qajaq59
Member
I'll never understand why people want to try and overload a gun. But they have to be people that have never experienced severe pain or a long stay in a hospital. Otherwise they'd NEVER do it.
How many have pushed a load so hard
- Thread starter Nate1778
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Kernel
Member
I’ve never done it myself, but I’ve heard and read of guys buying rifles just to blow them up. It’s called Testing To Destruction. Which sounds a lot more scientific than “buying rifles just to blow them up.”
Hatcher did it after WWII with a collection of the various combatant’s rifles. I seem to recall they were somewhat surprised to find the Japanese Type 99 was far stronger than anyone thought.
For sure, to do it right, you’d want to invest in an old tire (to tie the rifle to) and a looong string (to pull the trigger).
Hatcher did it after WWII with a collection of the various combatant’s rifles. I seem to recall they were somewhat surprised to find the Japanese Type 99 was far stronger than anyone thought.
For sure, to do it right, you’d want to invest in an old tire (to tie the rifle to) and a looong string (to pull the trigger).
hossfly
Member
The extra couple of hundred fps is not going to help much. It's and issue of too much risk for too little reward for me.
True, very true!
Modern rifles are "proof tested" with ammo using a load that is 1.4Xs the max allowed pressure for the cartridge. For a 222 Rem this works out to a proof load of 71,900 psi on a cartridge that working pressure is 50K psi. Rifles are built to any capability as long as it exceeds that needed for the proof test.
Once you exceed the "normal" operating pressure of a cartridge the rate of pressure increase is not linear. One gr of powder in the normal pressure range may raise pressure 1000psi, once the pressures are higher then allowed that same one grain might raise pressure by 5000 psi or maybe only 500. There is no way to tell short of taking your chanches.
There is a reason the books stop at a given pressure level, and it is wise to heed them if we don`t have the equipment to see just what is occuring. Even the "pros" find themselfs wrecking a gun at times if they do it enough. Elmer Kieth is one good example, and I believe Bob Hagle experianced some problems too.
Nate1778
Member
Thanks for the explanation of the "Proof Testing". To clarify I am not going to exceed the max load. I was simply trying to find out how many have Kabooms by venturing into that realm.
USSR
Member
I'd venture to say, more people have done damage to their gun by "underloading", sticking a bullet in the bore, and following up with a plugged bore shot.
Don
Don
One of the problems I find with "Testing to Destruction" is that unless you are only firing each weapon once, it doesn't paint a very good picture. Once you get into elevated material stress levels, each subsequent test is weakening it through crack nucleation.
I'd encourage anyone who wants to do something like this to Wikipedia "fatigue (material)". The subject matter basically deals with cylcling something, usually below yield limit for plastic deformation, until it breaks. Some ferrous metals and titanium have an endurance limit. Under this threshold, you can in theory cycle something forever and it will not break. All other metals including these metals above that limit slowly degrade as tiny cracks in the material form until they ultimately fail. Corrosion also plays a big factor.
Where firearms fall in the limit, I am not sure (above or below the endurance limit), but I have a feeling it is above it. The important thing to note is that the relationship is typically represented on a logarithmic scale. If you look up the Wikipedia article, you'll see a graph for brittle aluminum with the stress levels on the y-axis and the number of cycles on the x-axis. Look at 150 and 300 MPa for example. Say we have a fictious rifle made of this material, and the stress in a rifle were 150 MPa with normal loads, it will survive roughly 10,000 rounds before failure (1 E+4). Now say you double the pressure which should roughly double the stress in the rifle. If we fire 300MPa rounds, the rifle will last about 10 shots (1E+1). Notice doubling the pressure did not half the life of the rifle. Your rifle's life will now be 0.1% of what it would have been. This is just an example, and the actual stress levels would make a difference, if it were more like 100MPa and 200Mpa, you'd have about 1,000,000 and 1,000 respectively. That's still 0.1% of its normal life, but 1,000 isn't so bad. My gut feeling is that an actual firearm's life to critical failure would probably be on the order of E+5 (100,000s) or high E+4s, but that's just a guess.
I'd encourage anyone who wants to do something like this to Wikipedia "fatigue (material)". The subject matter basically deals with cylcling something, usually below yield limit for plastic deformation, until it breaks. Some ferrous metals and titanium have an endurance limit. Under this threshold, you can in theory cycle something forever and it will not break. All other metals including these metals above that limit slowly degrade as tiny cracks in the material form until they ultimately fail. Corrosion also plays a big factor.
