Nothing wrong with Hornady products, time for someone else to have a Snickers. I like these posts - new shooter, new rifle and scope, and new to reloading. Its hard to know where to begin...
The suggestion to try some factory ammo has merit. Making sure all the various fasteners are tight has merit. Shooting off sandbags has merit. Letting the barrel cool between shots has merit. Letting someone else shoot the gun has merit. This will let you know if the gun/scope/operator is the problem. Having jumped through these hoops, one can address the reloading aspect.
1) Rifles tend to tune to a particular bullet weight, try a few different ones. This has little to do with barrel twist, rather its barrel harmonics. A good bullet tends to show promise "right out of the gate".
2) Many rifles prefer flat base bullets over boat tails ( even match grade boat tails)
3) Pick a powder that is speed appropriate. (3031 is too fast for 100 gr bullets, as per Ganderites post)
4) Strive to achieve consistency from round to round, and keep detailed notes.
Try to have fun at this, it often takes some patience to sort out a new gun.
Uh, I never said I was a new shooter.
I am new to "grouping" / accuracy testing.
Definitely new to reloading
According to Google there may be something wrong with those hornady spire points in some guns. This is why I was stressing about barrel twist and bullet weight. What you are saying about barrel harmonics is so far beyond my knowledge level. On a few forums now through my search guys are saying they get far better accuracy out of lighter 85-95gr bullet in a 1:10 barrel twist, which others have had similar experiences to (it probably doesn't explain why my garbage groups at sub 100yds exist, but it is something I will pursue)
I have shot far better groups, unsupported with my 4570.
That is why I am here (and why I figured I'd try IMR3031)
I absolutely found a listed load for it, so I figured, heck if it's so good in my guide gun, why not my new bolt.
Thank you for the advice and I am absolutely having fun. Mostly I just had a heart attack thinking maybe I bought 200 projectiles that may not like my barrel, it was all they had at the time though.
My last batch is done, I laddered from in 0.5gr intervals and zeroed my scale to the casing for each powder charge, if it didn't come out exactly like the others I dumped and restarted, I also made doubles of some charges with the bullet seated right on the lands to see if that effects the groups.