S.e.e. ??

[racepres]

Was gonna put this under case forming...But... Not Funny
documented to my satisfaction. I inadvertently put 26 grains of W748 instead of 36gr. into the 8X57 with 170gr Boolit
Double checked the charge in fact... physically, Not the Book ... Obviously
If yer gonna be Dumb...ya better be Tough...Or, Use a 98 Mauser.. Only My Pride, and Confidence in my Old Feeble Mind, were Shaken....Oh...And Nerves!!!!
Only thing I can come up with is S.E.E. Powder was definitely W748...charge was double Checked (even if Wrong).. old Mauser is Not any Worse for Wear!!!!
I never had anything like that, and been reloading since 1979 or so...
Be Careful You Old Farts!!!!... (maybe younger guys too)
Almost too embarrassing to Share... But... gettin old is about Sharing...

[BLAHUT]

?????????

[racepres]

?????????

Ok...Maybe Not SEE... What do You think Happened???

[Hannibal]

Can you post a few more pictures from other angles? Is the case exactly as it was when removed or have you done some cleaning/wiping on it?

Never saw a case head do something like that while in battery. Were you opening the bolt when this occurred? Something seem very odd.

[turtlezx]

i would think so how else would 10 grs under blow

[BLAHUT]

You state : I inadvertently put 26 grains of W748 instead of 36gr. : Lite load, blowing case ? Wrong powder ? Old and weak brass ? Head space ?
Was bullet stuck in barrel ? Plugged barrel ? Fired out of battery ? What little can be seen brass looks old and brittle ? ?????????

[Hannibal]

The thing is, if the rifle and barrel are undamaged yet the case head looks like that it couldn't have been in battery/bolt closed.

So either you had a hang fire and opened the bolt, the bolt wasn't in position/closed when fired or maybe ...... and this is a stretch but did the firing pin hang up and move forward when you started opening the bolt?

The last 2 situations would mean you definitely do have something wrong with your rifle.

[racepres]

Can you post a few more pictures from other angles? Is the case exactly as it was when removed or have you done some cleaning/wiping on it?

Never saw a case head do something like that while in battery. Were you opening the bolt when this occurred? Something seem very odd.

I can get more pics...tomorrow, or so.. case is at shop.
I believe the tearing etc you see happened when I forced (literally beat) the bolt open.. driving the case out after that was Not that big of a deal.. but, not for cleaning rod.. Dowel, and Hammer

You state : I inadvertently put 26 grains of W748 instead of 36gr. : Lite load, blowing case ? Wrong powder ? Old and weak brass ? Head space ?
Was bullet stuck in barrel ? Plugged barrel ? Fired out of battery ? What little can be seen brass looks old and brittle ? ?????????

Exactly as I stated... boolit exited.... Load Too Lite with Ball Powder!!! Nothing in barrel...I check religiously as we have Mud Daubers.
None of my Mausers can/will fire out of battery.. by now I believe I know enough to Close the Bolt!!!
Old brass...Yup... discolored but... the rest of that lot is still working Fine with 36.0 grains vs 26!!!
Headspace???? As Many cartridges as I have Fireformed... I sincerely Doubt headspace can/will/could do anything remotely resembling that!!

Nope... I'm sticking to SEE, caused by too light a Charge, until ??? a plausible answer surfaces...
Again nothing wrong with that Old VZ24!!! Still functions very well indeed...
And... the case got mis-shapen and torn opening bolt (Mausers extractors Are Tough as Chicken Lips)
this aint no Remchester.

[country gent]

Looks like the case gave out into the extractor cut in the bolt.

How was the bolt lidt. I would consider detonation. They didnt recommend light loads for a lot of the Winchester ball powders.

[racepres]

Looks like the case gave out into the extractor cut in the bolt.

How was the bolt lidt. I would consider detonation. They didnt recommend light loads for a lot of the Winchester ball powders.

Probably exactly what happend when the Case head let go.. Bolt discolored terribly (black, Not white like I expected), wiped off..
Edit; L>ooking again at rifle...silly me... no Extractor "slot" on a Mauser... but, thinking brass "flowed" out the unsupported face where the Ctg would come up from magazine..
I double checked just now, and that brass, does appear discolored rather badly...and though 36.0 gr should be a light load, the primer pockets seem loose... prolly retire that brass...as This was an unpleasant experience...and a reminder...My Mind Aint what it used to be!!! Gotta slow down.... smell the coffee...
I am currently wondering if I could reproduce such an event with lighter than recommended Charge... From a Distance If I tried it...

