Determining H110/296 Max Loads

[mikeg1005]

For my specific examples this is for 357mag in a 6" GP100.

I have heard on a many occasions that H110/296 is a powder that has a pretty steady, linear pressure curve basically all the way up 100% case capacity. My main full power magnum load is a Lee 358-158-RF (drops around 160-161ish) mixed brass, and 16.5gr of H110. I based this off a load I found in the Lyman's 49th for a 160gr lead. Runs great, even with Winchester brass which has a lower volume (see pic below of federal (R) Win (L) brass cut to the loading point of a 158gr XTP with a 16.7gr charge)

http://castboolits.gunloads.com/attachment.php?attachmentid=114234&d=1408719796&thumb=1 (http://castboolits.gunloads.com/attachment.php?attachmentid=114234&d=1408719796)

I read a few times that people said you can determine a specific max load for a given bullet/case by determining the weight of a powder charge that gives you 100% case capacity with your case/bullet combo for H110/296.

Since from published load data shows that almost an identical charge can be used for a 158gr jacket and a 160gr lead bullet in 357mag with H110, has anyone tried/see an issue with increasing the charge in the federal case to get closer to 100% fill capacity?

I recently purchased 1000 pcs of starline brass which has a very similar volume to federal, and I'd like to work up a max load specific to that brass/my current bullet I use.

I also did another test with a 125gr XTP which by the book is compressed at max, picture below compared to the 158gr (both in federal brass per Lyman 49th)

http://castboolits.gunloads.com/attachment.php?attachmentid=114235&d=1408719922



Thanks in advance.

[243winxb]

brass cut to the loading point of a 158gr XTP with a 16.7gr charge)
Different. :veryconfu

[mikeg1005]

Correct, but I was doing it to see how much volume is left in a case for a given published load. The 158gr and 125gr XTPs were the only bullets I had on hand that were specifically mentioned in load data. Seeing if there was truth to the concept of "fill the case to 100% capacity" that I have heard people say... judging by the fact that a Winchester (lower volume case) is almost full with said load (nothing says not to use WIN cases with load data) I'm thinking there might be some merit to what people are saying.

[DeanWinchester]

It would be nice if this formula were fact. I'm about to start loading a 200g RCBS 35-200 in a single shot 357 magnum. Data isn't exactly easy to find. I imagine the velocities produced would be impressive because my seating depth for the 200g is gonna about what your 125g is.

[silverado]

This is very interesting. I also have a 6 inch gp100 and 4 pounds of w296 I have not touched yet... I will be following closely. I am very cautious in the "black arts" of doing anything outside of published loads. I will be watching this thread very closely. I am guessing that "max loads" determined this way are extremely compressed?

[mikeg1005]

Just to be clear (since I know there are a lot of published data NAZIS out there). Yes I am kind of pushing the envelope here but I am determining where the 'tested' max limits of it are since there is a TON of discrepancies with H110/296 load data, especially 'max loads'. By this I mean starting points are all over the page, and max charges for bullets of almost identical weight/dimensions vary by as much as 1gr.... and I also found an interesting trend that max charges for jacketed bullets and lead bullets with this powder are very close to being the same.

There is also the mixed brass thing... if you look at the 2nd picture above, case on the left, you'll see that is a federal case with the book load for a 125gr XTP (case cut to bottom of bullet at published OAL). The same load in say a Winchester case would be overflowing... but yet people shoot the published loads without concern for headstamps they are using.

[mikeg1005]

I am guessing that "max loads" determined this way are extremely compressed?

I don't think so, besides ball powders like H110/296 are pretty dense/concentrated so they will not compress much. Pictures above are the Hodgdon/Lyman 49th max loads with a 158gr XTP and 125gr XTP. The 158 isn't compressed at all, the 125gr would be... it would make sense that you can compress a light bullet load since pressure spike isn't as likely as it is with a heavier bullet.

