The Arminius revolvers were made by a West German company (back when there were two Germanys, ours and theirs) named Hermann Weirauch. People have mostly forgotten, but from the 1950's to the late 1970's, West Germany was a big producer of inexpensive pistols, largely revolvers. They ranged from awful (some of the RG's) to good value for the money, like your Arminius.
However, they were inexpensive, and they were not as durable as a more expensive gun, They were mostly made out of precision cast zinc alloy. The designs took account of that, but it just isn't as durable as steel. For low-powered cartridges, like 22 rimfire or 32 S&W Long, it is OK.
I have an Arminius in 32 Long (32 Long revolvers with target sights were hard to come by) and it's a decent gun. And I had a friend with one in 22, and that was OK too. But 38 Special is a different ballgame, and I have no experience with them in that caliber.
I would assume that if is in good shape, lightly used and well cared for, it would work OK. But with heavy use or neglect, a zinc gun is going to wear out sooner than a steel one, or even an aluminum alloy one.
So basically, we'd need to know more about your gun to tell you much, and even then, many people have a low opinion of these West German revolvers as a class. Like I said, they tended to be built down to a price rather than up to a standard.