Ammo ID, military, US?

Question raised on another forum.

These are UTM (Ultimate Training Munitions) man markers.
UTM is a UK company.

utmworldwide.com/

Thanks

Looks like 223 (5.56 NATO) Dummy cartridges ???
If European what caliber, 5.45x39mm Russian ?
Looks to thin a case for 7.62x39mm Russian.

These are 5.56x45.

They look strange because the “sleeve” has been partially pulled off the “base” and the “bullet” cannot be seen (fired or removed ??).

Those are not technical terms, BTW.

Ray

Ray these are just fired ones.
Bullet is gone and the case head with inner sleeve is telescoping back to move the unlocked breech (special UTM design for rimfire .22s) and make the gun cycle.

Here some more close ups:
utmworldwide.com/civilian-t … mmunition/

And a 3D scheme:
breachbangclear.com/wp-conte … -556_1.jpg

EOD

Thanks for that 3D drawing. Now I know what the parts are properly called.

I have a couple of complete ones and one that has been dis-assembled to show the working parts. So, what do you call the fired ones?? Empty cases?

Ray

Ray, I guess so but there might be different definitions by other people or even the manufacturer.
For example the forwad section here is called “slide” and the head section “body”. In fact it is the “body” sliding while the “slide” is not moving at all.

I noticed a similar debatable “vocabulary” when people do describe the function of fuze mechanizms (mainly artillery).
Means some people do describe parts (firing pins for example) of a fuze “in air” (after having been fired) as “moving forwards” while they in fact keep on moving due to inertia and the rest of the fuze (body) is being retarded/slowed down by the target material.
Same goes for safety collars which are then described as “moving backwards” upon firing. In fact they do rest in their position (set back) due to inertia while the rest of the fuze is being accelerated and moving forward.
One would wonder how often dis is disputed by people explaining fuze functioning.