Fire away, and record the temp every 15 seconds for 5 minutes, then show us a graph. I can't wait to see it.Only issue is the steel barrel can take more powder than the carbon. Not much. .5 grains. But I could just drop it down a grain and let (4) rip with same time between shots. I would put money on the steel one being cooler. I have a Fluke temp gun I can shoot down there. Or get a Fluke temp probe for my digital meter.
I have a CF barrel on a 300 WM rifle, and a heavy steel barrel on a 300 Wby Mag.
Of course, the loads are different, so I hesitate to do the experiment, figuring everyone would dismiss the comparability. Of course, the results with the steel barrel are going to vary with the countour, and with the CF barrel, they apparently will vary with the manufacturing technique. But some comparison will be interesting.
Anyone else have suggestions for design of the experiment?