Diana 34 shooting too low with open sights - ideas?

[Beeman22]

I recently bought a cheap Diana 34 as utility "beater" gun - basically, something that I could lend to friends without worrying about it. The gun has some pitting and scratches, but shoots well and with minimal twang, and the TO1 trigger is very nice. Problem is, the gun is shooting about 4" low at 10 meters with the rear sight adjusted all the way up. The gun is of an older (1991) vintage, so the front sight is an all-metal globe mounted on a dovetail, like a Weihrauch, and everything appears stock. I even tried pulling out the insert and replacing it with a shorter one, but to get the gun to shoot straight at 10M, I'd have to be just a tad above the bottom of the front globe.  What am I missing and any ideas on how to fix this? I did not want to scope this one.

[SteveP-52]

I can think of a couple thinks but set a straight edge on the breech block and see how bent the barrel is. Might well just be a matter
of bending it back up a bit to get things back in line.

[Roadworthy]

I'll go along with Steve's assessment.  Both sights are on the barrel itself so your problem may well be a slightly bent barrel, especially if the gun has been abused.  Force applied "over cocking" could have done it.  There is a barrel bending tool in the GTA library which I believe originally came from the charliedatuna.com website.  It's a pretty simple tool and gives you control over the bending process.