Hitting off the toe

I've noticed that with my longer irons, (5 up), I seem to be hitting off the toe end, or off centre toward the toe end. If I line the ball up at address to quite a bit to the left of centre of the club head, I hit the ball off the centre.

What am I doing in my backswing to cause this and why doesn't it happen with the short irons?

I've noticed that some of the pro's move the clubhead, especially with the driver, so that the ball is lined up left of centre.

This is quite normal. Get someone to check your actual alignment by standing over the ball to tell you where you are actually aligned. Because you are getting farther away, you look at a different angle, not the true angle. Try this: align the ball with the middle of the club face from over top of the club. Now, take a couple steps back - the ball will appear to be aligned more towards the heel. It could be nothing more that your eyes playing tricks.

That's inspired!! I never even considered that. My eyes are pretty ropey, so you may be right. I'll give it a try, thanks.

You really see this with long drive contestants. They think they are aligned with the center of the clubface, yet the ball is lined up on the toe. They have to line up to what appears to be the heel, some are even lined up with, from their position, the hosel to get aligned to the center of the clubface.