Unlikely to be overall length jamming in the lands. The SAAMI spec for COAL is 3.34" and you are loading 3.37". That's not a lot over spec and as you say, you've shot over a 1,000 rounds through it already. The throat will have worn even longer and presumably you've been loading similar lengths, and used the same bullet through it already.
With respect, you started the thread saying it was a 168gn bullet and later said it was 165gn. In your shoes I would go back to basics and weigh and measure the bullet. Confirm it is what the box says it is. Same with the powder and how much is going in the case. Check fired cartridges against how much you are bumping the shoulders back. Something has seriously gone wrong and it might be a simple mistake.
With respect, you started the thread saying it was a 168gn bullet and later said it was 165gn. In your shoes I would go back to basics and weigh and measure the bullet. Confirm it is what the box says it is. Same with the powder and how much is going in the case. Check fired cartridges against how much you are bumping the shoulders back. Something has seriously gone wrong and it might be a simple mistake.