In the fall and spring it's difficult to shave weight, because you need cold gear to be prepared for sudden weather changes. But in the summer, 50 lbs seems ~way~ too much. Makes me wonder what's in your pack...
50 miles is just an overnight hike at 25 miles/day. So you should be able to get that down to 20-25lbs during the summer, no problem. And 25 miles with a 25lb pack is entirely reasonable, even for an occational hiker in sub-average condition (like me).
For instance, on a summer overnight I don't carry a tent, stove, extra blanket, heavy clothes, or much food.
My heaviest pack was a week-long solo early spring hike in Arkansas, 170 miles, 65lbs. The heaviest single category was food (11lbs). But I also carried a two-man tent, heavy clothes, extra wool blanket, extra fuel, etc. I was thankful for all of it because of the cold, sleet, and rain that I encountered. Only made 4 miles the first day with a pack like that, but by the end I was averaging 17 miles/day.
A big hint, eat the heavy food first.

And don't skip any of the Ten Essentials!
By watching what people pack, a lot of weight is often taken by optional, recreational, educational, or leisure items. Candy, guide books, electronics, fresh foods, musical instruments, journal books, duplicate gear for comparison testing, etc.
A 35mm SLR camera and 300mm zoom lens are my 'luxury' item that I refuse to sacrafice.
-Bob