So I'm back from my day shooting with a helpful Enough Gun member. He taught me quite a few things. Thank you!
I've attached my targets and labelled them as best as my memory would allow. As you can see, I start off with some great groups - as usual - which then scatter and rise. I had trouble reaching tight groupings after that and it kept drifting higher without cleaning. My buddy cleaned my barrel with a dry cloth a few times (~4 I don't remember each time on my target and may have mixed a few up) and it would usually yield some small improvement but soon need cleaning again as my shots scattered and rose. He noted that my gun was accumulating gunk unusually quickly, possibly due to a new rifling being sharper. Still, probably not as it should be and I've shot around 1,000 rounds so far.. His Anschutz was fine without so much cleaning but had a similar amount when he cleaned it once in the middle of the day.
After ~2 hours of shooting he gave me a go on his Anschutz using the same SK Rifle Match ammo we'd been using. My first 5 shots weren't great as I was not really holding the rifle tight.. just admiring the stability from his bipod and good sandbag and pulling the trigger. I felt like a surgeon but the group wasn't the best. I then let off 10 shots holding to tight and really focusing this time... OMG I was floored inside but didn't wanna jump up and down haha. 10 shots.. 16mm grouping (12mm without the outlier!). He had similar (poor) results as me using my rifle.
His conclusion was that my rifle builds up gunk pretty quick, otherwise it was probably 'within spec'. He said I'm a pretty good shot (especially considering my setup on the day) though there's still a few tips and tricks I could learn. I had no bipod or large sanbag, just the flat range rest. My rear sandbag isn't very grippy or solid either and was too low. Having said that, I've had much more stability in the past when the range had the V rests.
He can hunt pretty well and his groupings with hollow points weren't as good as with the SK Rifle Match ammo so knowing that and that he doesn't always hit rabbits in ideal condition did make me feel better. He said if my rifle can put out the first few shots ok, it should be good enough for hunting. Even the latter groupings can yield some kills. This is true. However, it makes it hard to zero properly if it is so sensitive to how clean (and maybe cold) it is. It's as if I only get 2-3 mags to zero my scope for hunting each time I goto the range.
My plan now is to read up on a few links he gave me and go back to try and zero it for some hunting ammo. I zeroed it for the CCI subsonics at the end so I'm curious how accurate it is fresh with those. I have attached the bipod now (which I should have brought in the first place). If things go ok (not great, just ok at least) I will try go hunting sometime and see how I go. If I like it, I will consider getting another rifle then. I'll also try get a new cleaning rod and cloth. When I cleaned using his tools, it was much more snug than my set.
I think that my issues come partly from being new and not having a 100% stable setup and high expectations. But I still think my rifle is a bit dodgy. It shouldn't scatter so much after 2-3 mags and then require such frequent cleaning. Maybe it's within spec but it would be borderline at best. I might send it back to WInchester when I go to for my US trip in 3 months.