NC/NM = non-corrosive/non-mercuric and that makes them plenty modern. Chootum!
It was Infallable, we know it today as Unique. /https://www.castpics.net/subsite2/GeneralReference/L&R-Smokeless.pdf Page 13.Hercules has a container of Bullseye in a lab where they test it every year.
That Bullseye powder is over 100 years old and is just as good as new production of today!
Yes, gun powder lasts a very long time.
We made a cannon to shoot golf balls one year at 4th of July. We buried it except for 2" sticking out of the ground. That way if it blew up we didn't get hurt.I looked around and tried to locate the rest of it, when I looked at the house I could see a hole in the siding about 6" away from a 15'x20' picture window.
The next day I found pieces of it imbedded in the wooden fence 375 yards away!
FOUR!!!It was Infallable, we know it today as Unique. /https://www.castpics.net/subsite2/GeneralReference/L&R-Smokeless.pdf Page 13.
The Bullseye we use today has not had it's formula changed since it was first made for retail sale, in I think 1899, and was labeled Bullseye #2, just known as Bullseye today.
Edit to add: Unique has been reformulated twice over the years in an effort to clean it up, supposedly minor changes.
It's stored under water to keep the air off of it or it would have gone bad in a few short years.
We made a cannon to shoot golf balls one year at 4th of July. We buried it except for 2" sticking out of the ground. That way if it blew up we didn't get hurt.
We shot a 5 gallon bucket of golf balls out of it and thought they were only going to the other side of the woods across the valley.
It turned out they were coming down on a town 3 miles away.
Luckily no one got hurt.
We drove the rest of the cannon, 2" pipe, into the ground with a sledge and covered it up with a clod to grass to hide the evidence because the State police were still looking for the people that did this.
Didn't do that again!
It the don't smell bad shoot-em up. But if you do get rid of them those cans are collectable.I’ve removed the red cap on the 4227 to show the mouth of the can.
I have manuals from then but even a newer manual its the same as with any unknown . Start in the basement and work your way up..you can run a ladder test and use the minimum or even 10% below if you are worried. As long as the powder passes the sniff test and isn't polluted it will be fine.This raises another question. If this powder is from the 60's, what would the load data be for something of that era? Do they change formulations over the decades or would today's load data be the same for powder from previous decades?
I don't know...Finally, keep the cans whatever you do. You'd be surprised what the empty cans would bring on Ebay or similar. Vintage cans! Part of Americana! Put your powder in them(labeled on the bottom of course)! Helped to wn the west! (well part of advertising is exaggeration) Man Cave material! She Shak material! (well the times they are a'changin) All yours at a price that seems a lot(but not to me), but a value for such vintage items!