i have delt with the 243 barrels many times, and tim is right!!!
barrel temp is the most problem in just about every 243 barrel, even the bulls.
but not as fast to throw out...
i did an experiment with an infared gun, and found barrel temps 48 degrees above ambient
at 9" past the chamber, will affect poi vs poa... with the ultras, and super's
what you can do to hurry cooldown is to insert a brass or aluminum rod ( a cleaning jag rod) into the open chambered barrel and set it aside... the rod acts like a heat sink and will quicken cooldown up to
10-15 minutes, acording to your ambient temp....
these barrels are great shooters, once you get them on zero.... cold !!!!
if you hunt, thats your most important shot anyway (1st shot).... imho i don't think these barrels were made to use as a target shooter... at least i would not do it.
good luck with them !!!!