OK, so I've checked with guys on the 6.5 Creedmoor Forum, some of whom compete with the ELD-M rounds, and they report NO bullet breakup whatsoever.
That's been my experience too, but I've only shot hundreds of ELD-M rounds, not thousands like many on the 6.5 Creedmoor Forum. And some of these guys are also pushing them up into 3,000 fps in the really hot 6.5 PRC hunting cartridge, again with no problems.
Howsomever, if shot through an over-coppered barrel it is possible many of the thin jacketed bullets of any brand may "break up" in flight from jacket disruption in the barrel.
VLD Pilot, you may have been given the wrong info but I'd be interested if you could post or PM me with the sites that have this "blasphemous" information. Yes, I'd agree from my own use, that Berger Hybrid bullets are a tad more accurate than ELD-M bullets. I don't shoot Berger Match bullets B/C they load with a COAL that's too long for my magazines and I need magazines in my RPR for competition.
My Ruger 6.5 CM rifles (RPR and RAP) have 5R rifling which deforms bullet jackets less than standard 6 land square cut rifling and also provides a better gas seal with its angled land sides.
So I'd say ELD-M and/or ELD-X jacket breakup is another internet rumor based on one or two extreme situations. Jus' saying'...
Eric B.