Split groups

[wsftr]

sounds like you have changed everything.
What about the rest its shooting off?
I remember someone on this forum chasing a problem and they swapped everything and it only occurred on the heavier recoiling rifle. Long story short the heavy recoil caused an issue with a screw not correctly torqued or something like that (I can't recall exact details now). I think the difference was between a 6.5 and a 7mm so you would expect the 6.5 to still have had issues but it was fine just the 7mm had the issue.
Maybe there is something in your gear (rest/rear bag) and setup that is an issue for the SAUM but doesn't show in the .308 for example.

[Josh Cox]

Like this (230 ATIPS):
https://shooting.hexsystems.com.au/shooting/292880

[AlanF]

Like this (230 ATIPS):
https://shooting.hexsystems.com.au/shooting/292880

A very good example. That's dated January 2020, so did you get it figured out?

[Josh Cox]

That was with a borrowed super fast twist barrel that I did not want to put too many shots through, I have another barrel the same as this about to be chambered and I intend on having another swipe at the 230 ATIPs in FTR.

[AlanF]

That was with a borrowed super fast twist barrel that I did not want to put too many shots through, I have another barrel the same as this about to be chambered and I intend on having another swipe at the 230 ATIPs in FTR.

If everything else about the rifle is unchanged and the new barrel behaves, then that points the finger at the borrowed barrel I guess.

[KHGS]

That was with a borrowed super fast twist barrel that I did not want to put too many shots through, I have another barrel the same as this about to be chambered and I intend on having another swipe at the 230 ATIPs in FTR.

If everything else about the rifle is unchanged and the new barrel behaves, then that points the finger at the borrowed barrel I guess.

Or the bullets!! Split groups usually indicate an unhappy load combination.......if all else is correct.
Keith H.