I'm in the Hornady fan club so most of my shooting is with them. I started my girls with SST's and had great success. One shoots a Marlin XS7 and the other is a Weatherby Vanguard Camilla. Both have 20" barrels and a 9.5" twist. SST's sling lead everywhere and I wanted to start eating the hearts, and now maybe save the organs for the dogs to eat. So I switched to Hornady GMX(all copper). Both guns shot them great. Then Hornady switched from GMX to CX. Still good. Then I decided I wanted a 7mm08. Bought a Tikka T3x Hunter. It has a 22.5" barrel and hates the CX bullet. Bought a bunch of different bullets to try out. It shoots ELD-X, Federal Fusion and Winchesters about the same. I went with the ELD-X because I'm a fan boy for Hornady. Fusions are bonded bullets and ELD-X's are cup and core. Nosler doesn't make partitions anymore? How come you can't get them? Any cup and core bullet should shoot good out of that gun. Remington just came out with a green "tipped" core lock. Maybe try that one.
Fun story time:
Back in my early 20s when I first got into hand loading I (stupidly) pushed the limits quite a bit with over-pressure. "Eh, there's probably a 10% safety limit built into these guidelines."
I was loading varmint rounds for a trip out to New Mexico. I took a few different combinations to try for my 18" .223 Varmint AR I built; 35gr Barnes varmint grenades, 35gr Nosler Ballistic (Orange) tips, and 40gr Hornady V-max (Red tip). I was shooting them while braced across the hood of my Dad's Dodge Durango out in the middle of the desert. When they hit a prairie dog or a jack rabbit, they legitimately turned them into pink mist. It was glorious. However, sometimes it was like the bullet never hit anything. I couldn't figure out why for a few days.
One evening, the sun hit the hood of that red Durango just right and I saw this fine powder scattered across it. Wiped it up and it was orange plastic dust. Long story, long, those bullets were traveling and spinning so fast, it was ripping the jacket off when they left the barrel and were spinning themselves apart. 😆. Whoops.
These same rounds would flatten the roll marks and primers on the back of the casing and occasionally squirt the primer out the back into the trigger assembly of my AR. I'd then have to take it apart to shake the primer out. I decided that was enough stupidity and put those away for the rest of the trip in favor of off-the-shelf ammo.
When I got home I pulled every one of those apart to reclaim the components but not before I shot a few across a chronograph. Average was >4200fps. Waaaaaay too fast for a .223.
Anyways, don't be dumb like me.
That being said, I'd love to someday build a wildcat capable of 5,280fps. I bet I could get close with a .243AI, .220 Swift or one of these newer 6mm variants. 1. Just to say it shoots 1 mile per second and 2. I bet it would be fun to watch what it does to a coyote.