Steyer
I shoot one of the Prarie gun works 50's, It's absolutely fantastic and one of the most accurate rifles I own with the right load. My buddy two summers ago got tired of asking can I try it and decided to buy his own 50 cal. He bought the Steyer HS 50 I can email you a pic of the two of them together if you like.
The Steyer has an easier trigger with some take up, mine is heavier with almost none, The Steyer has a bigger more effecient Muzzel brake mine is smaller and doesn't blow a blast of air/dust/ debris up your nose each time.
My muzzle brake send the blast more sideways while the Steyer sends it back into your face, my buddy wears goggles while shooting not just glasses (looks kinda silly actually)
With mine i've put 6 rounds in the same hole from 100M best I could do with Johns is 3-5 rds inside a 2.5 " circle. For an extra 1000-1500 John could have had one like mine.
Johns does break down nicely and has a good hard case for his while mine only has the stock unscrew leaving it looking like the worlds nastiest pistol and then goes in a drag bag.
If i had to buy another 50 cal i'd buy another Prarie gun works,,,,, actually John says that too.
Mike.