Today's guinea pig was the 6x45 Contender with a plain base bullet. The last time I shot this bullet it was grouping decent at 1800 fps but couldn't even stay on the target backer when velocity was increased to 2000 fps. There was absolutely no sign of leading in the barrel, so I couldn't figure out what caused the bullet to fail ? Maybe the water tank would provide answers?
I fired 2 shots with the 1800 fps load. There was no sign of yawing or skidding. The only thing remotely suspicious is that the corner of the base is eroded in some spots.
2 shots with the 2000 fps load. Once again, no sign of yawing or skidding, but the corner of the base is eroded.
As always, I can't be certain whether the erosion occured inside the barrel or inside the water tank. But if it tumbles in the tank, usually one side is eroded while the other side is protected. The 2000 fps bullets had erosion around the entire circumference of the base, suggesting that it happened inside the barrel.
I do not know if that tiny bit of corner erosion had anything to do with the loss of accuracy. But I don't see anything else wrong. roll: