Well my duck hunt got cancelled so I had some time to work in the garage tonight to try out some of the things that everyone was kind enough to take the time to suggest.
I did a thorough cleaning of the bore and chamber until it was spotless.
I checked the distance from the head to shoulder datum both with and without a bullet seated and there was no measurable difference in the length that would indicate that I am compressing the shoulder with the seating die.
I continued to seat the bullet down until the entire bearing surface was below the case mount and the bolt closed easily (2.0620" base to ogive). The markings on the bullet are from seating depths longer than the one shown. Whatever is making the marking appears to be the same cause of the stiff bolt closing.
I then pulled the bullet and tried to determine at what point the bolt stiffness disappeared (2.0785"). At 2.0875" the first bolt close is a little stiff but subsequent closings gets easier. I would say this one is right on the edge of where the problem is starting
I then loaded another round at 0.010" short of where I measured the lands to be and steel wooded the bullet. I played around a little with seating depth but nothing extreme. I am getting a mark on the top side of the projectile that covers just under 90-degrees. I believe there may be a burr in the chamber that is rubbing against the bullet and once the extractor grabs the bullet it is twisting the bullet along the burr and causing it to score around circumference of the bullet as I close the bolt and causing the stiffness. Not until I get the bearing surface below the neck to I avoid the contact.
Even seated fairly deep the relation of the marking on the bullet and the case neck remains the same
I also tried a 165gr Hornady A-Max in addition to the 168gr Sierra Match King which I have done most of my testing on but haven't done extensive measuring to know the exact point where an A-Max hits the lands. I didn't get the scoring (or any other clear marking) on the A-Max but the stiffness was still there.
What I don't know now is what the proper next step is. I suppose I need to order a casting kit and make a cast of my chamber so I can measure things. Are the casts accurate to within 0.01" or do they expand/contract enough that the measurement won't be accurate enough for my needs. I also plan to call Savage to talk to someone in their technical support department. I called today but they needed the serial number which I didn't have at the time. I fear their default answer is going to be to send it back and they will end up drilling out or replacing a barrel that I believe is quite accurate. If that ends up being the only solution then I suppose that's what I will have to do.
How long does throat erosion take to erode a few thousandths? The gun has only 25 rounds through it. Would getting another 75-100 rounds down the barrel with a reasonably light load potentially solve my problem? Thanks to everyone for suggestions so far and I appreciate your continued help.
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