I shoot in Canada for the most part and we have ALOT of 6br and dasher shooters locally. An amazing combo and very tough to beat out to 600m UNTIL the wind comes up.
Stayed ahead of the blood bath with my 6.5 Mystic and 140gr Berger VLDs one fall match a few years back. The 6.5 was the BIG combo in its day years back. When the winds ebbed on Sunday, couldn't keep up with their X count but they lost so many points on Sat, I stayed on the podium.
By contrast, I had the pleasure of watching some amazing wind reading in a gale at 900m from 6BR/dasher shooters to shoot the only cleans at that distance. Yes, we had 284/shehanes and 300's there.
Those two shooters got the condition dialed in and handed us our..... you know.
At Raton, last Sept, I was one of 2 223's trying our luck in the desert. I dropped out of F Open due to shoulder issues and thought the 223/90 would be the ticket - paper ballistics and all.
I had done very well out to 600m but not so much at 900m but I was prepped for Raton. Oh well, a variety of trainwrecks hurt bad but that was not a problem with the combo.
What was the problem was how unforgiving it was to the switches and twirls typical of Raton. I had the pleasure of shooting with two of your countries top 308 drivers. It was quickly obvious that size did matter.
The heavier 308 bullets simply stayed on course a whole lot better. When a condition came through that hammered us all, the heavies beside me might move to a wide 10 or 9, where I would be tossed a 9 or worst.
I figured I was loosing at least 1/2 a scoring ring under the same oops.
Later that day we scored a 6mm something or other. That shooter was hot before the winds came up. He drilled that spotter so many times, we were thinking we need to grab another. He was building a 3" group on the edge of the 10/X
Then we saw a big gust come through..... Target came down and "no hit"... No way.. Look, look, look somemore.
In the 6 rings was a lonely hole. Yikes. Up went the target and the thought was "don't over correct". Well, you guessed it, 7 the other side. Not a lot of shooting happened for a long while.
The shooter finished with a variety of everything. Now I know he got lost and never figured out what the air was doing but would he have moved that much given a much heavier slug?
My experience says no.
So given the direction to real heavies in 308, smaller "more accurate" cals can come join in. if the wind blows, they will be a small boat in a big sea.
If memory serves, there were only a few rigs smaller then 7mm at the US Nationals.
At 1000yds, bigger seems to be proving they are better.... when the wind blows in crazy ways
If shooters are looking for an accurate rig with low recoil and costs, the 223 is all that they could want. No problem beating 308's at mid range and I suspect further if the wind agrees with you.
YMMV
Jerry
PS this year, I will be bringing a 308 and ALOT of lead to the US Nationals and Worlds.