Take a look at this thread.

Regarding scoping the rifle for aging eyes, if you are plan on pulling the safety on the Rossi, then think about just installing a Peep sight in place instead.



https://store.stevesgunz.com/index.php?main_page=product_info&cPath=2_16&products_id=10&zenid=1lr87lrt3v42m01j2rvi2le9t4

As for the skinner type peep aperture, two mods from the start are almost a must.  The peep aperture is bored the same ID all the way through, so really helps to step channel the end of the bore back to only leave about .004" of smaller aperture wall so you don't get glare from the longer channel when looking through it.  The second mod is to put a O ring on the threads against the Eyelet height adjusting bolt so the aperture stays in place without having to over crank it down.

With the location of the peep sight that will replace the safety (same location as my express Skinners on the marlins), will find that the .070" peep is about ideal.  
The .040 would be better off the bench, but it just too tight for real hunting type/ off hand work isntead.
Note, if you deep in the swaps where the shooting will be close up and personal with the game running and need the greater side feild of veiw through the aputure, just remove the peep aperture from the base and run the much larger ring base opening itself.  Trust me, even with something like a dear at full run, you have more than enough view through the large base opening for the needed lead, plus some as well

As for the threading on the aperture base, it's 40 pitch, so each half turn of the housing will move the POI about 2" @100 on a 20" barrel.
Note, the aperture can be threaded into both sides of the base.

Here is photo's of the O ring that I install on them, and the way that I step the front channel of the aperture in the lathe to prevent deeper channel sight through glare from the long ID side wall of the aperture.
Note, don't remember the size, since when I hit up Bell plumbing supply, I buy a handful of thir smaller O rings to have around the shop.  Hence the tiny ones I use for the air brushes, and these med tiny ones I use for this and grip screws for the para pistols.





As for loads, still like my 1180fps 270gr med load (the 1780fps 270gr is a shoulder thumper out of a 6lb gun, that was no joy doing 5 shot each ladder loads a few weeks back with a couple different powders off the bench), but the 270gr med loads are still a hand full with even this med load.  

Hence they don't thump you that hard that you can't shoot them a lot per outing, but your not going to speed cycle the gun and stay on plate in say CB shooting isntead.  So on that note, being sent a few of the lee 200gr bullets casted up, and if I can get them to crimp as long as my 270's in the lower crimp channel, may become my new plinking load isntead.  As stated with the 270gr, with it crimped in the lower channel, ends up with a .003" jump to lands that will cycle through the rigs; and can get these 200gr's to do the same, may be the fun to be had by all light rabbit wacker load instead.
Note, still think that the 44 is way over kill for knocking squirrels out of a tree, short of just blowing the branch limb off the tree that the squirrels is on, then catching him as he falls to earth to tenderizer him instead.