First, I want to thank Buffalobob for tracking me down and making me aware of this forum. Long range hunting huh? Sounds like fun to me.
Anyways, I will ad this forum to my lists and lurk around from time to time to see if anyone needs help that I can provide.
Regarding the situation on this thread, the 6mm 115 gr VLD that have a closed looking hollow point are the result of jackets that had to be washed more than once. We make bullets in California and the rules about cleaning solvents are clear. No solvents. We have to use water with particular types of soap. Then we have to deal with the brilliant California legislature who created a law that says the water we use must be returned to the drain in a cleaner condition than when it came out of the tap. That's right I said cleaner than their own city tap water.
This compels us to use processes that are sensitive. From time to time these soapy water handling processes don't work properly and we are forced to rewash jackets (and/or bullets). In this case the jackets used to make the 6mm 115 gr VLD were washed more than once resulting in the mouth (pinch trimmed) developing a small flattened burr. This burr is what fills up the hollow point. If you take a needle or one end of the staple you will see that it is easily pushed aside. You do not need to push this burr aside on every bullet as it will have no affect on trajectory, accuracy or expansion.
The tooling mark you are reffering to is the other side of the burr rolling down the jacket as the bullet is forming in the ogive die. It is the slug mark that is left behind when the burr is washed away as the jackets are cleaned (hopefully once). This mark also has no affect on trajectory, accuracy or expansion. It is the unavoidable result of the challenge we face in dealing with the controls over our cleaning processes.
Let me be clear that we know exactly what you are refering to and this does not have any negative affect. If it did we would not have allowed the bullets to leave our shop.
I hope this helps and I will be checking in from time to time to see if I can assist when it is appropriate to do so.
To strengthen your shooting skills go to the range.
To strengthen the shooting sports take a new shooter with you.