Partsman,
On a prairie dog shoot hosted by Kimber many years ago, a bunch of writers were mostly shooting walnut-stocked .22-250s with fairly light barrels--really more suited to coyote hunting than PDs in afternoon temperatures around 100 degrees. My shooting partner got his so hot the forend started burning. At first we smelled it, then saw smoke rising around the barrel. We finally stuck the barrel and forend in the melted icewater of a big cooler to put it out. Have no idea whether the barrel itself was truly toasted, but it got hot enough to start melting the cores in the thin-jacketed bullets of the factory loads we were using--which also did not do anything for accuracy.
There were a few .223s as well, and I brought along my own, an older Kimber, so switched it now and then for the .22-250 I was also shooting. Even so I fired about 600 rounds of .22-250 ammo from the first morning into the next morning (I kept track because we got to bring the brass home, and I dropped all the empties into a small duffel bag), when I discovered that a relatively light 22-250 started feeling more like a .375 H&H each time it went off. As a result I'd started flinching slightly, so after that switched to the .223 for the rest of the shoot, which helped a lot.