Where firearms fall in the limit, I am not sure (above or below the endurance limit), but I have a feeling it is above it. The important thing to note is that the relationship is typically represented on a logarithmic scale. If you look up the Wikipedia article, you'll see a graph for brittle aluminum with the stress levels on the y-axis and the number of cycles on the x-axis. Look at 150 and 300 MPa for example. Say we have a fictious rifle made of this material, and the stress in a rifle were 150 MPa with normal loads, it will survive roughly 10,000 rounds before failure (1 E+4). Now say you double the pressure which should roughly double the stress in the rifle. If we fire 300MPa rounds, the rifle will last about 10 shots (1E+1). Notice doubling the pressure did not half the life of the rifle. Your rifle's life will now be 0.1% of what it would have been. This is just an example, and the actual stress levels would make a difference, if it were more like 100MPa and 200Mpa, you'd have about 1,000,000 and 1,000 respectively. That's still 0.1% of its normal life, but 1,000 isn't so bad. My gut feeling is that an actual firearm's life to critical failure would probably be on the order of E+5 (100,000s) or high E+4s, but that's just a guess.
Squibs and kabooms go together like peanut butter and jelly.
Beyond that I'm not sure how to use knowing how many stupid people have done something fitting to their intellect benefits my knowledge base? I take comfort in my belief that following simple printed load data (cross checked and verified) and staying 10% below max charges does keep a rather large percentage of reloaders safe in their hobby.
Beyond that I'm not sure how to use knowing how many stupid people have done something fitting to their intellect benefits my knowledge base? I take comfort in my belief that following simple printed load data (cross checked and verified) and staying 10% below max charges does keep a rather large percentage of reloaders safe in their hobby.
Nate1778
Member
The knowledge is not so much what stupid people have done in the past. The knowledge of the questions comes in the form of a safety factor. Most items sold to the public are built with a safety factor in mind. Ladders are built to hold twice the weight their rated for, and so on and so forth. My inquiry is how close to that realm are loads and guns built to. Even in a not so stupid moment in any one of our lives our scale goes off kilter and we don't catch it and load a round with .5 more than normal powder than the MAX load of that round, in my for "example" 9mm. Is that gun going to blow up in my hand or is it going to take the shot and let me know I have a hot round and not to shoot anymore. People approach the MAX load like a school boy on the prom queen. I understand that and I do the same when working a load. I was simply approaching how dangerous that realm is, not that my target rounds are going to get there.
A for instance, OSHA requires my trade to be tied off to a anchor that can withstand 5000lbs of force in a 6' fall for a 200 lb man. Its double the force generated in a fall of that height, sometimes triple or quadruple depending on the lanyard in use. If I am a 200lb guy with a 30lb tool belt, will the fall protection fail, no, cause there is a fudge factor figured in there. I am simply seeing if there is a fudge factor in the re-load data.
A for instance, OSHA requires my trade to be tied off to a anchor that can withstand 5000lbs of force in a 6' fall for a 200 lb man. Its double the force generated in a fall of that height, sometimes triple or quadruple depending on the lanyard in use. If I am a 200lb guy with a 30lb tool belt, will the fall protection fail, no, cause there is a fudge factor figured in there. I am simply seeing if there is a fudge factor in the re-load data.
dwave
Member
My reloading is simple:
1. Never exceed max loads.
2. Load for accuracy. Forget the chronograph.
3. Never exceed max loads.
1. Never exceed max loads.
2. Load for accuracy. Forget the chronograph.
3. Never exceed max loads.
ranger335v
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"Hatcher did it after WWII with a collection of the various combatant’s rifles. I seem to recall they were somewhat surprised to find the Japanese Type 99 was far stronger than anyone thought."
The tests were done but it was by P.O. Ackley in his school for new gunsmiths in Colorado. The 99 was the strongest of them all. Ugliest too. Well, there was the Carcano...
The tests were done but it was by P.O. Ackley in his school for new gunsmiths in Colorado. The 99 was the strongest of them all. Ugliest too. Well, there was the Carcano...
dwave
Member
I am sure you are right. Check this out (from Hodgdons website for .357 mag):
158 GR. HDY XTP IMR SR 4756 .357" 1.580" 5.0 896 17,500 PSI 6.5 1146 29,900 PSI
So @ 5 grs pressure is 17,500, but just add 1.5 and the pressure skyrockets to 29,900.
