Who can tell me what this case is?

[ICANHITHIMMAN]

So long story short this case was part of an estate sale. I got about 20 loaded rounds and the rifles. There was no rifle for this round and I dont know what it is? Im asking for your help here are the specs and a photo of it next to a once fired LC 223.

The case is formed from Federal 223 and had a 22cal bullet seated in it.
COAL is 1.400
Base to bottom of neck is 1.220
Base to start of shoulder is 1.085
Neck is 0.185 in hight
Shoulder is the same angle as 223 at 46 degrees

 

[ewallace]

It is most likely a 221 fireball case that has been formed from 223 brass

 

[ewallace]

 

[ICANHITHIMMAN]

ok that seam's to fit the spec's thank you 221 fireball I will do some reading up on it.

Thank you