Zermatt - rather funny

#2
Soo, guess what they told me!!

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“No a problem. Send it in and we’ll test it then replace the needed parts.“
 
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#4
My guess is they told you that you aren't qualified too anneal brass or reload rifle cartridges.

But they are usually nicer than I am.
 
#5
Supersubes said:
Ok, lets hear the story.
Click to expand...
It was a beautiful sunny day in Alabama. While engaging a 1200 yard target with the most prefect 90 degree trigger press you have ever seen, a louder then normal boom went off. “IMPACT” belted from the RO. In my head, I knew something was not right. I proceeded to clear the rifle only to find a very heavy bolt. After a couple of taps, the bolt came free and fell complete out of the rifle! Oh, what a day my friends!

While I’m not completely ruling out an overcharge on my part, I do find it weird that I had a hit at 1200 yards when it happened. I would imagine an overcharge to send my bullet any where but the target. I was using premium brass on its third firing so I didn’t suspect any issues there. After talking to a couple of smiths, they believed the chamfering on the chamber was cut too large which left the case unsupported and lead to case head separation. Edit: after further investigation, it’s seems the Alpha GT non OCD brass more at fault with thin web and soft brass.


Old camber (brass still in chamber) vs new
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E4442B06-D286-4FEC-8A7A-C93C90FB3431.jpeg
 
Last edited:
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#7
drwood96 said:
It was a beautiful sunny day in Alabama. While engaging a 1200 yard target with the most prefect 90 degree trigger press you have ever seen, a louder then normal boom went off. “IMPACT” belted from the RO. In my head, I knew something was not right. I proceeded to clear the rifle only to find a very heavy bolt. After a couple of taps, the bolt came free and fell complete out of the rifle! Oh, what a day my friends!

While I’m not completely ruling out an overcharge on my part, I do find it weird that I had a hit at 1200 yards when it happened. I would imagine an overcharge to send my bullet any where but the target. I was using premium brass on its third firing so I didn’t suspect any issues there. After talking to a couple of smiths, they believed the chamfering on the chamber was cut too large which left the case unsupported and lead to case head separation.

Old camber (brass still in chamber) vs new
View attachment 7861699
View attachment 7861701
Click to expand...
What kind of barrel vise is that ?
 
#15
drwood96 said:
Annealeez
Click to expand...
What he’s getting at is that its possible to over anneal the necks. The heat conducts into the web, which anneals it as well.


I think your kaboom barrel has way too much chamfer. Hard to tell what the angle is from a pic, or how much clearance the breech face had from the bolt nose. If the tenon was short(lots of clearance), that would only add the problems if the chamfer was too large.
 
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#16
Why did the bolt fail at the cross-pin? Isn't that an unloaded item during firing unless the bolt lugs displaced the engaging surfaces on the receiver? Or did it break because of the force required to unlock the bolt?
 
#21
No it happens often enough when you obliterate the primer on a full house (or bonus pressure) load. The firing pin becomes a plunger and flies backwards at mach Christ under pressure from said gas until it bottoms out, and the abrupt stop overloads the thin portion of the bolt head which is at that point the glue holding everything together between the bolt lugs and the now rearward pushing firing pin.
 
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#22
It's hard to tell if the chamfer is "too large" from a pic like that. Depending on the cartridge, angle of the chamfer, and actual depth of the chamfer, the case may or may not have been well supported.

I have some barrels with pretty wide chamfers that still have full support of the case web.
 
#23
Ledzep said:
No it happens often enough when you obliterate the primer on a full house (or bonus pressure) load. The firing pin becomes a plunger and flies backwards at mach Christ under pressure from said gas until it bottoms out, and the abrupt stop overloads the thin portion of the bolt head which is at that point the glue holding everything together between the bolt lugs and the now rearward pushing firing pin.
Click to expand...
Thank you for the explanation, that makes sense
 
#26
Dai Bando said:
My bet is you over annealed and softened the case head. Do yourself a favor and trash the lot.
Click to expand...
You’ll have to really torch the brass to heat the case head/web that much to fail, assuming normal pressures. At that point, the wheels would be stick to the brass.

I’ve already replaced them.
 
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#27
UpSideDown said:
Why did the bolt fail at the cross-pin? Isn't that an unloaded item during firing unless the bolt lugs displaced the engaging surfaces on the receiver? Or did it break because of the force required to unlock the bolt?
Click to expand...
The lugs did there job containing the explosion and while the pressure is released via the ports. My guess is the energy traveled down the bolt head and broke at the weakest point with the thinnest material.
 
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#37
reubenski said:
Like a champ. No damage to the scope, trigger, or chassis. That action is locked up like a bank vault. The barrel is a CF. It was setback and shoots fine. That was the very first round down it. I mixed up AA#7 and Ramshot TAC loading 6.5 Grendel. 28gr of Accurate#7 in a Grendel....
Click to expand...

Dang. Any idea what kind of pressure that would be?
 
#39
Knocked the bolt stop flying, damn near sheared the bolt handle.... You won the lottery that day my friend.

I once found 2 jugs of powder on my bench at the same time. I dumped the entire hopper, and pulled almost 50 rounds and dumped that too. I haven't made that mistake since.
 
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#45
drwood96 said:
It was a beautiful sunny day in Alabama. While engaging a 1200 yard target with the most prefect 90 degree trigger press you have ever seen, a louder then normal boom went off. “IMPACT” belted from the RO. In my head, I knew something was not right. I proceeded to clear the rifle only to find a very heavy bolt. After a couple of taps, the bolt came free and fell complete out of the rifle! Oh, what a day my friends!

While I’m not completely ruling out an overcharge on my part, I do find it weird that I had a hit at 1200 yards when it happened. I would imagine an overcharge to send my bullet any where but the target. I was using premium brass on its third firing so I didn’t suspect any issues there. After talking to a couple of smiths, they believed the chamfering on the chamber was cut too large which left the case unsupported and lead to case head separation.

Old camber (brass still in chamber) vs new
View attachment 7861699
View attachment 7861701
Click to expand...
PVA barrel?
 
#50
Appreciate you guys posting your mishaps with pictures. I know it's not your proudest moments but it's a good reminder for me (and hopefully others) to pay attention to what I'm doing at the reloading bench and especially what powder I'm using as it's serious business. I once filled some cases with the wrong powder, but was very thankful I did a sanity check when I noticed the wrong powder can on the bench. Same thing, pulled bullets and dumped it. It was H4350 and H1000 so not as big a difference burn rate wise, but still could have been bad as I was putting in 4350 at H1000 charges.

As far as Zermatt, pretty stellar of them to do that for you guys. I am a big fan of their actions, and their CS, although I was really sad to hear about Robbie and will miss her a lot as she was a big part of their stellar CS, and was always so awesome to deal with.

I'm glad you guys are okay, and I agree, Zermatt may have saved your life.
 
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