Colorado Redneck
New member
Post #19 is my nomination for "Post of the Year." And the measuring phenomenon isn't limited to technical discussions.
What is the rule ...."is" there a rule ?
- Thread starter Metal god
- Start date
stinkeypete
New member
When talking about a hobby that involves explosions in your hand or near your face, we need to be precise and accurate in every element of what we do, including communications. Words matter very much.
As a Constructivist (this is an educational philosophy) I believe that people can learn anything far far better when they have an application that they themselves are profoundly interested in. In this case, reloading.
Velocity, weight, time, distance.. these are all pretty easy. Pressure is difficult.
You can read a lot of complex scientific articles online about measuring firearm pressure using very expensive test barrels that put a probe directly on the brass, test barrels that measure using strain gauges around the barrel. You can learn about the time dependent functions of how pressure grows, peaks, and decays, how these vary from test device to test device and the generally accepted fudge factor used to convert from one type of measurement to the other.
The two major agencies you'd want to research are SAAMI and CIP
Since it's your hand and your face close to things that blow up, you might not care to trust anyone else's opinion without a look at the source of the specifications:
https://saami.org/technical-information/ansi-saami-standards/
https://www.cip-bobp.org/en
The first thing to understand is that SAAMI specifications are voluntary. American arms manufacturers can be a member of SAAMI or not, they can comply or not. it's voluntary.
The primary function of SAAMI is to support American arms manufacturers by establishing industrial engineering quality control specifications. Think about Remington cranking out truckloads of 9mm ammunition every day. They can not weigh every charge, they have to rely on modern developments in industrial processes and statistical analysis. There is nothing illegal about Beefalo On Board from making .380 acp self defense ammunition that exceeds SAAMI recommendation, just like lots of us used to hot-load for Ruger single-action hunting handguns.
CIP is an EU thing. It tends to be geared more towards protection of the consumer and it's specifications have the force of law in membership nations. Every time Fiocci starts their factory up to make a new run of shotgun shells, they are required by law to send a sample to CIP who will test that batch and grant (or deny) an approval stamp. (homologation). It's an important distinction.
Let's focus on SAAMI. First of all, every kind of ammunition is not covered under SAAMI and SAAMI takes requests for new ammunition to be included.
The center and rim fire SAAMI specs require a lot of reading and comprehension about statistics. Sorry, thems the facts. It covers all the factors for copper crusher testing and piezo testing and discusses ways to screw up.
When talking about pressure SAAMI members must consider:
Maximum Average Pressure
Standard Deviation
Standard Error
Maximum Probable Lot Mean
Maximum Probable Sample Mean
Maximum Extreme Variation
Sorry, but they are making truckloads of 9mm per day.
SAAMI standards, roughly and imprecisely speaking, tell the average maximum pressure for the factory run, using lots of statistics.
A story to illustrate this might be.. suppose you are loading some 9mm.
SAAMI says the pressure standard is 35,000 psi.
NATO says the pressure standard is 42,000 psi
CIP says 9 Luger, 34,00 measured by piezo and doesn't let CUP be used to measure.
Lets say you personally load some ammo that goes to 36,500 psi in your piezo home test gear. You might decide to pull those bullets and try again.
SAAMI engineers will run 9 more bullets. If the statistics work out and the other 9 are well below 35,00, that one hot bullet might not spoil the lot. "Heck, just an outlier" the guys say. "These things happen when you crank out 10,000 bullets an hour and one 36,500 bullet won't blow up a gun. Probably."
So let's talk about proofing. CIP firearms are all proof tested. Each one. Every gun goes to a CIP proof house where they are forced to eat over pressure 'proof load' ammo. If they survive, they get an official stamp on the barrel. If they fail, their tangled scrap metal is hung on the wall as an example of why they proof test. That bad gun did not go to a consumer.
So they have the proof load pressure and then the ammunition that gun eats regularly, the working pressure is 30% below the proof pressure. The metallurgy of it is that pressure won't stress the barrel while a steady diet of proof loads can lead to metal fatigue and eventual failure.
http://kwk.us/pressures.html
I am no pro at statistics, but I taught the basics a few semesters. This is Industrial Engineering level stats.
What I learned about hand loading, after using my training in physics and math to skate on some very thin ice without falling into cold cold water, is that I generally have no need to go up to the maximum book loads unless I know something very special.
If there is a published maximum for 9mm but I know I have a NATO handgun, I will not sweat shooting 35,000 psi loads. I know that gun is rated for 42,00. But I won't load 42,000 psi loads for it because if I need more power.. I just get a .40 S&W or .44 Magnum or .454 Casull.
Don't break your hammer by trying to swing it too hard.. just get a bigger hammer.
You can call MAP anything you want, but you're wrong unless you're using the SAAMI definition of that term. And wrong can be bad when talking about stuff that goes 'boom' in your hand. MAP means Maximum Average Pressure, it does not mean Absoulute Maximum Pressure.
Remember, as we hand load, there are variations in our powder lots, primer lots, bullet lots, brass lots. Our powder throws and bullet crimps can vary. Each bullet we make might be different from the one a fellow across the country makes with components bought 5 years ago. So....
Stay safe, and why push it when buying a bigger hammer is just plain more fun?
As a Constructivist (this is an educational philosophy) I believe that people can learn anything far far better when they have an application that they themselves are profoundly interested in. In this case, reloading.
Velocity, weight, time, distance.. these are all pretty easy. Pressure is difficult.
You can read a lot of complex scientific articles online about measuring firearm pressure using very expensive test barrels that put a probe directly on the brass, test barrels that measure using strain gauges around the barrel. You can learn about the time dependent functions of how pressure grows, peaks, and decays, how these vary from test device to test device and the generally accepted fudge factor used to convert from one type of measurement to the other.
The two major agencies you'd want to research are SAAMI and CIP
Since it's your hand and your face close to things that blow up, you might not care to trust anyone else's opinion without a look at the source of the specifications:
https://saami.org/technical-information/ansi-saami-standards/
https://www.cip-bobp.org/en
The first thing to understand is that SAAMI specifications are voluntary. American arms manufacturers can be a member of SAAMI or not, they can comply or not. it's voluntary.
The primary function of SAAMI is to support American arms manufacturers by establishing industrial engineering quality control specifications. Think about Remington cranking out truckloads of 9mm ammunition every day. They can not weigh every charge, they have to rely on modern developments in industrial processes and statistical analysis. There is nothing illegal about Beefalo On Board from making .380 acp self defense ammunition that exceeds SAAMI recommendation, just like lots of us used to hot-load for Ruger single-action hunting handguns.
CIP is an EU thing. It tends to be geared more towards protection of the consumer and it's specifications have the force of law in membership nations. Every time Fiocci starts their factory up to make a new run of shotgun shells, they are required by law to send a sample to CIP who will test that batch and grant (or deny) an approval stamp. (homologation). It's an important distinction.
Let's focus on SAAMI. First of all, every kind of ammunition is not covered under SAAMI and SAAMI takes requests for new ammunition to be included.
The center and rim fire SAAMI specs require a lot of reading and comprehension about statistics. Sorry, thems the facts. It covers all the factors for copper crusher testing and piezo testing and discusses ways to screw up.
When talking about pressure SAAMI members must consider:
Maximum Average Pressure
Standard Deviation
Standard Error
Maximum Probable Lot Mean
Maximum Probable Sample Mean
Maximum Extreme Variation
Sorry, but they are making truckloads of 9mm per day.
SAAMI standards, roughly and imprecisely speaking, tell the average maximum pressure for the factory run, using lots of statistics.
A story to illustrate this might be.. suppose you are loading some 9mm.
SAAMI says the pressure standard is 35,000 psi.
NATO says the pressure standard is 42,000 psi
CIP says 9 Luger, 34,00 measured by piezo and doesn't let CUP be used to measure.
Lets say you personally load some ammo that goes to 36,500 psi in your piezo home test gear. You might decide to pull those bullets and try again.
SAAMI engineers will run 9 more bullets. If the statistics work out and the other 9 are well below 35,00, that one hot bullet might not spoil the lot. "Heck, just an outlier" the guys say. "These things happen when you crank out 10,000 bullets an hour and one 36,500 bullet won't blow up a gun. Probably."
So let's talk about proofing. CIP firearms are all proof tested. Each one. Every gun goes to a CIP proof house where they are forced to eat over pressure 'proof load' ammo. If they survive, they get an official stamp on the barrel. If they fail, their tangled scrap metal is hung on the wall as an example of why they proof test. That bad gun did not go to a consumer.
So they have the proof load pressure and then the ammunition that gun eats regularly, the working pressure is 30% below the proof pressure. The metallurgy of it is that pressure won't stress the barrel while a steady diet of proof loads can lead to metal fatigue and eventual failure.
http://kwk.us/pressures.html
I am no pro at statistics, but I taught the basics a few semesters. This is Industrial Engineering level stats.
What I learned about hand loading, after using my training in physics and math to skate on some very thin ice without falling into cold cold water, is that I generally have no need to go up to the maximum book loads unless I know something very special.
If there is a published maximum for 9mm but I know I have a NATO handgun, I will not sweat shooting 35,000 psi loads. I know that gun is rated for 42,00. But I won't load 42,000 psi loads for it because if I need more power.. I just get a .40 S&W or .44 Magnum or .454 Casull.
Don't break your hammer by trying to swing it too hard.. just get a bigger hammer.
You can call MAP anything you want, but you're wrong unless you're using the SAAMI definition of that term. And wrong can be bad when talking about stuff that goes 'boom' in your hand. MAP means Maximum Average Pressure, it does not mean Absoulute Maximum Pressure.
Remember, as we hand load, there are variations in our powder lots, primer lots, bullet lots, brass lots. Our powder throws and bullet crimps can vary. Each bullet we make might be different from the one a fellow across the country makes with components bought 5 years ago. So....
Stay safe, and why push it when buying a bigger hammer is just plain more fun?
stagpanther
New member
Hey! Leave me out of this.
Recycled bullet
New member
A book detailing the politics and decision making process in the laboratory when the ballistics techs are generating load data for the handloading manuals would be a precious document.
Does any one know where I can find such a book?
Does any one know where I can find such a book?