I have 2 7mm LRMs I load for. I never could get the 175 ABLR to shoot to my satisfaction. Not saying everyone will have the same experience but my experience seems to mirror what you are seeing. My LRMs love the 180 Berger VLDs and the Berger 195 EOLs. The ELDMs also shot very good in them as well. I primarily shoot H1000, IMR7977, and IMR8133 in these 2 rifles. So, my advice is try a different bullet. Of course check all the typical stuff, stock fit to barrel, scope mounts, torque on actions screws etc., also have another trusted shooter try the rifle with a load of known performance. Just some things that should eliminate most gotchas.
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ill ad onto this. 1:8 twist. Go 180 or even the heavier Berger. Had good success with rl 26 with 180 gr and better bullets
h4831Sc in 160-175 gr been a good load
finally. My experience has been some guns are shooters and few aren't.