[mikeg1005]

It would be nice if this formula were fact. I'm about to start loading a 200g RCBS 35-200 in a single shot 357 magnum. Data isn't exactly easy to find. I imagine the velocities produced would be impressive because my seating depth for the 200g is gonna about what your 125g is.

That's approaching 357Max isn't it? I'm guessing you are loading the 200s out really long. Book makes for 125gr is like 22ish gr of powder.

[mikeg1005]

I just did a little googling... supposedly the old manuals Lyman's 46th listed a max load of 18gr of a lead 158gr and Win 296.

Can anyone confirm?

[dtknowles]

You sort of asked how are people getting away with loading to a bit over max published data. History says that if you run hot .357 loads in some revolvers they get loose. That can even go for current max published data. I don't think a few slightly over max loads will Kaboom a revolver like a double charge or bore obstruction might. A loose revolver might fire out of time and cause a bigger problem. I don't have any experience with GP 100 and I only have a few hundred max loads thru my Dan Wesson Model 15. I have seen no problems with max loads and I use Win brass and magnum primers, 158 gr. cast and jacketed.

Tim

[44man]

That is too much, don't compress. 100% will be at the bottom of a seated boolit. I would go with book max loads.

[mikeg1005]

That is too much, don't compress. 100% will be at the bottom of a seated boolit. I would go with book max loads.

That's what I figured, I couldn't imagine sticking another 1.5+grs into the case above. The 100%/max load concept, have you heard of that before 44man? Trying to see if there is any merit to it.

[W.R.Buchanan]

Mike: My first question is why would you want to do this? There are literally reams of data available for loading this powder.

Even if you went with the highest load published you are still going to be safe. Kind of the idea? IE: Be safe.

What one has to ask is,,, "What you are going to gain by pushing this particular envelope?" Especially in a short barreled Revolver like a GP100? Which I think is what you are shooting? If not,,, correct,,, however which gun isn't going to make any difference because the amount of velocity gained in any revolver is not going to yield any significant increase in any useable performance.

In the end there must be a purpose for the extra performance you seek.

Point being,,, the easiest and safest way to get what you appear to be looking for,,, is to get a .357 rifle. In which case any published book load will be more than adequate.

My biggest warning here is that once you have exceeded published data,,, unless you have access to pressure testing equipment,,, you are entering dangerous territory with a blindfold on.

With no real use for the extra performance, you are just taking very unnecessary risk for no reason.

Does this still sound like a good idea to you?

Hiel Hitler!

Just my .02 on this subject.

In this case maybe a sound bite from the voice of reason.

Randy

[fecmech]

Since from published load data shows that almost an identical charge can be used for a 158gr jacket and a 160gr lead bullet in 357mag with H110, has anyone tried/see an issue with increasing the charge in the federal case to get closer to 100% fill capacity?

I would bet a good amount of money that you could do it and do it a number of times with no kabooms. Why you would want to is beyond me. What is magical about 100% fill? I'm not being a "smart a**" actually curious as to why you want to do it.

[osteodoc08]

How do I determine max 296 load......I look in the manual and work my way up from the bottom and look for pressure signs to the published max.

That would be my recommendation to anyone that asks.

[mikeg1005]

Mike: My first question is why would you want to do this? There are literally reams of data available for loading this powder.

Even if you went with the highest load published you are still going to be safe. Kind of the idea? IE: Be safe.

What one has to ask is,,, "What you are going to gain by pushing this particular envelope?" Especially in a short barreled Revolver like a GP100? Which I think is what you are shooting? If not,,, correct,,, however which gun isn't going to make any difference because the amount of velocity gained in any revolver is not going to yield any significant increase in any useable performance.

In the end there must be a purpose for the extra performance you seek.

Point being,,, the easiest and safest way to get what you appear to be looking for,,, is to get a .357 rifle. In which case any published book load will be more than adequate.

My biggest warning here is that once you have exceeded published data,,, unless you have access to pressure testing equipment,,, you are entering dangerous territory with a blindfold on.

With no real use for the extra performance, you are just taking very unnecessary risk for no reason.

Does this still sound like a good idea to you?

