Re: Extra Metal on Long Range Rifles
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The barrel bedding block also does a couple other things.
1. Harmonically shortens the barrel to what is extending outside the block forward. For example, 30" barrel, with 9" block (extensive testing has shown this to be the best and max length) leaves about 21" sticking out front. The theory is short fat barrels are more accurate (easier to tune) than longer barrels.
2. Easy barrel changes. Simply unscrew the top block, lift the barreled action out and change barrels and clamp back in. No rebedding of the action required. Make sure that you use a "split" block. You can use a solid block that just has a hole drilled where the barrel is glued in but that is expensive and time consuming to change the barrel. The split block is the way to go.
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Iím not convinced that a short, fat barrel is more accurate than a longer one that's not very fat. The smallest groups of 10 or more shots I know of fired at 600 yards have been made with medium length and weight barrels. Same thing applies for 1000 yards. I know thereís been some 5-shot groups at those ranges that are pretty small and impressive.
Iím not sure that a proper epoxy bedding job has to be done each time the barrelís replaced. Having worn out three .30-.338 Mag. barrels in the same Devcon Plastic Steel bedding over an 8-year period, each one was tested for 1000-yard accuracy with 15-shot test groups; once when the barrel was new and again after about 600 rounds. The largest group was just under 7 inches.
A friend was watched check out four .308 Win. barrels in his Win. 70 based rifle one afternoon. He would remove the barreled action from the Bisonite epoxy bedding, clamp the barrel in a barrel vise, unscrew the action with a receiver wrench, put another barrel in the vise then refit the action clocking it in to the witness marks heíd put on each barrel when he fitted and chambered them. The rebarreled action was put back in the stock, all three screws torqued to 60 inch-pounds, then the rifle was clamped in the sliding carriage of a machine rest. After shooting a 20-shot test group at 600 yards, the rifle would be rebarreled and another test group was made; all using the same lot of ammo. All the test groups were from 2.5 to 3.5 inches. He put the barrel that shot the best back into the rifle.