it wasn't so much that the revolver was indestructible-- it was more likely that the barrels got torched and could be quickly, easily and not so costly replaced.
While that may have played a small part in it, it really was the robustness of the inner workings that played the major part of it.
Matches back then were two days long - Saturday and Sunday.
The gun had to work with no repairs or modifications allowed for the whole two days.
For production class, the gun had to literally fit inside a special box & it had to sell under a certain price.
Small refinements to the locks were allowed, but, no real custom creations.
The 200 meter Ram targets have a "sweet spot" about 8"x 8" on the top where a hit will produce a fall - if the slug has enough oomph.
Inside, the Dans are more like the Ruger. Matter of fact, I permanently loaned my friend Jim, who's a Ruger only kinda guy, my old Monsoon Dan .22lr. He commented how alike the two are & I agree.
That greater internal strength is what made them hold up enough to maintain the level of accuracy needed to hit that "sweet spot".
I've mentioned this before and I haven't gotten around to it yet, but, I probably will before too much longer.
I believe I might have some of the old magazines I had back from those early times were all the news is on the Dans. I think they are down in the basement. I've only been putting off the job of finishing the basement since 1986, and now that I've been retired 5 years, my wife is bugging me again about it. If I run across them, I post something here about it. Maybe someone wants them.