Don’t know that I would post about taking it over there on an open forum…I took a Bakail double rifle 45-70 opened up to 45-90 over for my safari operator. Technically I owned it but only briefly. Never shot the thing. Also had a couple boxes of brass and 45-90 dies in my checked bag for him. On the plane I did some research and found that yes, many others had opened those guns up. But everyone cautioned that 45-90 should not be loaded above 45-70 max pressure in those guns. So what is the advantage? Very little apparently. A bit more range which presumably translates to more velocity per unit of pressure which presumably also means slightly more penetration at close range? Given the difficulty finding 45-90 brass I don't think the slight advantage outweighed the disadvantages. I presume one could still shoot 45-70 in it? But with that kind of jump to lands probably not very effectively.