I have been doing a fair bit of reading on the subject and have been getting mixed answers so I thought that I would ask the question of those who shoot F class etc.
Which is the better of the two a 26" or 30" barrel?
I have always believed that the longer the barrel the better but in real terms how much velocity and accuracy would you lose over say 600 plus meters between the two different lengths iin a 6.5 Creedmore?
If you’ve burnt all of the powder, excessive barrel length would probably slow things down.
Short answer enough to make a difference. You would be giving you opponents probably a 15% advantage. You would likely lose 150-200 fps which at the speeds you want / need to push them its significant.
The common barrel profile for a 6.5 is a straight 1.25 inch from action to crown. The 30 inch is also the norm for F class. not much is gained going to a 32 inch.
It may also not handle as well as it could. even though the recoil is not really a huge issue. You are allowed a 10kg rifle in the class that rifle would be in. Best to use all that weight in the right areas.
Some info re the Rifle setups that will be used by the F open class competing in the next world cup
When the friction from the barrel is greater than the pressure being built up behind it. Or something like that. 30 inches seems to be the sweet spot when the best type of powder and load for the bullet weight combination all seem to burn in that length loading the case to 100% also seems to be a sweet spot regarding ES.
I have loaded or I should say overloaded a case to watch the expected increase in MV and there is a point when it goes from a nearly linear slope to a leveling off ie more powder does little to increase MV.
I have a 28 inch and 30 inch 308 and can shoot the exact same load in each ( same reamer barrels made and chambered by same person just weeks apart) the MV in the 28 inch is 50 fps slower it is also a slightly less accurate gun