Joe F,
If this is a new rifle? don't forget to shoot, clean, shoot, clean. I had a Sendero in .300WM years ago (1st gen w/solid blued barrel) that took quiet a few shots to break in the barrel, probably close to 150 rds. I did a lot of cleaning in between shots, almost to the point of exasperation. IIRC it came around, somewhat, accuracy got down to about .5" with bullets/powder it liked. I wanted to shoot 180gn + and it really loved the 165gn range. I keep it a little while and traded it off for another Remington, a 700 VS (older version) in .243 Win which was delightfully accurate.
I have long since left the factory Remington's. Tooo much worrying with for me. Shooting a Savage 112 BVSS now in .300Wm that recently shot a 5" groups at 1200yds with 212gn ELD-X's.
(I do have a Remington 700 based Kirby Allen rig in .270 Allen Mag that is unbelievable! 14.5 MOA at 1000yds with 169.5 Wildcats at 3450fps.)
Good luck with your Sendero. Hope it comes around. Keep us up to speed. johnnyK.