.223 with 6" twist shooting the 88 ELD at 2600 would be a great learning tool.
Does it need a full 6 twist? 90s stabilized in a 20 inch tube with 6.5 twists. That said maybe I'm lucky, I have a bolt gun tube maybe a hart, but a good name in 6 twist and had no clue what to use it for. Maybe you answered that itch....