I am new to bowhunting and I was given a bow by my cousin. It's a PSE Thunder Flight Express. It was cranked up to 76lbs on the pull, but I had it cranked down to around 60 so I can practice on technique. It had a sight, arrow rest, quiver, stablizer...pretty much all that it needed I guess. But the sight had only two pins, and one of the pins broke so I had to remove it. So I bought a Cobra five pin sight from Bass Pro Shop, and I mounted it on the bow. Now before I was make groups from 15 yards in a two inch radius. So after mounting the new sight, I went out to dial it in, and I saw that I was shooting to the right. I adjusted it, and it moved the shot to the left, but it was still of my mark, so I moved it all the way over as much as I could and I am still off by at least a foot. I can't move my sight over any more. Any suggestions?
You need to check that the bow is in tune and shooting straight before setting the sights. You're arrows are probably not spined correctly for that draw weight. Take it to a good proshop and have it looked over.