I have not done it yet. But I plan on it.
I am familiar with the case head variations in pressure, and was hoping someone would bring this up.
Again, I'm not advocating anything which may put stress on a firearm or shooter, as it may be.
However, only, I am trying to get some collective juices flowing on the subject, and find out some of the reasons as to why this does that and so forth.
One thing I found odd today while looking through my (old) NRA load book, is a pressure of 49000-something for a high end 45-70 load for modern single shots.
The thing which struck me is that that surpasses the .450 Nitro.
But thats not the end of it.
They have the same case head.
I do believe in the handi's being overstressed, and as mentioned in another thread, a 300 mag did it, but however, the 300 works at MUCH higher pressure than the 450 or this high end 45-70.
Anything over 50000CUP is too much for the handi in my opinion, and the 300 mag passed that mark.
Neither the hot 45-70 or the 450 would come NEAR that 300 mag.
Odd true, but it is true.
There is one factor involved though and as you had mentioned, it is frame and lug stress, etc.
I am neither going to be testing any of this myself, and do not advise differing from the load books, but if somehow, it helps in understanding the handi, I'll keep studying.
I'm using black powder eqv. loads now with 4198, and have no need to go any higher, but keeping these thoughts in mind may help for any custom handis that may come into being.
If the occasion arrives when I need more than the handi, I'll grab the Kodiak I'm recieving soon, reamed to 450no.2.
But yes, I think this is why the handis will not hold magnums like 300 mag, etc, or any others.
But possibly CAN handle lower pressure, LARGE case capacity rounds.
After all, that hot 45-70, and I'm sure other hot 45-70s are passing the 450 by, with the same case head by about 1500-2000 cup.
Just thoughts.
Fun to think of, but not to try at home sort of stuff.
I just do not think the frame is strong enough.
And if it IS, then it's just borderline, just like the hot 45-70's.
Me, I'll stick with black-eqv. loads cause I don't need more at this time.
Fun stuff to think of though.
D