Press check that it loaded, then put a fresh mag in.
I'm using 115's with HS-6 in one Open gun. A little shorter slide-barrel combination. In my full size gun i use 124's and 7625. Both are tuned for the gun port combination.
The slide racker should be on the right side. But now you have to reach all the way across your gun to rack the slide if you have a jam. It's a toss up.