Does that mean you have a question?
Dave
Instead, I'll make it a statement.
A heavier bullet starts slower, extending the amount of time the powder heats/flames the throat. Faster twist slows down any bullet regardless of weight more than a slow twist will. Also, heavier bullets are usually used in conjunction with slower burning powders, further extending the time the heat acts on the throat.
And of course there are other factors that can contribute to throat erosion such as angle of bottleneck in the brass, neck length, etc.
I've had the opportunity to look down enough borescopes to see that the throat area is what takes the beating, not the lands further down the barrel. The throat will be long gone before we can ever wear out the lands.
Yhou're right, twist rate probably is not very significant taken alone, it's all the factors taken together.
Casey