[LAGS]

I have seen several firearms that were damaged by Too Light of a reload.
It seems with some powders.
If the case is not up to the Minimum Charge for that powder.
The powder Flashes Over and creates excessive pressure.
A friend had that happen with a 22-250.
It blew the bolt apart and cracked the receiver.
To avoid that with intentional light loads , you have to put a filler in the case to take up the extra air space and keep the powder back against the primer.
Usually minimum loads are like 60% of the case capacity.

[murf205]

I had a 22-250 pull that stunt with 4320 and a 70 gr Speer semi spitzer. Smoke from the action and primer fell out with a middle of the road charge. After a long bit of searching, it turns out that the very long bearing surface of that bullet raises pressures very quickly. I still use that bullet in my 223 but I sneaked up on the load from WAY behind and I use BL-c2 now. I'm not sure what caused your event but those thrills, we can do without. WEAR THOSE GLASSES.

[racepres]

I have seen several firearms that were damaged by Too Light of a reload.
It seems with some powders.
If the case is not up to the Minimum Charge for that powder.
The powder Flashes Over and creates excessive pressure.
A friend had that happen with a 22-250.
It blew the bolt apart and cracked the receiver.
To avoid that with intentional light loads , you have to put a filler in the case to take up the extra air space and keep the powder back against the primer.
Usually minimum loads are like 60% of the case capacity.

No Fillers for me...Ever...and I would Not claim that (X) percent full was somehow magic...as 12gr of Red Dot with a Non gas check 170 boolit works very well indeed in that 8X57, again... no Filler.. Tho 26 gr of 748 is prolly around 50% of available space in that loading..
I try to treat Ball Powders with more respect...generally about 75 - 80% of available space..I just blew this one Ctg...actually more than one, but I pulled the remainder and re-charged appropriately!!!

I had a 22-250 pull that stunt with 4320 and a 70 gr Speer semi spitzer. Smoke from the action and primer fell out with a middle of the road charge. After a long bit of searching, it turns out that the very long bearing surface of that bullet raises pressures very quickly. I still use that bullet in my 223 but I sneaked up on the load from WAY behind and I use BL-c2 now. I'm not sure what caused your event but those thrills, we can do without. WEAR THOSE GLASSES.

Been wearing glasses since I arrived "Over the Hill", courtesy VA Thank You...

[405grain]

Just an FYI for those who suggest that this was caused by the rifle discharging while the bolt was partially open: 98 Mauser's are designed so this won't happen. There is a slot forged inside the bolt body that mates with a spade shaped extension on the face of the flange on the firing pin which retains the firing pin spring. Unless the bolt is fully closed the firing pin cannot move all the way forward, and the firing pin tip cannot extend beyond the bolt face.

An under charge of a slow burning ball powder can result in a pressure spike. This is less likely with fast or medium burning rate powders, but can occur with with small charges of slower powders. Under these circumstances the powder charge does not ignite uniformly. The abnormal ignition causes the pressure to build too slowly for proper burning. As the pressure finally builds up to the point that the powder charge finally fully ignites, this can cause supersonic shock waves to develop inside the case. It is these shock waves which can cause a rapid compression of the burning powder charge (which can cause an exponential increase in burning rate), and create a feedback loop which generates significant over pressure inside the cartridge.

The failure mode of the OP's cartridge is exactly what would be expected in a 98 Mauser. Unlike, say, a Remington model 700, the case head in a Mauser is not fully supported. With pressures that cause brass to flow, the case head can separate just in front of the extraction groove. The gas from this rupture would flow both down into the magazine well (where if it had swollen the magazine it would have probably cracked the stock), and also back the feed rails towards the shooters face. The flange on the front of the bolt shroud would have diverted the bulk of this gas, and a large portion of it would have passed out through the thumb cut for the stripper clips. This incident is a fine example of the excellent gas handling characteristics of the 98 Mauser, and also a reminder to remain diligent when reloading.

[Hannibal]

Just an FYI for those who suggest that this was caused by the rifle discharging while the bolt was partially open: 98 Mauser's are designed so this won't happen. There is a slot forged inside the bolt body that mates with a spade shaped extension on the face of the flange on the firing pin which retains the firing pin spring. Unless the bolt is fully closed the firing pin cannot move all the way forward, and the firing pin tip cannot extend beyond the bolt face.

