Had a contrary 243 that refused to comply will the recommended powders. On a whim, I took some 4320 off the shelf and tried it with 100 gr Nosler Solid Bases. Bingo: consistentl 3/4” or better groups.
And the Nosler discontinued the bullet...
Funny you had that experience.
Years ago while doing some load development for on of my .280s, I decided to burn some 4320 for fouling shots since I had about a sixth of a pound someone had given me. I don't recall which bullet I was working with but I chose an arbitrary charge in the middle of the recommended range. I think velocity was supposed to have been about 2500 fps, which didn't matter at all for my purposes. I'll be damned if the load didn't print three in about one fourth of an inch. Quarter inch groups don't normally irritate me, but it did that day.
