Re: Federal "NT" .45 ACP brass?
I do not have a definate answer for you but thought I may give you a possible route to look at as far as what it was used for.
I'm wondering if it was not originally used for "non-toxic" primers that are used in frangible training ammounition. I had done a little searching about frangible ammo last year. It seems as though most of the frangible is used in indoor ranges at close range on steel targets. Many comments can be found about poor primer performance (i.e. ignition). I could imagine that a larger flash hole may have been a posible remedy to improve this.
If you have a bunch of them say 50 or more, I would be interested in them for use with X-ring rubber bullets. PM me if you wanna get rid of them.
FYI...X-ring bullets are primer powered, you modify the case by drilling the flash hole oversize. They also reccomend filing a notch in the rim for identification so they are not mistakenly ever loaded for normal use. A cardboard box with 3 or 4 old towels draped over some dowell rods set in "v" notches cut in the top act as a bullet catcher. Tape your target on the front.
I used some old dish towels and they will penetrate the first 2 towels most of the time(4 thicknesses). I would not use them to scare off the nieghbors cat unless you have a shovel handy. I absolutly would never want to be shot with one of these.
The bullets are reusable and can be cleaned up if needed with a little Armor All. A box of 50 are under $8-$10. A decapper die and a lee priming tool are the only tools needed to load them up.
They will not cycle a semi auto and will have to be loaded singly. I do not shoot these in the house but I do shoot them in the garage from time to time. They are very accurate, and a useful training tool.
Sorry to get of track.
Hope this helps.