What is this tool?

[abbyonheyward]

Hoping you guys can help identify this tool. I recently acquired quite a bit of vintage (1960s-70s) reloading equipment. The tool pictured was in the lot. Any idea what it is?
Thanks, in advance, for your help.

 

[abbyonheyward]

A couple more photos.
Thanks

 

[rockquarry]

I bought one of those years ago for some type of military gun, I think. Never used it, still have it. Have no idea what it is. Pretty much got rid of all the military-type guns.

 

[Mrnurse]

Its a M1 carbine piston collar spanner wrench...has nothing to do with reloading.

 

[abbyonheyward]

Thanks for the information. I sincerely appreciate it.

 

[rockquarry]

Its a M1 carbine piston collar spanner wrench...has nothing to do with reloading.

Thank you, Mrnurse- I had a couple of M1 carbines; got rid of both about ten years ago. At one point, I guess I thought I really needed that tool so I bought one. Not the first time I've made a needless purchase.

 

[Alk8944]

It is correctly a "gas piston nut wrench" for the M1 Carbine series.

 

[DWalt]

It is indeed an M1 carbine piston nut wrench. I have one, never needed to use it. I have been cautioned that the piston nut should never be removed unless you have a new replacement nut. I came up with a way to clean the piston area very well without removing the nut and tappet. You need a fairly strong small magnet.

 

[daboone]

I've also read that over tightening that nut can crack the housing which would seriously suck.

 

[Mrnurse]

I fooled with them for awhile, the Piston collar should be torqued, and punch peened at 2 points... the piston collar quickly vibrates loose in a M2 Carbine.