An under charge of a slow burning ball powder can result in a pressure spike. This is less likely with fast or medium burning rate powders, but can occur with with small charges of slower powders. Under these circumstances the powder charge does not ignite uniformly. The abnormal ignition causes the pressure to build too slowly for proper burning. As the pressure finally builds up to the point that the powder charge finally fully ignites, this can cause supersonic shock waves to develop inside the case. It is these shock waves which can cause a rapid compression of the burning powder charge (which can cause an exponential increase in burning rate), and create a feedback loop which generates significant over pressure inside the cartridge.

The failure mode of the OP's cartridge is exactly what would be expected in a 98 Mauser. Unlike, say, a Remington model 700, the case head in a Mauser is not fully supported. With pressures that cause brass to flow, the case head can separate just in front of the extraction groove. The gas from this rupture would flow both down into the magazine well (where if it had swollen the magazine it would have probably cracked the stock), and also back the feed rails towards the shooters face. The flange on the front of the bolt shroud would have diverted the bulk of this gas, and a large portion of it would have passed out through the thumb cut for the stripper clips. This incident is a fine example of the excellent gas handling characteristics of the 98 Mauser, and also a reminder to remain diligent when reloading.

Could someone direct me to or post an image of such a chamber? This is something new to me so I stand corrected. Pardon my mistake and any confusion I caused.

Learn something new every day. And sometimes something old is new.

[Hannibal]

I can get more pics...tomorrow, or so.. case is at shop.
I believe the tearing etc you see happened when I forced (literally beat) the bolt open.. driving the case out after that was Not that big of a deal.. but, not for cleaning rod.. Dowel, and Hammer


Exactly as I stated... boolit exited.... Load Too Lite with Ball Powder!!! Nothing in barrel...I check religiously as we have Mud Daubers.
None of my Mausers can/will fire out of battery.. by now I believe I know enough to Close the Bolt!!!
Old brass...Yup... discolored but... the rest of that lot is still working Fine with 36.0 grains vs 26!!!
Headspace???? As Many cartridges as I have Fireformed... I sincerely Doubt headspace can/will/could do anything remotely resembling that!!

Nope... I'm sticking to SEE, caused by too light a Charge, until ??? a plausible answer surfaces...
Again nothing wrong with that Old VZ24!!! Still functions very well indeed...
And... the case got mis-shapen and torn opening bolt (Mausers extractors Are Tough as Chicken Lips)
this aint no Remchester.

Sorry for my mistake. As I said above I learn something new every day. Glad you are ok.

[rockrat]

Had that happen with a S&W 29, using AA#9 and too light a charge. Just a "pop" and a pinkish flash as the top of cylinder departed the gun.

[405grain]

The bottom of the bolt face on a Mauser is open so that it can strip cartridges from the magazine. There has to be a small open gap between the breech face and the bolt face for the claw on the extractor to reside. Because of these properties, the cartridge base is supported pretty well, but is not fully supported. For the best explanation on how the safety feature on the firing pin works, check out this video:
https://www.youtube.com/watch?v=XnHMBrtQNtE

Editing this post because I just had an afterthought. When I load cast rifle cartridges wild ball powders (like BLC-2) I use magnum primers. I think that this produces better ignition with ball powders. Generally, the fuller the case is the better.

[racepres]

405 has done a much better job of Explanation than I could have.. The brass certainly "flowed" such that it took a "club" to open the bolt!!! Making case Forensics difficult. Unlike rockrats experience... this was quite loud, and again like 405 says.. gasses went out the side (probably deflected by the bolt shroud, but I cannot "replay" it) and certainly down into the mag well...as black soot was evident there too.
Unnerving as all get out.. Again... Love My Mausers... Tho I may should treat them Better!!!!

[Hannibal]

The bottom of the bolt face on a Mauser is open so that it can strip cartridges from the magazine. There has to be a small open gap between the breech face and the bolt face for the claw on the extractor to reside. Because of these properties, the cartridge base is supported pretty well, but is not fully supported. For the best explanation on how the safety feature on the firing pin works, check out this video:
https://www.youtube.com/watch?v=XnHMBrtQNtE

Editing this post because I just had an afterthought. When I load cast rifle cartridges wild ball powders (like BLC-2) I use magnum primers. I think that this produces better ignition with ball powders. Generally, the fuller the case is the better.

OK. I understand all that and how it's supposed to function. I was hoping someone has a barrel outside the action or a cut-away view so I can see the unsupported area that's being discussed.

I appreciate your help guys. I'm always happy when I can increase my knowledge and understanding.