12-05-2012, 11:44 AM
I am one of those superstitious folks that believes a cold clean bore impact location can be different from the following shots. I have observed this with one of my service rifles. It will always shoot an inside 8 at 5:00 the first shot of the day from a clean bore at 600 yards. The next shot will be an outside 10 at 5:00 and the following shots all X's if the shots are executed correctly. Last year I won four cold bore X challenge coins at Port Malabar with that barrel. That means I compensated for the first shot correctly on four different days in registered matches.
The barrel I have this year does not do this. It will shoot an X first shot clean and cold but does move up 1/2 moa as it warms up on about the 8th shot and stays there through the remaining shots of a 22 shot string.
Both of these are Krieger 1:7.7 twist 20" service rifle barrels chambered with a Wylde .223 chamber.
The AMU also believes that a cold bore / clean bore can have a repeatable point of impact different from subsequent group centers and teaches to verify this over multiple days. http://www.shootingusa.com/PRO_TIPS/USAM...mu6-3.html
Bob
The barrel I have this year does not do this. It will shoot an X first shot clean and cold but does move up 1/2 moa as it warms up on about the 8th shot and stays there through the remaining shots of a 22 shot string.
Both of these are Krieger 1:7.7 twist 20" service rifle barrels chambered with a Wylde .223 chamber.
The AMU also believes that a cold bore / clean bore can have a repeatable point of impact different from subsequent group centers and teaches to verify this over multiple days. http://www.shootingusa.com/PRO_TIPS/USAM...mu6-3.html
Bob