Howard Roark
Member
With the topic of how long will XYZ caliber barrels last I recently checked a couple of barrels for throat erosion.
First, my .223 AR match rifle started loosing accuracy at the 300 and 600 yard lines. After shooting an 8 on the 600 yard NRA MR target I decided to check things out. The barrel was a SS Douglas with about 3300 rounds down it. The throat had eroded .138 thou. Time for a new barrel. I rebarreled with a new Hart and have not shot the 600 yard line yet but on a 600 yard target reduced to 300 yards it shot a 199-12x. I'll call it fixed.
Second, I checked the throat on my .260. After 1000 rounds it has eroded .007 thou. 500 of these rounds were shot with VV N-160 and after finding that IMR 4350 shoots much better groups I switched. The erosion most likely will accelerate due to 4350 being a bit of a hot burning powder. The increase in accuracy is worth it.
Edited to add:
I didn't post this as wonderment of erosion, but to put hard numbers on real world testing.
First, my .223 AR match rifle started loosing accuracy at the 300 and 600 yard lines. After shooting an 8 on the 600 yard NRA MR target I decided to check things out. The barrel was a SS Douglas with about 3300 rounds down it. The throat had eroded .138 thou. Time for a new barrel. I rebarreled with a new Hart and have not shot the 600 yard line yet but on a 600 yard target reduced to 300 yards it shot a 199-12x. I'll call it fixed.
Second, I checked the throat on my .260. After 1000 rounds it has eroded .007 thou. 500 of these rounds were shot with VV N-160 and after finding that IMR 4350 shoots much better groups I switched. The erosion most likely will accelerate due to 4350 being a bit of a hot burning powder. The increase in accuracy is worth it.
Edited to add:
I didn't post this as wonderment of erosion, but to put hard numbers on real world testing.
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