Hiel Hitler!

Just my .02 on this subject.

In this case maybe a sound bite from the voice of reason.

Randy

I completely agree with what you are saying... and my current 16.5gr load shoots well (logic says to stick with it then). I'm more so asking just to get some general knowledge on the topic since there is a lot of contradicting data out there, and not as much because I want to do it (the starline brass was an example that I thought of)... idea kind of got sparked when talking to the guys I shoot USPSA with, who run open division guns that are pushing 115-125gr bullets at over 1500fps out of their 9mm major guns which are way, way, above SAAMI 9mm specs but utilize a regular 1911 9mm barrel. Curious what 357mag could do if one went above the specs but still within a safe range in terms of the strength of the pistol

Like mentioned really no point in putting extra straight on the revolver for pretty much no terminal ballistic benefits.... my purpose is just to see what is actually possible and still within what is/was at one point in time considered a safe pressure range... I've got other pistols/rifles that have more power if needed so this isn't at attempted to hotrod the 357mag because I don't have other options.

[mikeg1005]

How do I determine max 296 load......I look in the manual and work my way up from the bottom and look for pressure signs to the published max. .

Which published max? That's kind of what I'm getting at, just had a friend with an old manual confirm the 18gr with a 158gr LRN, highest I have seen today is 16.5gr... and even others say do not exceed the mid 15s.

[mikeg1005]

What is magical about 100% fill? I'm not being a "smart a**" actually curious as to why you want to do it.

I'm trying to figure that out as well... because I have seen/heard it on multiple occasion... and its very obvious that H110/296 give you the best ES/SD when loaded hot... not sure if its just a "alright we'll stop here" type thing... or if there is actually some kind of factual data behind it.

[44man]

That's what I figured, I couldn't imagine sticking another 1.5+grs into the case above. The 100%/max load concept, have you heard of that before 44man? Trying to see if there is any merit to it.
Yes, 90% to 100%. Never seen 296 spike but I would not compress it. It is only to touch a boolit base seated proper.
Load to find accuracy only anyway. Never found top loads shoot good. you will see groups tighten, then open, back to the best groups. To seat shallow to add more powder is not sane. You have no tension and the primer can push the boolit way into the bore before ignition. 100% does not mean a case full, leave it alone.

[osteodoc08]

Which published max? That's kind of what I'm getting at, just had a friend with an old manual confirm the 18gr with a 158gr LRN, highest I have seen today is 16.5gr... and even others say do not exceed the mid 15s.


The highest published maximum your comfortable with so long as there is no signs of high pressure.

You must take into consideration the OAL as well as the weight and material of the projectile. Generally speaking, lead boolits will require more powder to equal the pressure of a jacketed bullet.

Start with a known published minimum and work up until you see signs of high pressure (and back off) or reach a published max youre comfortable with (and not seeing signs of high pressure).

You also need to look at what youre trying to accomplish. If hunting with anything 41cal and up, most game can be taken with much less than published max loads. If trying to wring out the most velocity....what are you actually gaining. Any pistol bullet or boolit has the BC of a flying brick chit house. If you're doing it "just cause you can". more power to you, but take it slow and be careful.

[Whitespider]

I have heard on a many occasions that H110/296 is a powder that has a pretty steady, linear pressure curve basically all the way up 100% case capacity.
I read a few times that people said you can determine a specific max load for a given bullet/case by determining the weight of a powder charge that gives you 100% case capacity with your case/bullet combo for H110/296.

I just gotta' ask...
Where, exactly, have you heard and read these things??
How, exactly, are you determining what your pressures are running??

I believe you're missing something... only hearing and reading the portion you want to hear and read.
I agree that pressures (using velocity as a gauge in my testing) stay relatively linear as the charge of H110/W296 is increased up to 100% case capacity, but only as long as pressures stay within the design limits of the propellant. Meaning, if the cartridge is large enough to allow an overcharge, pressures will become erratic and dangerous (think of loading a .45-70 to 100% capacity with H110/W296). Some cartridges will allow loading 100% case capacity with H110/W296 without danger of an overload (the .22 Hornet comes to mind)... many will not‼ The "steady, linear pressure curve up to 100% capacity" is referring to what happens when H110/W296 is used in a compressed load... the linearity can, and often will, go out the window... it ain't sayin' you can just willy-nilly load it to 100% capacity in any cartridge.

You're justifying your (so-called) testing by using information perceived in error... perceived in error by you.
*

[44man]

I just gotta' ask...
Where, exactly, have you heard and read these things??
How, exactly, are you determining what your pressures are running??

I believe you're missing something... only hearing and reading the portion you want to hear and read.
I agree that pressures (using velocity as a gauge in my testing) stay relatively linear as the charge of H110/W296 is increased up to 100% case capacity, but only as long as pressures stay within the design limits of the propellant. Meaning, if the cartridge is large enough to allow an overcharge, pressures will become erratic and dangerous (think of loading a .45-70 to 100% capacity with H110/W296). Some cartridges will allow loading 100% case capacity with H110/W296 without danger of an overload (the .22 Hornet comes to mind)... many will not‼ The "steady, linear pressure curve up to 100% capacity" is referring to what happens when H110/W296 is used in a compressed load... the linearity can, and often will, go out the window... it ain't sayin' you can just willy-nilly load it to 100% capacity in any cartridge.

You're justifying your (so-called) testing by using information perceived in error... perceived in error by you.
*
We need to stay with the .357 mentioned, No way to put 296 in large cases. But the loads shown in the .357 have already gone wild and for what purpose?

[DeanWinchester]

Trail Boss is the only powder I've ever known that can be loaded to 100% in pretty much any case....safely.

[mikeg1005]

I just gotta' ask...
Where, exactly, have you heard and read these things??
How, exactly, are you determining what your pressures are running??

I believe you're missing something... only hearing and reading the portion you want to hear and read.
I agree that pressures (using velocity as a gauge in my testing) stay relatively linear as the charge of H110/W296 is increased up to 100% case capacity, but only as long as pressures stay within the design limits of the propellant. Meaning, if the cartridge is large enough to allow an overcharge, pressures will become erratic and dangerous (think of loading a .45-70 to 100% capacity with H110/W296). Some cartridges will allow loading 100% case capacity with H110/W296 without danger of an overload (the .22 Hornet comes to mind)... many will not‼ The "steady, linear pressure curve up to 100% capacity" is referring to what happens when H110/W296 is used in a compressed load... the linearity can, and often will, go out the window... it ain't sayin' you can just willy-nilly load it to 100% capacity in any cartridge.

You're justifying your (so-called) testing by using information perceived in error... perceived in error by you.
*

That's comparing apples to oranges, there is no useful load data for 45-70 with H110... my point was for calibers that that powder is designed for.

I have heard/seen this on forums when doing research for load data over the years. Both in 357mag and 45 Colt, I would imagine its the same for 41 and 44. I brought it up here to discuss if there is merit behind the concept, sounds like it is based on what 44man is saying.

[leadman]

Some time back the max pressure was lowered in the 357 magnum because of the guns shooting loose. When I am investigating loads for a cartridge I consult the current manuals and go to the powder manufacturers website. The website should have the most current data as this is the easiest place for the powder companies to correct any bad data. You can also give the powder company a call and speak with a technician or ballistician.
I have been reloading for 40 years and never heard of the 100% method other than for black powder.

[W.R.Buchanan]

Mike: There is such a thing as "going to the source" when obtaining any data. That way you are getting the strait skinny and not some Bozo's interpretation of said data.

People lots of times don't understand what they read. And when they relate it to someone else it may get mutated further. The fact that they try to get said data to work in their heads is so that they can sound like they understand what is going on, and in fact they do understand what they think they know. However that understanding seldom is correct. This leads to false data being spread around the area.

If everyone goes to the same source and reads and then understands the same information unilaterally, then everyone comes away with the same understanding. This is the correct way to transmit data.

