Hello Mr. 16 gauge,
I apologize ahead of time for the length of this rant.
Good questions, thanks for posting them.
One of the main topics I never stop jabbering about and asking questions about is the topic of hunting rifles and everything related to same.
The following stuff applies only to people who have relatively adequate eyesight, not to people with particularly bad vision.
Poor eyesight pretty much requires a scope for precise shooting.
The only DG I have shot is the buffalo shown in my avatar here but, it is important to note that I thoroughly discussed with my PH my intention, to use an open sighted rifle for buffalo.
He assured me that since we had hunted together on numerous PG in the past, he was fine with that plan.
I used a .450 No2 NE double, with wide "V" rear blade and over-sized German silver front bead.
All went very well, except not from the buffalo's point of view.
Be that as it may, the PHs I've had the pleasure of discussing rifles with over the years, have been pretty much unanimous on this topic of rifle sights.
PH's Back-up Rifles for DG:
They all seemed to have either the .458 Lott or .458 SA 3" Express, bolt actions, either Brno 602 or CZ 550 models, modified to their preferences.
These modifications always included a single/fixed (can't fold it down) steel blade rear sight, filed into a very wide and shallow "V", with a thin white or silver color vertical stripe, leading up to the bottom center of the "V".
The front sight was always a large white bead, such as porcelain or warthog ivory (doesn't turn yellow with age).
When I say wide and shallow, the ones I have seen in Africa were filed to barely a "V" at all.
At first glance, they look so shallow that they almost appear to be flat across the top.
Also, I have fired a couple of these "express sighted" .458s as well, at paper targets.
Compared to a scope or even to a peep sight, they are not as precise for longer shots.
But, out to a bit beyond 100 yds, the "express sight" is accurate enough for what they were intended.
PH's preference for client's DG sights/rifles:
Again, the several PH's I have asked about it, have been pretty much unanimous on this as well.
They like to see a client show up with a not too glitzy bolt action or even a single shot rifle is fine but, definitely a low powered scope in sturdy rings is the best sighting choice for most DG hunting.
By low powered scope, I mean either a fixed power (non-variable) of somewhere around 3x or 4x, or likewise a low powered variable, such as 1 to 4x, or 2 to 7x and similar ones.
Detachable rings are not needed, unless you either insist on using one of these giant front lens scopes or, in the event you break your scope.
If you muff your first shot and the PH is OK with you going on the follow-up, a clownishly large scope can get in the way of your mission and of course, a broken scope is useless.
So, with detachable rings, you can pop the scope off and proceed into the thick stuff after your unhappy beast.
I have not discussed leopard much with PHs because I am hyper active and could never sit still long enough in a leopard blind so, it is pointless for me personally.
However, I will guess that a large front lens might be good to gather light at dawn or dusk on baited leopard - just a guess though.
Evidently, elephant hunting is an either/or sighting choice.
In other words, a scope is not needed but a low powered one is perfectly acceptable, if you prefer scopes.
Last but not least, they tell me that for DG, a scope is otherwise usually preferable, not because of long shots (PH's like to put clients in close to DG for that all-important first shot).
But, DG scopes are for being able to sort out any errant stick between you and your animal, that are not visible to the unassisted eye.
Detachable rings and mounts:
Again, these evidently are not essential but, personally I like them for all of my bolt actions, DG calibers and non DG calibers both.
Claw mounts are in a league of their own and nothing even comes close to them (nothing comes close to their super high price either).
www.champlinarms.com is the best place to have them installed in my opinion.
As far as affordable detachable rings go, have a look at:
www.alaskaarmsllc.com
They are the lever type and very well made.
Also, I like the older style Talley brand lever rings and bases (not the newer ones that fit Weaver pattern rails).
Get yourself a sturdy bolt action, with express sights or auxiliary peep sight and install a quality, low powered scope on it, low down close to the bore and zero both sighting arrangements well from sand bags.
Then forget about the sand bags.
Now, primarily standing and shooting from sticks but also from various other field positions, simply practice, practice, practice ... then practice some more.
Cheers,
Velo Dog.