Hm - overpressure

[noslerpartition]

My Ex-wife told me yesterday that she tore off her extractor with ammo I loaded years ago (we were still together back then, so no intension! Wouldn't do that at all, because I think even split up, the boys need both parents...).
The loads were not on the upper end and I have no idea what happened
They are maybe 10 years old and worked just fine back then. Does powder age that quickly??
I had some surplus and they did the se to my girlfriend's rifle - I dump them. A friend shot one of them , too. Very hard bolt-lift and he shot only one.

What's your experience: when do loads start to age and become unpredictable?
I have some 10 years old and start wondering if I should pull the bullets...

 

[salmonchaser]

I wouldn't expect 10 year old ammo to be a problem just due to age. I'm curious what others may have experienced.

 

[ShadeTree]

Not saying it's impossible for powder to go bad inside a case, but highly unlikely. And if by chance it would go bad the results besides not working at all would be inconsistency/inaccuracy, delayed ignition, incomplete burn, slower velocities. etc. None of which would result in high pressure. I cannot say unequivocally that in the unlikely event that powder went bad inside a case, it cannot make high pressure, but I just don't see how.

Lots of variables that could cause it that without the rifle and ammo being in your possession would be impossible to know for sure. One thing that can happen is that the bullet can become galded or welded to the case neck. That absolutely will result in high pressure. The other thing is the rifle itself. Things like corrosion or even relatively heavy surface rust inside the chamber, particularly in the neck area would drive up pressures immensely.

I had a buddy bring me a 760 that would not fire. Turns out it's very good it wouldn't. What was happening is the action was closing, but not locking completely, and on a 760 if that action lock is not engaged the trigger mechanism is not cocked. Inspection revealed fairly heavy surface rust inside the chamber and neck. He had stored it for a couple months inside a hard gun case and it condensated in there. Cleaned it up and all was/is fine now. Had he been able to fully close the action, guaranteed high pressure would've been the result.

 

[hunter24605]

I was just going to say what ShadeTree beat me to. Cold-welding of the bullet to the neck, in ammo that's been sitting for years, is a possible cause. I've heard people say that when they have old ammo, and cold-welding is a concern, they'll seat them a tiny bit deeper to break the weld before shooting. But I wouldn't think, unless they were top end loads, it would cause that high of a pressure spike, there would be warnings all over factory ammo, if so. Also I would consider that it was just time for a weakened extractor to fail, or chamber issues like excess lube, carbon ring, etc that can generate high pressure.

 

[noslerpartition]

No idea if she ever cleaned the rifle in the past 5 1/2 years since I moved out.
Probably not.
But I am 100% sure the loads were nowhere near max. They were for shooting cinimar and running boar, which doesn't require peak loads or accuracy.
Still makes you wonder if something like that happens

 

[RL338]

I had some surplus and they did the se to my girlfriend's rifle - I dump them.

When you pulled these were they cold welded?
A little history on your load might provide some help.
Make and model of rifle. Brass , bullet , powder selection. Brass prep. Ammo storage (cool dry or warm damp).
My dad still has factory ammo for his rifle from the late 60’ and early 70’s that show no issues.

 

[noslerpartition]

Well.
I loaded them mid range.
For the last 5 1/2 years, I don't know how they were stored.
Guess in a cellar.
I hope to get some to learn from it, but don't have any now.
I used data from the powder company, QL and whatever data I could get.
So after 15 years of reloading, I am safe as can be they were safe
Even checked inside volume, though far from max.
Enough space from the lands.
I am simply confused what happened.
For such loads, I go to the lower to mid load suggestions.
But somehow it came out bad...

 

[wvbuckbuster]

A lot of old surplus ammo gets shot all the time. Buddy of mine has cans of 30-06 ball he runs thru his M1 and 03 without any problems. As others have said hard to tell without having rifle in hand plus the loads. If you do get some of the loads and the load data is with them dissect one and weight the powder charge just to double check. Just a thought. Dan.

 

[noslerpartition]

My 30-06 surplus is still rather mild.
The 308 gets trashed. Very hard bolt lift In a Remi 700, tore off the extractor from the Bergara.
No way they will be shot again.
But with my haldloads?! No idea what happened

 

[TXbaldhunter]

I keep very little loaded ammo on hand.I do have some factory stuff,but I'd rather load up fresh stuff for hunting rather than use something that has been sitting for a good length of time and find out there may be accuracy or pressure issues with it.I have seen powder go bad inside the loaded case on ammo that was perfectly good just a few months before.It's rare that happens,but it can.I had some Accurate 4064 that I loaded for my 308 Win.I was getting excellent accuracy with it.A couple of months later there was a recall on the powder.I had the powder for almost two years,so I contacted the company and they told me to immediately destroy the powder and break down any ammo loaded with the powder.I was paid back for all the powder I had on hand.About a month later I found three loaded rounds that I missed while I was at the range.Since it was fine just a few months back,I decided to just go ahead and shoot them.I fired the first round and the bolt on rifle was very tight to open.It smeared the headstamp on the brass from the high pressure when I opened it.I got home and broke down the other two cartridges.The powder was damp,clumpy and corrosive.Another issue with old ammo is cold weld.This can really become a greater issue if your loaded at max load.A little extra resistance from the cold weld can put you over max.When loading,I like clean cases.I wipe the inside of the case neck with a clean cotton bore mop with a lite coat of powdered graphite,to help dry lube to aid bullet seating.Using this method,I haven't had any cold weld issues.
Here is a picture from the two cartridges I broke down that had the bad powder.Look at how the powder was stuck to the base of the bullet and you can also see the corrosion developing as well.

 

[ShadeTree]

Wow. So it didn't go bad as in stale or ineffective, it went bad as in broke down in some kind of chemical reaction? Amazing. Never seen it.

 

[wvbuckbuster]

I keep very little loaded ammo on hand.I do have some factory stuff,but I'd rather load up fresh stuff for hunting rather than use something that has been sitting for a good length of time and find out there may be accuracy or pressure issues with it.I have seen powder go bad inside the loaded case on ammo that was perfectly good just a few months before.It's rare that happens,but it can.I had some Accurate 4064 that I loaded for my 308 Win.I was getting excellent accuracy with it.A couple of months later there was a recall on the powder.I had the powder for almost two years,so I contacted the company and they told me to immediately destroy the powder and break down any ammo loaded with the powder.I was paid back for all the powder I had on hand.About a month later I found three loaded rounds that I missed while I was at the range.Since it was fine just a few months back,I decided to just go ahead and shoot them.I fired the first round and the bolt on rifle was very tight to open.It smeared the headstamp on the brass from the high pressure when I opened it.I got home and broke down the other two cartridges.The powder was damp,clumpy and corrosive.Another issue with old ammo is cold weld.This can really become a greater issue if your loaded at max load.A little extra resistance from the cold weld can put you over max.When loading,I like clean cases.I wipe the inside of the case neck with a clean cotton bore mop with a lite coat of powdered graphite,to help dry lube to aid bullet seating.Using this method,I haven't had any cold weld issues.
Here is a picture from the two cartridges I broke down that had the bad powder.Look at how the powder was stuck to the base of the bullet and you can also see the corrosion developing as well.

That's the first time I've seen powder do this. Thanks for sharing, Dan.