158 GR. HDY XTP Hodgdon H110 .357" 1.580" 15.0 1418 28,600 CUP 16.7 1591 40,700 CUP
Pressure is 28,600 @ 15.0 grs. Pressure rises to 40,700 @ 2.7 more. There is no way you could estimate the pressure rise from just 2 numbers. There are just too many factors.
nate, while your question may express a valid concern, it is also IMHO unanswerable.
Do you know the burst pressure of your handguns' chambers? If so, don't exceed it, presuming you have the means to pressure test all your reloads?
I don't have the info or test gear for mine so I simply stay below max load data which provides me the safety 'fudge factor'.
Might just blindly increasing your loads beyond max present a kaboom? Maybe yes, maybe no. Unless you're feeling really lucky this week, it might pay to simply NEVER exceed the posted max load data? Just a thunk.
You pays yer money and you takes yer chances.
Do you know the burst pressure of your handguns' chambers? If so, don't exceed it, presuming you have the means to pressure test all your reloads?
I don't have the info or test gear for mine so I simply stay below max load data which provides me the safety 'fudge factor'.
Might just blindly increasing your loads beyond max present a kaboom? Maybe yes, maybe no. Unless you're feeling really lucky this week, it might pay to simply NEVER exceed the posted max load data? Just a thunk.
You pays yer money and you takes yer chances.
atblis
Member
The case/primer will fail before the gun does (in most cases).
Rugg_Ed
Member
Now that was interesting reading.
Did see what was left of a guys Model 70, 30-06 after mistakenly scooping the wrong powder into the case. Couple minutes of checking prior to loading would have saved a lot of misery an $$$$$.
Did see what was left of a guys Model 70, 30-06 after mistakenly scooping the wrong powder into the case. Couple minutes of checking prior to loading would have saved a lot of misery an $$$$$.
qajaq59
Member
Does jumping in front of busses come before going past max or after? I always forget....
Nate1778
Member
I would guess to say, that more bus impacts have killed people than Kabooms. No stats to back that up, just taking a wild guess.....
ny32182
Member
I think part of the problem is that the "max" load can vary *considerably* from source to source.
What I end up doing is compiling the data from several sources, and then working from there. Sometimes I settle on a load that is above max according to one source, and below max according to another. Sometimes the "max" load from one manual turns out to be obviously under-pressure in my gun.
I just consider this phenomenon the real reason that loading up from the low end of the published data is the best idea. If all the published data was unquestionably the "holy grail", there would be no need to work up, since we'd automatically know the listed max was totally safe. But by the same token that we don't start at .1 under the listed max, .1 over the listed max may very well be safe, as long as it is work up to, and pressure signs observed... that is my opinion based on my experience.
What I end up doing is compiling the data from several sources, and then working from there. Sometimes I settle on a load that is above max according to one source, and below max according to another. Sometimes the "max" load from one manual turns out to be obviously under-pressure in my gun.
I just consider this phenomenon the real reason that loading up from the low end of the published data is the best idea. If all the published data was unquestionably the "holy grail", there would be no need to work up, since we'd automatically know the listed max was totally safe. But by the same token that we don't start at .1 under the listed max, .1 over the listed max may very well be safe, as long as it is work up to, and pressure signs observed... that is my opinion based on my experience.
Working up loads.
My experience with these calibers and working up loads has been one component change can make a significant difference. Just going to a magnum primer makes a significant difference. Reduce the variables to as few as possible.
Once you are familiar with the components, and use the same components consistently, varying load then gives you results you can see with the naked eye. Or feel!
I've had some extreme experiences with loads that were in the middle range of the powder recommendations. Thankfuilly, flattened primers, keyholing, shredded jackets, and stuck cases, were my only result.
My experience with these calibers and working up loads has been one component change can make a significant difference. Just going to a magnum primer makes a significant difference. Reduce the variables to as few as possible.
Once you are familiar with the components, and use the same components consistently, varying load then gives you results you can see with the naked eye. Or feel!
I've had some extreme experiences with loads that were in the middle range of the powder recommendations. Thankfuilly, flattened primers, keyholing, shredded jackets, and stuck cases, were my only result.
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