@nate45 and 4runnerman
I would say a service rifle in NRA high-power is better designed to mitigate heat than a sporter-barrel hunting rifle. In High Power (just one form of rifle competition) you usually just shoot one rapid fire string at a time right?
Also, no one adressed the fact that the air temp. and temp. of the barrel will change POI.
I live in Phoenix, AZ and I can attest that if you shoot 10 rounds in a row with a sporter rifle (in a short period of time) the POI will shift from the barrel heat. Maybe if you do your shooting in 30 degree temps things are different.