Almost always its related to the projectile. I"ve never had a cheap FMJ or maybe even an FMJ for that matter, that could hold consistent MOA.
Whatever ammo it came in, if you made Mexican match out of it with a top line bullet the accuracy almost always settled pretty well.
No experience with todays cheap but if you bought cheap reloads with a decent flat base HP bullet in it I don't recall any brand that would not hold MOA in a good upper
I've only found 2. About 20 years ago I had a very good lot of S&B that would hold MOA, and the early Norma TAC in the black boxes would hold MOA in some, but not all, of my guns.
I recall the Norma did in some folks. By that time I'd learned I could buy cheap accurate bullets in bulk and could load usually better ammo for the same as buying cheap FMJ. Maybe less depending.
There was a lot of something in 223 once. Or 5.56 I"m sure, that was close, it would tend to hold 8 or so of the shots tight enough, but never a full group of 10.
