I've had both, neither is a bad choice in a rifle built properly,...but thats the key, "built properly". They both need to weigh 10.5 lbs or more, on actions that accommodate the length of the 505, and an appropriate action for the stubby 550J. I stuck with the 500j on a short fat Granite Mountain actioned rifle with a 22" barrel, I've killed multiple buffalo and a bunch of other stuff with it. Either caliber hits like a lightening bolt from the sky. Shooting either is not for the faint of heart. I use an evo shield shirt with a super thin protective plate in the shoulder to practice so that eliminates the shoulder punch but it still torques your entire upper body during recoil, so if you have a bad back or neck I wouldn't venture into this realm, you will be above 90 ft lbs of recoil, to compare, a stoutly loaded 416 rigby that weight 10.5 lbs generates about 58 ft lbs. The recoil of these .5" hammers is next level. The one other thing I would mention is I have hand loaded for both, and for some reason the Jeffery seemed easier to load and keep ammo concentric, the brass lasted for at least 8-10 firings with both bertram and norma and the primer pockets were still firm fit, and the neck tension was always uniform.
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