As we've seen, he obviously used guns but he is also morally against guns, and tremendously psychologically against guns.
Neal Adams: People looked at some of the first illustrations I did on this comic, and they saw that Batman had guns in his hands, and they said, "Aaah! Batman has guns? How can Neal do that? It's outrageous! He's going to ruin Batman!"
Now, I wish I could go to them and tap them on the shoulder and say, "No, Batman did, in the history of Batman, have guns in his hand, but within a very short time, he got rid of them. So has it ever occurred to you why he did that? Why he got rid of them?" I would think, probably, the reason he had guns in his hands when he was starting out is because he thought that's what crime fighters did, which is very logical and sensible. So then the next question would be, could he effectively use them? And I don't think he could, because his parents were killed with a gun. Even if he were morally against it, which we all believe, wouldn't he be tremendously psychologically against it?
http://www.newsarama.com/comics/neal-adams-batman-odyssey-100409.html
There isn't just one version of Batman. There are radically different versions of Batman with radically different aspects of character. The guns and killing were censored out of the New Earth DCU version of Batman's history. This Odyssey Batman is obviously a different version of Batman, obviously closer and more authentic to the original Batman creators Bill Finger and Bob Kane created who used guns.
The guns here shouldn't concern you unless you can only acknowledge and accept and enjoy one version of Batman, the New Earth DCU Bruce Wayne Grant Morrison is writing, and if that's the case then you are not likely to enjoy Neal Adams' Batman: Odyssey.