M-14 Olin Mathieson Magazine?

[MP Freeman]

I went to the Indy 1500 Gun Show today and bought two 20-round mags for my M1A. They were new from factory and still in the original packaging. Here's what is on the outside:

Magazine Assembly
1 EA
Brunswick Sports Products Co.
Olin Mathieson Chemical Corp.
A-IC
Apr 62

Is this a rare magazine? I've never heard of Olin Mathieson before, and I would like to know more about it before or if I open the package. Thanks.

 

[ctl]

"OM" mags are fairly common. they are one of the 5 or 6 main USGI mag mfrs you find. I have a few NIW OM's myself.