matchup, and really not so much a HP thing. I have 3 or 4 very accurate HP's which actually outshoot my RN or FN bullets by Just a tad. I'm sure you knew that but i'm just saying HP's are accurate and maybe just your gun doesn't like that particular bullet.
Also as far as expansion goes, 1 thing IMO is your velocity is pretty slow for TOTAL expansion and you are also shooting it into wooden material and the HP gets instantly clogged. WOOD IS NOT A GOOD TEST MEDIUM but it does make great target backers..lol.
Have you slugged your LW barrel? There are reports of guys with LW barrels that have bores that vary buy a lot from 25 cal barrel to 25 cal barrel. Some guys are reporting .253 and .251...etc..etc. It over on the TAG forum.
And again, love that gun. The stock and the looks are awesome.