Look at the primer? Where are you going to find it?
Model 70 explosion
- Thread starter Buckmastr
- Start date
Look at the primer? Where are you going to find it?
There was a catastrophic case failure. Look at the breech of the barrel, and the remains of the cartridge case.
Inspection of the barrel would reveal if there were an obstruction.
Given that this was a rifle that had been used previously, it is very unlikely that there was a heat treating issue.
Inspection of the barrel would reveal if there were an obstruction.
Given that this was a rifle that had been used previously, it is very unlikely that there was a heat treating issue.
Wheres Ganderite when you need him? He's got some expertise in blowing up rifles, I'd love to see his opinion.
Would also be cool to get to the bottom of this but I suspect we'll never know exactly what happened...
Is that part of the brass obstructing the bore in picture 2?
Would also be cool to get to the bottom of this but I suspect we'll never know exactly what happened...
Is that part of the brass obstructing the bore in picture 2?
- Location
- Western Manitoba
By zooming in on that picture, I think I see some lettering beside the extractor cut - so part of the case rim?? That would mean looking at about half of a primer pocket that has opened to sort of .300 or larger before half or more dissolved or departed - so perhaps what appears to be inside the chamber is a blown open flash hole? Again - blown wide with at least half dissolved or departed? Not clear, but would think if so much of the gases came rearward in this event, almost suspect that bullet to be partway up the barrel?? So would be looking for two things in the barrel - this round's projectile - maybe part of the first round's projectile?? USA has got millions of lawyers and super good analysts - hopefully competent people get to inspect, evaluate and report on what is in there??
If you refer to the photos of rifles deliberately destroyed in PO Ackley's book, a catastrophic case failure and a broken receiver ring go hand in hand with this sort of rifle.
I had occasion to examine a push feed Model 70 in 7mmRM which had been fired with a .308 cartridge. The receiver stayed in one piece; the stock blew out at the magazine. The bullet exited the barrel. Obviously the .308 case is smaller in diameter than the 7mmRM, and the case ruptured. While the rifle was wrecked, the shooter was not hurt.
I had occasion to examine a push feed Model 70 in 7mmRM which had been fired with a .308 cartridge. The receiver stayed in one piece; the stock blew out at the magazine. The bullet exited the barrel. Obviously the .308 case is smaller in diameter than the 7mmRM, and the case ruptured. While the rifle was wrecked, the shooter was not hurt.
It is so easy to leave a small bit of pistol powder in the bottom of a powder measure if you are finished and get called away on some emergency or drop the last little bit in the wrong can which is the first load out the next time you use that can. Good practices usually keep that from happening but even the most careful of us can make a mistake. I have seen a few such screw ups in the 60 years I have been loading and by reloaders who are very careful. It may not be one of those 2 things but it sure looks that way to me.
Picture 3 shows the gas port hole still there so that's what has me thinking it failed (cracked) on the right and wrapped around to the left.
Almost looks like the receiver ring is all still there although flattened.
Lots of brass flowed into the extractor cut area (right side) of barrel.
- Location
- Western Manitoba
First picture has the top of the receiver with a Beuhler style base, just below the turrets on what is left of the scope. So the top 60 or more degrees of the receiver went up - left side with the pressure vent hole went left - and so on.
Wow, quite the RUD (rapid unplanned disassembly).
Thankfully the shooter or others were not more seriously hurt, hopefully he can get past the injuries.
Seeing none of us have enough info to do anything more than speculate I’ll play.
I’m not on Campfire so I’m limited to the info on here...
-Did the gun ka-boom to overpressure? Yup. Real bad...
-was it from that factory ammo, possible but unlikely in and of itself, more likely contributing to it (right or wrong it was the fuel). Pulling factory ammo from the same batch would confirm if the factory screwed up but without a bunch of other events happening it is fairly unlikely it was a factory ammo issue.
If it was from factory ammo it was either loaded with a fast pistol powder(unlikely) or more likely, loaded too light with a powder which has detrimental effects if experiencing a flash over - which could cause/explain a massive pressure increase.
