First, DNR had absolutely nothing to do in promulgating this rule. In fact, they fought it tooth and nail for five years until it was obvious from passing unanimously they had no choice.
The only reason for how it was written was to mirror what DNR allowed in handgun but in rifle configuration. If anything else was added, DNR would have technical basis to deny this rule. The key position we had was we were only asking for what was already allowed but in rifle configuration. Even then, it took 5 years to get it to NRC. The original language specified pistol up to 1.8" but NRC requested "pistol" be removed for easier enforcement by CO's which was agreed upon.
Plenty of discussion to include other cartridges but it was recognized the proposal would have never gotten passed. DNR proved time and time they had zero interest in increasing hunters means of taking game.
It is frustrating to realize how political DNR was in this process versus working with to establish a rule that would benefit hunters.
FYI - the reasons for this rule was hunter recruitment and hunter sustainability to allow cartridges like the .44Mag, .357Mag etc to increase interest for youth, women, elder hunters and even those who were recoil sensitive. Cartridges were developed afterwards like the .450BM and 350Legend as result.
There is no logical reason why 45/70 shouldn't be added now except for DNR zero desire to do so.
Before anyone tries to refute this posting, I authored this rule in partnership with Matt Lori of 59th District. I have complete documentation of everything. In fact, I have sent copies to other state groups to start similar rule.