The Thompson vernier sight is almost impossible to find. The guys I have talked to said they were not rugged enough for hunting.
The Thompson peep is rugged enough for hunting but it does not have the bells and whistles that the 57 has.
The 57 sml can be adjusted in the field. You can have per set ranges out to how ever many yards you want. SO if you have a 100 yard shot set it to 100. If the shot is 135 yards, you set the sight between 125 and 150. You can't do that with the Thompson sight.
The sight can be taken off when you not hunting reducing the potential for damage. You can instantly slide it back on with a simple push button and it stays sighted in. I carry mine in my pocket when I am in an area I don't think will have game. I also keep it in my pocket when in the truck or ATV.
The 57 sml is a 1/4" click adjustment at 100 yards. The Thompson is not.
In my opinion the 57 sml is the better of the three. But some guys think they are not rugged enough too. I have used them for many years now. I have used mine to take deer and antelope. If other guys don't think they are rugged enough I would not let them borrow a gun of mine.
On the potential to get out to 200 yards. The front sight will need to be changed. At 200 yards the OEM front sight will cover a barn. I use the 17 AML but that will still not be enough. The sight inserts should be changed to a Lee Shavers BPCR long range insert. That set up will get you to and past 300 yards.
Lastly, it is not enough to just hit at 200 yards. The load has to have enough power to get the job done. Large conicals rule at this game. The adjustable 57 SML will adjust so you don't have a big hold over or hold under. You just use a range finder get the yardage, set the sight and hold dead on. Ron
