That is quite good for getting use to a gun.
looking at the pictures of your back sight, I would have trouble with that I think.
Shooting bulls eye, i always held at 6 on the black center of a 25 yd target, but that is with adjustable sights, on my Hi Standards, and 1911.
These days I am shooting more combat guns and revolvers and do better with a center hold.
I also find I shoot better with just a plain sheet of paper with a small dot ( or the first shot ) in it, rather than look at a bunch of circles and what not.
But as you shoot the other stuff good, You will figure it out, I would be tempted to take a bit of black tape on the back sight to raise the bottom of the slot up, looks too deep to me.