-If the barrel was obstructed it had to be directly at the action or it would have ballooned and/or split.
-The shell pictured with the dint also looks to have impact damage on the projectile suggesting the damage was done during the ka-boom, not poor reloading practices.
-The receiver shows where the locking lug punched through the receiver suggesting the bolt was in lock-up.
the pressure was enough to drive the bolt through the receiver and pluck the front band off, turning the scope into multiple pieces and the stock into shrapnel...yet not expand, split or bloat the barrel.
-the second shell could have caught on the feed ramp and pushed into the case reducing capacity, or if the first bullet was still in the throat and he racked it hard that could burry the second bullet in the case but he would have had a squib on round 1...
So my guesses:
Optimism in the shooters favour:
-something at the factory kept that case from getting a full charge of powder and it flashed over.
Or, sceptical of the info:
-A poor reload was used.
wrong powder in reload, wrong weight of bullet/powder, wrong bullet diameter, etc.. and/or
-a bullet still in the barrel throat maybe that first round was a squib and nothing actually left the barrel.
Either way he’s getting his 15 minutes of fame for all the wrong reasons. Ouch.
Thankfully the shooter or others were not more seriously hurt, hopefully he can get past the injuries.
Seeing none of us have enough info to do anything more than speculate I’ll play.
I’m not on Campfire so I’m limited to the info on here...
-Did the gun ka-boom to overpressure? Yup. Real bad...
-was it from that factory ammo, possible but unlikely in and of itself, more likely contributing to it (right or wrong it was the fuel). Pulling factory ammo from the same batch would confirm if the factory screwed up but without a bunch of other events happening it is fairly unlikely it was a factory ammo issue.
If it was from factory ammo it was either loaded with a fast pistol powder(unlikely) or more likely, loaded too light with a powder which has detrimental effects if experiencing a flash over - which could cause/explain a massive pressure increase.
-If the barrel was obstructed it had to be directly at the action or it would have ballooned and/or split.
-The shell pictured with the dint also looks to have impact damage on the projectile suggesting the damage was done during the ka-boom, not poor reloading practices.
-The receiver shows where the locking lug punched through the receiver suggesting the bolt was in lock-up.
the pressure was enough to drive the bolt through the receiver and pluck the front band off, turning the scope into multiple pieces and the stock into shrapnel...yet not expand, split or bloat the barrel.
-the second shell could have caught on the feed ramp and pushed into the case reducing capacity, or if the first bullet was still in the throat and he racked it hard that could burry the second bullet in the case but he would have had a squib on round 1...
So my guesses:
Optimism in the shooters favour:
-something at the factory kept that case from getting a full charge of powder and it flashed over.
Or, sceptical of the info:
-A poor reload was used.
wrong powder in reload, wrong weight of bullet/powder, wrong bullet diameter, etc.. and/or
-a bullet still in the barrel throat maybe that first round was a squib and nothing actually left the barrel.
Either way he’s getting his 15 minutes of fame for all the wrong reasons. Ouch.
Why? Manufacturers' make mistakes as well. I worked at a gun store years ago when the pressure to manufacture as quickly as possible wasn't as high as it is now and we returned ammo to the factory often. Either there would be a recall or the customer discovered a problem and the factory replaced it. Most common problem was improperly seated bullets. But there were examples of pistol powder in rifle cartridges.
Strange and please correct me if I'm wrong here but gas vent on a Model 70 should be on the right only.
I see where there is a chunk of receiver ring still attached to the mount. Good catch.
At work right now so I can't open up the safe and check a pre-64 or a new CRF action.
I see where there is a chunk of receiver ring still attached to the mount. Good catch.
At work right now so I can't open up the safe and check a pre-64 or a new CRF action.
Why didn't the first round have issues though? Seems unlikely that one round would be fine, but the next would do THAT with factory ammo, considering the whole box would be coming off the same production line?
