In my collection of .45 ACP cases I have one made by Federal with “NT” in the headstamp. I understand that this refers to a “Non-Toxic” primer mixture for use at indoor pistol ranges. I read on another forum about a similar .45 ACP cartridge case made by Winchester, also with “NT” in the headstamp. Both cases have a small diameter primer. Why is this? Is it an odd size to prevent reloading, or does it have to do with the composition of the primer mix? Who else makes this “NT” type load?