By the 1930's tracers and armor piercing bullets became all the rage and machineguns too, so longer bullets loaded to higher pressures was the norm.

That resulted in the elongated 1 1/4" leade on the late c chambered rifles so they could digest the new ammo and not blow up. Only a select few were converted because it was only specially trained riflemen that had this ammo, the grunts had standard fmj and that was it.

I found some bullets in a case of 8x58RD tidbits.

Top: 173grains Tracer
2: 196grains standard fmj
3: 230grains RN fmj (old style)
Bottom: 124grains fmj short range/reduced load

---