Blew up a gun ... UPDATED with possible solution
UPDATE: Please see the new picture:
http://i9.photobucket.com/albums/a67...difference.jpg
Well I said I was big enough to admit if I was at fault; one user suggested a contaminated powder dispenser. I really doubted this but was happy to investigate. I got around to pulling the remaining loaded rounds today; look what I found in one.... circled in red is the obvious difference between what I believe was 2400 on the left and WC867 on the right. Notice the chopped, flat appearance of the 2400 flake vs the globular round appearance of the 867. How I missed this is beyond me; I do not leave powder in the hopper, but apparently I did this time! I found one round with 2400, one with a mix, and the rest were 'normal.' Of course, now I have to consider what to do with the powder. I don't trust just pouring it out as up to 150 gr of 2400 might have been returned to the 8lb jug while I was dialing in my charge. I suppose I COULD carefully cut off the jug just above the powder level and remove the whole top half of the powder, a good 2-3 pounds, to make sure none of the 2400 was blended in... but for $49, I think I will just toss it to be safe.
Anyone with Quickload want to figure the pressure of 47 gr of 2400 with a 200 gr bullet in an 8mm? That was what was in the case, apparently being a little lighter by volume than the 867.
Finally- I didn't mention this earlier; but I DID hit the target- and there is no leading in the bore!!!! A testament to Felix and his lube that apparently even 100,000ish PSI and an unknown velocity (I'd guess 3-4000 fps) didn't lead the bore. :bigsmyl2:
First: I have to admit I'm eating a little crow here. I had previously assumed that anyone who blew up a gun MUST be doing something wrong- and maybe I was, but for the life of me, I can't figure out what happened! I'm ok, a few pieces of powder burnt my cheek and I chipped one lens in my glasses, but was rattled to say the least.
Gun: Portuguese Mauser-Verguiero, 8mm. I had shot this gun hundreds, perhaps thousands of times before, with all manner of cast, jacketed, and surplus rounds (never turk as it is a bit hot).
So I go out, fire 15 rounds of my 'go to' load of 18 gr of Alliant 2400, with excellent accuracy. This gun headspaced fine, and never had sticky bolt lift.
I then go to a new load- awhile back I got 2 jugs of surplus cannon powder from wideners, 1 jug of 872 and 1 of 867. I was assured on many threads here that you CANNOT stuff enough of these into a case to cause issue, and previous experiments had borne that out. I have fired 50, then 55 grains of this powder in other 8mms with this bullet with no issues, lots of unburnt powder, and so I went up a notch. I have mainly been working with the 872, but this season started on the 867 and found it to perform largely the same. So I filled an 8mm case to the base of the neck- about 60 gr- with WC 867. Primed with a mag primer, firing a 200 gr NOE bullet sized to .325", gas checked, lubed with Felix lube, ACWW. Fired one round. Normal report, normal recoil, no issues as regards to anything. Fired case showed normal pressure signs. Still a few unburnt powder kernels in the case when I tapped it, but fewer than before. I was actually feeling rather happy, thinking that enough powder had finally been reached to eliminate most of the unburnt mummies. Bore on this gun slugs to .324".
Second round: BOOM! As the smoke cleared I noticed in order: 1. My glasses were covered in soot, grease, and chipped. 2. Gun was now lying on the ground in front of me. 3. A piece of wood was blown out of the side of the stock below the gas escape hole. 4. I was bleeding from 3 small cuts to the cheek, 2 to the nose, one to the eyebrow, and one to the forehead. 5. I'm ok. Wounds are superficial. 6. Bolt has been re-cocked by the force of the explosion. Ejector spring is bowed out. 7. Bolt won't open.
I took the gun to my smith who works just down the road. He managed to get the bolt open by taking off the barrel and trashing what was left of the extractor. Further observations: 8. Case is totally trashed, primer spit, turned into a flat disc. 9. Atomized brass is everywhere. 10. There is a small crack in the receiver by the gas escape hole. 11. The lower lug was set back into the receiver about 1/32". Less above, but still noticeable. 12. Part of one lug was sheared off. 13. Part of the bolt shroud was fractured and missing.
I have no idea where any of these parts went.
See pictures below. Please tell me what you think happened. I have a theory but want to hold off so not as to spoil your speculation.
Be warned about the WC867 powder...
This is the type of bullet I was firing:
Image deleted as I can only post 10 max.
This is the case fired beforehand with the same load that destroyed the gun. Note no issues:
http://i9.photobucket.com/albums/a67...i/SAM_0017.jpg
The first thing I noticed- the wood missing from the stock:
http://i9.photobucket.com/albums/a67...i/SAM_0002.jpg
The remnants of the case in the barrel:
http://i9.photobucket.com/albums/a67...i/SAM_0007.jpg
The flattened primer:
http://i9.photobucket.com/albums/a67...i/SAM_0016.jpg
The crack in the receiver and the lug set back on the right and left sides of the pic, respectively:
http://i9.photobucket.com/albums/a67...i/SAM_0015.jpg
Partially sheared bolt head lug. Note it didn't shear at the base of the lug, which was taking the pressure, but rather appears to have been cut by the hot gas blasting over it; though I suppose the sudden impact might have just shattered it unpredictably:
http://i9.photobucket.com/albums/a67...i/SAM_0022.jpg
Sheared off shroud:
http://i9.photobucket.com/albums/a67...i/SAM_0019.jpg
Bowed out ejector spring:
http://i9.photobucket.com/albums/a67...i/SAM_0023.jpg
Let me know what you all think.