I’ve never had an issue shooting the 40 grain BTs through 8 twist 22-250’s or 223’s. I’ll take more RPMs everyday of the week. If they Bullets won’t stand up to the RPMs I probably didn’t wanna use them anyhow.
Never tried any Hornady 40’s but as stated, the 52 ELD is a super Bullet in 8 and 14 twist 22-250’s.
I have a 6.5 twist 224 Predator (22 Grendel/22 PPC AFI) that has only been fed 75 ELDs and 88 ELDs so far. I do admit I'm a little curious as to whether the 40 vmax would hold together.
As to the original question, I'd look for some 53 vmax, 52 ELDs, or 50 vmax. Shooting is better than not shooting and I guess if you were desperate you just scrounge up whatever, but those would be my first three substitutes. Actually, come to think of it, I like those better than the 55's.
