There are actually a number of .224" heavy bullet choices that are used in F-TR and/or other disciplines at this point:
Berger 85.5 Hybrid
Hornady 88 gr ELDM
Sierra 90 gr Matchking
Berger 90 gr VLD
Sierra 95 gr Matchking
Can you shoot them too fast and over spin them to the point of disintergration in the fast twist required to stabilize?
Yes. This can be done in a .223 Rem, so it definitely can be done in a cartridge with greater case volume.
However, the key to jacket failures seems to lie in the bore diameter, and other minor contributing factors. In .223 Rem F-TR rifles with long (28"-30") 0.218" bore barrels, going with a twist rate faster than 7.0 is known to potentially be a problem for loads where the 88s/90s loads are being pushed up to around 2850 fps. Dropping the velocity down to the 2750-2775 fps range on loads in these setups seems to do the trick and mitigate jacket failure. In addition, using a shorter 0./218" bore barrel (i.e. </= 26" or so) seems to do the trick.
Alternatively, using a 0.219" bore barrel seems to alleviate most of the other contributing factors such as twist rate, barrel length, etc. With 30" barrel length and 0.219" bore, running twist rates faster than 7.0 and velocities in the 2850 fps range no longer seem to cause jacket failures the way they are sometimes known to do in a comparable 0.218" bore barrel. In other words, lots of little things can add up to become "the straw that broke the camel's back" in terms of jacket failure, but going with the 0.219" bore seems to largely alleviate the effect of the more common contributing factors.
How these factors affect .224" heavies in rifle cartridges much larger than .223 Rem is less clear, or at least, the upper limits where jacket failures might start to occur are less clear. In part, that may be because not so many shooters outside F-TR competitors are running barrels in the 30" length range. Much of the issue with the long heavy bullets is due to friction and their long bearing surfaces. Having a shorter barrel (26" or less) means a lot less friction. But it's still less clear
exactly how hard the .224" heavies can be pushed in cartridges with much larger capacity than the .223 Rem but with shorter barrels and still survive to reach the target. I would certainly try to use a 0.219" bore barrel in a .22 hotrod if possible, regardless of barrel length.
The final consideration is the thickness/toughness of the bullet jacket. Not all manufacturers are created equal. I am not aware of any F-TR shooters having jacket failure issues with Sierra's 90 or 95 SMK bullets, which seem to have very tough jackets. I have personally blown up Berger 90 VLDs and Hornady 88 ELDMs in a rifle that had a 30" 6.8-twist barrel, as have plenty of other F-TR shooters. So if jacket failure is a concern, especially at the velocities possible with some of the .22 hotrod cartridges, the tougher jackets on the Sierra bullets might be a good place to start.
