back in the early 90s i shot side by side with jd, and his 50 sharps ,577 nitro at a range he took me and my buddy to, we shot the rugers open sights at steel gongs about 100 yards out, the 577 with the 750 grainers hit the gong which was about a 10 inch circle every time , very accurete big bore indeed, i have been following the 600 over kill and the 700 nitro for some time now, if memory serves me right theres a 12 gauge super shotgun shooting blown out 50 bmg cases over 1000 grains, but i think jd has them all beat with his 950 jdj shooting over 3400 grain bullet, look it up on his website its crazy, but as for jdj i think his shop is one of the best out there in craftsman ship he has done alot of work on some of my big boomers and his jd hard chrome and sob scope mounts are great.i always did buy and shoot the big bores from the 80s to about 2003, but now the go to gun for me is a 416 rem built on a sako action from jdj.i will leave anything over the 400 grain mark to you young guys to have fun with , not saying me being 45 yrs old is old lol. have fun with it and build your 50 alaskan you only go around once in this world.