Using the same gun with a factory barrel, mine likes 77gr DTAC ammo the best.
Federal Gold Medal Match would be a very good one to try for groups as well. I like that you can get it anytime anywhere and it's pretty consistent even between batches for me.
For factory loads, those would be my best recs. Prime wasn't bad but my gun preferred the two above.
Try an assortment of 77gr SMK or 75gr match loads (the Pvri isn't a match load); some of the 69gr group well, but I've had the best results past 500 using the 77s.
These will fit in the factory magazine.
If you're new to rifle shooting:
1. let your barrel/throat cool between strings of fire- shooting non stop is fun but will kill your barrel in short order
2. start with cheap 55gr bulk ammo (Wolf Gold or American Eagle... not Wolf/Tula/Bear crap) and work on the basics; when you can group consistently, THEN go to the more expensive 77gr ammo - difference of 3-4x in cost
3. if they still have a Snipershide online school- do that before you put a lot of rounds downrange, will answer a lot of ?s for you
4. don't skimp on the picatinny rail for your gun- get a 20MOA rail NOT 0 MOA
5. whichever scope you get, get a quality one- doesn't have to be expensive, but get one that is highly rec on the Hide
6. whichever scope you get, get quality rings. Seekins or Vortex branded Seekins are best for the $$$ IMO; used rings are almost always good if they are factory looking because they are protected by the much more delicate scope and don't really move much
7. Given that you don't have a cheek riser, a $7 ACE bandage (black) can be used to soften/cushion/build up your cheekrest to the height you desire.
8. If you plan on doing this a LONG time, start looking at suppressors. Shooting will rob you of your hearing over the years. A good suppressor will last you 20 years easy. Thunderbeast Ultra in .30 cal (for bolt guns ONLY - best for bolt) or Silencerco Omega in .30 cal (great for bolt but can be used on a semi auto as well). The paperwork takes a while so consider starting that timer soon.
*I'm not current on the latest suppressors, these are just 2 that I have and recommend
9. Get the standard Harris that everyone has with the swivel with a locking knob or the Atlas PSR for bipod. I have both, both work well- I prefer the PSR.
10. use a rear bag
11. Have fun. Emphasize the shooting and skillset. The equipment shouldn't be the focus.
12. Don't run out and get a new gun/caliber. You've got a great gun. Have fun with it and learn, enjoy the sport.