I have a battery powered tire pump, and I put that down the muzzle of the gun and turn it on to get it cooled down quickly. Works. One fellow, Richard, over on the Savage forum takes an Aluminum rod that he bought from Home Depot and inserts it in ice water, wipes it off and shoves it down the barrel.
That cools the barrel real quick. You have to wipe the rod clean of excess mosture, especially the end. He had 1 misfire because he didn't wipe the end off. He said the cold travels up the rod so when it put it back in the ice water it is cold by his next shot. The guys over there are Accuracy shooting and they go to great lengths to shoot 5/8" groups at 100 yards and 1" groups at 200, and yes they do that all the time.

Sears has them here: http://www.sears.com/shc/s/s_10153_12605_Automotive_Tools+%26+Equipment_Air+C ompressors+%26+Inflators?psid=15472678&sid=ISx 20070515x00001a

they look like this.

Here is Richard's latest barrel cooler:
http://dougva.proboards34.com/index.cgi?board=Savage&action=display&thre ad=9675

Chap