I have a 7x57 1902 #5 RB and have had excellent results with handloads using the 175 RN Hornady bullets....unfortunately,
the bullet is no longer sold. Using nexk sizing, case life is reasonable 3 or 4 loadings is not a problem. Chamber is oversized
because the action design has essentially zero camming capability. The "different version" is just baloney. The ammo
is the same, the chamber is oversized because it had to chamber dirty ammo and a dirty chamber with almost zero
ability to force it in. Much like the Brit SMLE chambers, which are ridiculously oversized in many examples, but
since they never even contemplated reusing brass, nobody cared even a tiny bit. They loaded, they went bang,
the brass hit the ground. All was good. Then some crazy guy wanted to reload the brass.........
The load my rifle shoots best is 36 gr of 4064 under the 175 Hornady. The bore is extremely worn, but I have still
gotten 2.5" 5 shot groups at 50 yds. with a 150 LBT design cast. The diam used was .285, and almost certainly too small
for best results. The Jbullet 175s could produce 1-1.5" groups at 100 yds, but my eyes will not permit me to
duplicate that, I assume, but have not actually tried it recently.
Bill