I'm not understanding taking the 50-yard mark away as well. Assuming we're all shooting at the same type of target (wood frame, paper target) how does 50-yards produce more ricochet? When they say ricochet, are they worried about the shooters or the illegal hikers? It seems like if they took away the 50-yard mark, it's the shooters.
Is there some way we can be proactive on this, someone we can write, etc?
There's some logic behind it actually.
Particularly lighter bullets will deflect more, and a same-angle deflection further from the backstop will result in greater overall deflection. Simple trig.
A 10 degree vertical deflection at 50 meters, would rise 8 meters, the same 10 degrees at 100 meters would be 17 meters.
As the deflection angle and distance increases so of course will the absolute deflection. Essentially with enough deflection (ignoring the loss of energy in the ricochet), the closer to the shooting bench the deflection, the greater the risk of you overcoming your backstop.
That said, I'm skeptical the 50m is based on any real analysis; I suspect it's just a quick 'do something' measure. I could do a detailed analysis if anyone's interested.
(Calculations ignoring gravity/air resistance, assuming perfectly flat trajectory).