If your barrel is freefloated it will make much less difference first off.
You should be fine with three shots unless you consistantly notice the third one always stringing vertical and you know it's gotten pretty damn hot already. In this case just pace yourself and keep the barrel temp the same as it is just after firing the firt shot. I usually fire 20-30 rounds and then clean it, just pacing myself at 2-4 minutes between shots if I'm working on groups. Pretty easy to keep the temp the same as the first shot just by feeling it with your hand.
I always fire a 3 shot fouling group before I start group shooting OR hunting.
I never shoot through a dry barrel, I'm not sure that's exactly what Matt meant though. I oil the bore up and run a dry patch or two through to take out the excess, but that's it. Copper fouling will be instant if the bore is completely dry. Powder residue behind the first shot will help keep fouling down from there.
Always take note if your cold barrel throws a shot out and which way it throws it too.
Your throat should last longer if you pace yourself instead of three fast shots, but how much I'm not sure. The extra high temp on the leade is not good any way you look at it.
I'm not sure what temp to shoot for, but you should be able to keep temps down to whatever the first shot heats things up to, a little more or less if you want.
What's too hot? Very subjective also, but seein's how I use my hand to test I'd say 153.295 degrees. [img]images/icons/grin.gif[/img] Sorry, couldn't resist. [img]images/icons/smile.gif[/img] Good luck though, I couldn't begin to put a number and errosion rate on it, testing would be expensive too. Others may have more conclusive numbers for you. Might be worth a call to Dan Lilja or any of the barrel makers who may have tested such things to a solid conclusion. Good luck. [img]images/icons/smile.gif[/img]
I've shot 80 in 95 Degree weather before having to pour cold water down the barrel. Accuracy had started to decline, but, not too bad. It was still shooting under 20" at 1000. It's a fluted barrel and when it got that hot I'd say the flutes actually were doing something because it was so hot. typically, noone get a barrel hot enough to utilize the cooling ability of a fluted barrel and it is said that by the time it gets hot enough to use the extra surface for cooling, it is allready way too hot. I agree.
Get a funnel and some plastic hose that you can jam in your chamber and pour ice water down it. Then patch it good to be sure all the water is out, clean as usual and go back to shooting. I'd quit after about 40 rounds because after that, you probably aren't learning much except how barrel heat disturbs the gun.
If you have something that you disassemble and reassemble enough times, sooner or later, you'll have two!