11-28-2012, 01:21 PM
Drifter Wrote:I enjoy shooting small groups as much as anyone, but as a hunter, I'm mostly concerned with where the very first cold-bore shot lands.
Some bullets from some barrels shoot admirably from a warm barrel, but miserably from a cold bore left fouled by the same load. Hunting bullets, especially bonded versions, seem more likely to throw the first shot. Match bullets seem less likely to suffer from this issue. It pays to test if cold-bore shots are what's important to your application.
Drifter:
To be up front, I view all the stuff about 'cold bore' zeros to be more myth than fact. I believe the majority of variance from a zero is due to the shooter firing his first shot of that day, with all the baggage he takes to that shot.
If the barrel sucks, it will suck dirty or clean no matter the bullet. If the bullet sucks, it won't get better because the barrel is dirty, hot, or cold. This is because bullets that suck are generally not balanced well and a dirty or warm barrel won't change how the bullet was made.
Also, I haven't seen any indication that such a thing exists with barrels or ammunition ranging from service through match grade. I have seen hundreds of pages of 'cold bore' shot records and haven't seen a pattern that anyone can predict.
Finally, one shot won't change barrel temperature enough to have any meaning and one shot won't put enough fowling down the barrel to change anything, either.
What heat, cold, or humidity may do is cause problems between a receiver and a wooden stock which in turn may cause zero problems.
LR55