Range Report 224 predator, 6.5 twist, 88 gr ELD-M, 2800 fps

[hlee]

So, I had my new 224 predator out at the range this week. I thought I had found a good node at 27.8 grains of CFE223, 10 thou off the lands, but a few pierced primers (CCI 400) have me taking these cartridges back to components and starting again. Anyway, I have had a few (maybe 4 or 5) out of about 100 rounds fired that didn't make it to the 100 yard target. Not sure why, but I think I finally have a clue...

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Is a 6.5 twist at 2800 fps too fast for the 88 gr ELDM? Obviously, with the pierced primers I'll be dropping the charge weight, but this has me rethinking the bullet choice- which is a shame as they are the cost leader for match grade components. And, if I can't keep the speed up, this rifle is no better than the 6.5 grendel that I have that is the proverbial laser.

This was shot with a muzzle brake on the rifle and there doesn't appear to be any strikes on that. But, I've taken it off and will be shooting the rifle with just a thread protector until I get this squared away. Not that it recoils much anyway.

Thoughts? Ideas? Thanks.

 

[spife7980]

You at least need to rethink your primer selection. The 400 is a low pressure primer, from cci the 450 is what you’re wanting to use.

2800*720/6.5=310k rpm, that a lot.

 

[Mordamer]

6.5 is too fast of twist. Even 7.5 twist barrel will fully stabilize the 88 ELD. I have shot them in a 1:8 twist barrel at about 5000 DA and 2,900 FPS and they were stable out to 800 yards and probably farther.

When you get into the really heavy .224 bullets you have to walk a fine line between spinning them apart and stabilizing them. Even a 7 twist barrel will spin a lot of .224 projectiles apart.