It was actually in the bolt, under the extractor. They get there a lot.

I actually didn't touch the bolt face with the cutter. That was just the cratex polish. It wasn't pitted, these things are REALLY hard.

Hole was reamed with a #51 reamer and I turned and dressed the pin to .064".

I'll drop it in the mail tomorrow.

Nice sticks, nick!  Last year I said I'd cerekote my mega. Now I'm saying this year and not placing bets yet.


I'm headed to the 'range' now with this...

Results are incomplete, but next week I'll have some time to refine some of this and really get dialed in.  So far however, I'm VERY encouraged at the changes.

Here is a picture of a few random pieces of brass pulled from the tumbler after having several loads of IMR4350 through them.

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Here is a picture of two brass from a load of 44.4gr of Superformance, which although not a 'hot' load is definitely one that I couldn't even come close to in the past.  A very mild load of Superformance in the past with a 123gr AMax was getting very significant primer flow, moreso that the first pic here.

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Results were terrific across the board.  I stumbled across some some H4350 last week and I also loaded the Superformance to see what it would do.  40.2gr of H4350 gave me a group of three about 1/2" across at 175yds with a std dev of 21fps.  Bullet is a 140gr AMax set 0.015 off the lands.

Other loads with the H4350 were also quite impressive, but not quite that good.  The next load hotter, 40.5gr, opened up to about 2.1", and the lighter loads were about 3/4MOA, so I think pretty close to 40.2 will be the sweet spot.

More impressive was the changes in my ability to shoot Superformance.  That powder is readily available at almost every store I walk into, and I've got 8lbs of it here.  I only tried two loads just because I wanted to see if it was even safe, and it is, so I'll be doing a LOT more work with that over the next few weeks.

I did a light load of 44.0gr of Superformance and got an average velocity of 2730, which is pretty similar to H4350 velocities in spite of this powder being intended to provide more velocity.  Std Dev was nice at 36fps, much better than my original results with 123gr bullet and std primer.  I think this powder is harder to light off so the heavy bullet and mag primer are very helpful.  Recoil is a lot more and I could definitely turn down my gas block with this powder.  Accuracy was about 1.25MOA.

The heavier load was 44.4gr (max is 44.7) and with this load I had near 2800fps, std dev of 9.8fps (NICE!  The only time I've done better in my life was an H4350 load over a 123gr AMax in this gun that did 7fps) and shot about .75MOA.


Looking forward I now have two powders that are completely viable, three if you count IMR 4350 which surprisingly did better today than normal getting 7 shots into just over .7MOA but with higher STD DEV and lower velocities.  I'll be fine tuning the H4350 load with around 40.2gr and around .02" off the lands, as well as the 44.4gr of Superformance about the same distance off the lands.

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Here is one last pic, I should have taken a few more while I was shooting but I get going and forget about updating the interwebs.

Thanks for the help Ben!  Amazing the difference in primer flow.  I'm wondering if the improvement on my IMR load is also attributed to the change on the bolt, my group shrunk by about 1/2" at 175yds and I didn't change anything, in fact these were the last rounds I had loaded from months ago of that load, and use a Sierra bullet.

Glad to see your new bolt worked out SCW.  I got out to the range today with my freshly reamed chamber and JP bolt.  












 

Nice shooting!  I meant to reply to your IM but I hate the IM windows on my phone and that's where post pics from.

Did your smith tell you how far he reamed the chamber?  I have found that with both the Hornady AMax and Match bullets the distance to the lands is well within the mag length.  With the Barnes Match Burners I end up about 0.060" off the lands when I'm at full length on the magazine.  With the AMax I'm actually several thousandths short of the mag length, but I don't think I'm quite short enough to fit in a PMag.

This is all done with the Hornady/Stoney Point OAL gauge, which may or may not be giving the right values for a semiauto, but it's still the best I can do.  I'm going to play with seating depths a bit now that I've got a few powders that are working and I'm not blowing primers.  

In his words, he "kissed" the chamber with a reamer. He said that even though it was in spec on the very tight side, he has seen opening it up just a touch work wonders for pressure issues. I haven't measured anything for seating depth yet as I wanted to make sure it ran with factory ammo first. The bolt itself may have done the trick, but those blown primers made me pretty nervous...

this is the enhanced firing pin that JP sent with the barrel as well as a headspace matched bolt.  Test fired with no pressure sign on hornady match 120 amax.  I forgot to bring allen keys out like an idiot so I will be making another trip to get the gas tamed a bit.  Hopefully glass will be in on tuesday.

Huh. I wonder why they turned down the middle.