The smallest groups I have ever fired with a factory rifle and factory ammo have been in the 1’s, using a Savage 12 BVSS and Remington UMC 50 grn JHP’s. About as cheap as it gets without going steel, I used to pick them up for a marked 34¢/round, but actual price of 17¢/rnd because Gander Mountain was getting replacement SKU’s from Remington - 40 round boxes at the price of 20rnd boxes - because Rem wasn’t delivering. I bought tens of thousands of them through Gander over a handful of years, literally a pallet load once, more than their GM was ordering for their own shelves. Always bang, and almost always small shooting. They’d hold around 1/2” in my post-ish-ban (ban upper on a preban buttstock) Hbar M4gery 1:9” Bushmaster, and shot ridiculously small in my wife’s Savage 12 1:9”. Just have to figure out what your barrels like - custom barrels are easy, factory barrels tend to be more finicky about what they like. One load might shoot better than another, even one lot might shoot better than another, seemingly without rhyme or reason - that’s part of why folks are willing to pay for custom barrels.
I’ve also done very well in a 1:9” with the 73 ELDm load out to 800.