I hate idiotic speculation.
The "pitting" in your bolt face, as a few others have noted, is gas erosion. In your case, it is caused by loose primer pockets.
- Why does it happen? People load considerably over SAAMI/CIP max pressure levels.
- Some brass cases, I won't name any names, are only good for 2 to 4 loadings at elevated pressure levels before primer pockets become enlarged. Depending on pressure this can happen on the first shot.
Here's what it isn't.
NOT a defect of the heat treat or metallurgy.
NOT primer "piercing".
A primer pierces or "blanks" where the firing pin indents the primer. The pressure levels inside the case cause the soft copper primer cup to shear, pressure levels overcome the energy of the firing pin and spring and fully compress them usually depositing the copper disk inside the bolt. Legacy AI rifles had 2.0 mm diameter firing pins like many other bolt action rifles. This was not an issue for about 3 decades until a significant number of owners started using AIs in competition and reloading to excessive pressure levels. In 2014 we reduced the firing pin diameter to 1.6mm on the short action and in 2019 we introduced the 1.6mm firing pin on the ASR/AXSR/AXMC-LE. On the magnums, this was in response to the rise in popularity of 300 Norma Magnum and the very high pressure levels this cartidge can and typically is loaded to. As a manufacturer, we have to take a reasonable position on how much pressure we design the firing pin system to tolerate before giving the user "feedback" in the form of signs of excessive pressure, such is loose primer pockets, pierced primers, and completely blown case heads. At 1.6mm you can blow the head off the case with softer brass before piercing a primer. One should consider this a hard knuckle rap to the forehead before cashing in your life insurance policy.
The dimples in the outer edge of the bolt head are from Rockwell hardness testing. Every AI will have them. It isn't a defect, it's a quality control measure along with proof testing.
The gas cutting won't effect the performance of the bolt, but if you want a new one they are available from Mile High Shooting Accessories and Accuracy International of North America, Inc.
-Scott
Well said, Scott.
So, dude who sold him the gun was loading too hot a load and by his own words, he did it about 90 times, and this is what caused the pitting....? Is there any other issues that could be present with the gun because of so many high pressure rounds being run through it?
Btw: I always appreciate when the manufacturers get in threads and give the factual data. Very interesting thread.
I don't want to speak for Scott as far as other things being damaged from primer leakage, but the gas leakage from the circumference of the primer will impinge on the extractor and ejector as the gas escapes and can eventually damage/weaken them.
The AI leaf spring extractor is a pretty beefy piece and probably much less susceptible to damage from gas leakage from primer failures than say a remington extractor, but even the AI extractor was probably not designed to be exposed to what was probably dozens of high pressure / high temperature gas leakage events in this particular rifle. Other parts "downstream" of the bolt head that were never designed to be exposed to hot gas leakage on a constant basis can also be eroded or damaged, but the bolt face, ejector, and extractor will take the brunt of the abuse.
Scott is 100% right this is *not* from pierced primers... primers that pierce at the point of firing pin contact will let the gas impinge on and erode the firing pin tip, firing pin hole in the bolt, and can deposit the small primer cup "plugs" inside the bolt and bind up the firing pin. Primers that pierce at the firing pin contact point won't leave a circumferential "trench" around the primer OD like on this bolt.
The damage on this bolt is from gas leakage around the circumference of the primer-- either loose primer pockets in the brass from soft brass, hot loads, or too many reloads leading to loose primer pockets (most common), undersized primers (not very common), or defective primers (also not very common.)
As I mentioned earlier several years back Winchester had several defective lots of WLR primers that had cups that were too thin and they would burn through/pinhole at the radius of the primer. This would damage boltfaces from the gas leakage. I had about 5k primers from one of the defective lots, and they absolutely trashed a friend's 22-250 bolt even with moderate loads. The pinhole leaks from these defective WLR primers were extremely damaging to bolt faces because all the gas leakage would be concentrated through a single tiny pinhole at the radius of the primer cup-- and that pinpoint gas leakage rapidly "torched" deep pits in the boltface. Loose primer pockets will also erode the bolt face from gas leakage between the brass and primer cup, but because the gas leakage from a loose primer pocket is typically spread around the circumference of the primer it is slower to erode the boltface since the gas leakage is spread over a larger area compared to the "pinhole" failures of the defective WLR primer cups. Either one isn't good, but based on firsthand experience I'll take a loose primer over a pinholing defective WLR primer any day.
While this rifle will still shoot with the crappy looking boltface, the pitting now leaves areas of the primer unsupported which can contribute to primers failing because the primers will try to flow/deform into those unsupported areas during firing.
As I and several others said way back on page one, the person that sold this rifle to the OP should be paying for a new bolt head-- and should also refrain from suggestions regarding metallurgy/hardness testing.
