I sent him to find ammo and he still hasn't come back to me, is this a bug or something? Can i find him at a certain place or something?

It would be nice to know where he is lol... Thanks in advance.

There's a lot of posts about Dogmeat like this one but I'll answer anyways. I sent him to find me a weapon and he never returned I was probably about level six and now I'm level 18, (probably about 10 hours of gameplay) suddenly on the main quest (not sure if it triggered him or not) but I got a message at the bottom of the screen saying that he was waiting at vault 101 for me. I went there and sure enough there he was, without a weapon but alive...So dogmeat is about as random as alot of the other stuff in this game.

Well that dog is strange... due to hime being worthless and get killed by most things i told him to wait for me, in my home in megaton, then suddenly in the middle of a main quest he stood there in an underground tunnel growling at my enemies, he spawned in behind me when i changed area... strange

I found dog meat to be very handy especially while wandering.

He growls and points in the direction of the enemy, which is very handy especially at night.

He sometimes doesnt attack and lets me do the killing, although he did once charge at about 6 super mutants without as much as a growl, just bolted, I ran after him right into them, Needless to say he died, had to re-load , (dont like loosing him)

I reckon due to AI pathing for him (he cant jump) he does tend to go the longest way possible sometime to places while following you, especially in the mountains etc.

On the go fetch line I tend to run after him, but in generall never really done it much as I normally got loads of ammo due to my wandering fool mentallity hehe .

Just make sure he gets stimpacks when needed and you tell he he is a "good dog" seems to keep him happy