I just picked up a cartridge in a lot of ammo that I cant identify. It is a rimless, belted case, 3" long. The bullet diameter measures .690" just in front of the case. The case in front of the belt measures .760". The case head measures .800". The headstamp is TZZ, with the number 90. Any help in identifying this round would be appreciated.

Sounds like an artillery sub-cal or spotter cartridge to me . Cant find anything with those measurements in my referances , but I dont have much on artillery type cartridges.

Apart from the case appearing to be Israeli in origin , my suggestion is ask Tony Williams, or check out his site , mentioned elsewhere on this forum.

Very odd. I can't find any reference to such a cartridge (and I have very good references!). I agree that it's probably a spotter of some kind, these have never been properly referenced.

Could you post a picture of it? I'd like to see what the bullet looks like.

Tony Williams: Military gun and ammunition website and Discussion forum

Thanks for the input. Someone else suggested that it may be a wildcat based on the 50 BMG with the belt turned onto the case. The belt isn't very sharp, so they may be correct. I'd post a pic, but not sure how to do it on here.

I did notice that the rim diameter is the same as the .50 Browning, but the body diameter is different.

Tony Williams: Military gun and ammunition website and Discussion forum

I've looked through my military references without success. The headstamp corresponds to some .50 BMG which I've seen. I also suspect it could be a wildcat or simply one of those rounds one finds from time to time which was fabricated by someone with too much time on their hands.