Training objectives: skills, confidence, realism...
This is an interesting discussion because two concepts emerge: something like 6" @ 100 yards, and something like 2" @ 100 yards.
First let me observe that 2" @ 100 yards is 2 MOA. Therefore, theoretically, to hit reliably 4" at 200 yards, or 6" at 300 yards, requires the same shooting skills as hitting 2" at 100 yards. There is therefore a strong logic for the 2" plate at 100 yards.
However, although I do use 6" at 300 yards, which is 2 MOA, when I invite friends to learn to shoot off the sticks I do not use 2" at 100 yards. I still use 6" at 100 yards, which is 6 MOA, then 200 yards, which is 3 MOA. Why?
The reason for this is that the other objective of training, besides developing skills, is to develop self confidence and trust in one's shooting.
Skills and confidence...
As
Bob Nelson 35Whelen stated: "
You will be amazed how hard it is to consistently hit a 2 or 3" inch target off sticks and in field positions (at 100 yards)
with a 4 power scope."
It was not all that long ago that shooting 1 MOA
from the bench was the gold standard, often unattained, for hunting rifles and hunters. Countless piles of ammo were shot (and still are) to find which load would do this in which barrel, and countless dollars were spent (and still are) on gunsmithing accurizing jobs to go down from 2 MOA
from the bench.
Shooting 2 MOA
standing off the sticks is a lot more difficult than shooting 2 or 1 MOA seating from the bench, and it is my belief that setting immediately the goal of shooting 2 MOA standing off the sticks, especially with centerfire rifles of appropriate PG caliber (say .25 and up) is counter productive for shooters
new to the sticks. They will likely almost never hit and will get discouraged...
Yes, a 6" plate at 100 yards will encourage less precise rifle control skills, but it will also encourage confidence-building in the beginner. As confidence and skills grow, that same 6" plate that represents 6 MOA at 100 yards, will represent 3" MOA at 200 yards, and in time 2" MOA at 300 yards.
As to realism, ANY hit in a 6" vital area will reliably kill any PG bigger than the Tiny Ten (and any DG - except for elephant, hippo, croc brain shots, but these shots are taken typically at close range).
Keep in mind that hunting shots are not judged with a scoring gauge, and that staying within 6" AT THE DISTANCE THE ANIMAL IS SHOT already provides a safety margin that grows as the animal size grows, because, actually, the vital areas of commonly hunted game are larger than 6":
--- Pronghorn / small deer / small African antelopes: ~8"
--- Medium size deer / medium African antelope: ~10"
--- Large deer / North American wild sheep / mountain goat: ~12"
--- Elk / large African antelope: ~14"
--- Moose / Eland: ~16"
I am certainly NOT advocating for "spray and pray", but I am advocating for realism. Any hunter who keeps his shots consistently, reliably, predictably in 6" AT THE DISTANCE THE ANIMAL IS SHOT will kill cleanly and ethically, and
it is absolutely great for someone new to the sticks to hold 6" at 150 yards, which is a very common shooting distance in many hunting scenario in Africa. Believe you me, any PH that I know would be ecstatic if most clients showing up in Africa could do that; it is the exception rather than the rule...
Additionally, there is a lot more real-world hunting value in shooting relatively fast in 6" at 150 yards rather than shooting slow in 3", never mind 2".
When the range opens to 200 or 300 yards in open plains or hills, there is generally more time to take the shot, and having practiced, and been humbled, on 6" will yield great confidence and success, as straying a bit wider than 6" due to excitement, fatigue, wind, uncertain position, rush, etc. will still produce great killing shots on medium and larger PG.
I would recommend to start building the skills and confidence on 6" at 100 yards, because it represents the reality of hunting, and as skills and confidence grow, there is a lot more value in pushing the 6" plate to 200 and 300 yards than there is in reducing the size of the plate to 2" at 100 yards.
Just my $0.02, and to each their own