One other point I'd like to make and this one may seem odd to some but pressure is not the only force acting on the rear of a boolit.

Just like a piston in an engine absorbs heat energy and translates it to linier motion so does a boolit. In other words if pressure was the only force acting on a boolit then velocity would be a linier relationship to pressure.

We know this is not true since various powders in various amounts will propel the same boolit the same speed at various pressures. That has to do with the Pressure Burn Ratio of the powder cartridge/ load combination.

Since I only have a cursory understanding of this concept I will not venture further into it, however it is one of the major factors governing what kind of powder works best in a given cartridge case.

However one thing I can say for certain is that past a certain amount of powder there is not enough time for all of the powder to burn in a short barrel. Therefore some of the powder charge is simply blown out of the barrel and is wasted.
This is the way that they determined the max charge in a black powder rifle. They would shoot over clean snow and increase the charge until they got a bunch of unburned powder blown out onto the snow.

This would be the case in your 6" bbl.

With your .357 max load of W296/H110 will deliver X velocity from your GP100 6" You will get from 200-400fps more from a 20" rifle barrel with the same exact load. The reason is that all of the powder has a chance to burn and contribute to the pressure curve that is accelerating the boolit. As opposed to being wasted by blowing out the barrel unburned.

Obviously the maximum load for any given firearm is the one that burns all of the powder just before it exceeds the firearms ability to contain the pressure. However the term Maximum Load is misleading. It should be "Maximum Safe Load," since a maximum safe load will contain a certain percentage of safety margin built in to deal with unforeseen variables, and to keep everybody out of trouble. Morons included.

Unfortunately there is no IQ test before you can reload, so there must be an appropriate safety margin built into any published data.

Randy

[jonp]

That's what I figured, I couldn't imagine sticking another 1.5+grs into the case above. The 100%/max load concept, have you heard of that before 44man? Trying to see if there is any merit to it.

I put a similar question to Hodgen once about max using H110 in both my 6in GP100 and a Blackhawk. The Manu was pretty clear on not compressing this powder.

[dtknowles]

.............Just like a piston in an engine absorbs heat energy and translates it to linier motion so does a boolit. In other words if pressure was the only force acting on a boolit then velocity would be a linier relationship to pressure.

We know this is not true since various powders in various amounts will propel the same boolit the same speed at various pressures. That has to do with the Pressure Burn Ratio of the powder cartridge/ load combination.

Since I only have a cursory understanding of this concept I will not venture further into it, ...............

Randy

Heat absorbed by the piston does not make it move faster, heat transfer to the piston takes heat out of the combustions gases reducing their pressure.

Force equals mass time acceleration, true all the time. A free body diagram would show a force on the rear of the bullet equal to the pressure times the bore/groove area and a friction force acting in the opposite direction (caused by a few things) Heat transfer to the bullet is of little effect even if it was much larger than the little that happens in such a short time and it does not make the bullet go faster.

The reason that different powders can produce the same velocity with different PEAK pressures is because the pressure is not constant but rises and falls as the bullet travels down the barrel and the velocity is better predicted by the area under the pressure/time curve than the peak pressure.

Tim

[tazman]

I understood what you just said because I had a college education in physics and chemistry. I would bet that it went right over a lot of people who reload though. Many simply do not have the background or vocabulary for that.
If you could find a simpler/plainer way of stating what you just said, I think it would be better.

[W.R.Buchanan]

Tim: I used the heat extraction example to show there are other forces working.

The heat extraction of and internal combustion engine is a concept that not many can understand because really it makes little sense. However it is fact.

The heat being extracted from the combustion cycle increases the electron activity on the top of the piston and it does influence motion of the piston. Most all of those electrons are being expelled from the top surface of the piston being bounced off the top of the combustion chamber and back off the top of the piston. This is the primary force at work. The pressure generated is secondary and would not exist without the electron movement.

Another example of this phenomenon is in a steam turbine. in a closed Steam Turbine System or in the case of high efficiency turbines operating at nearly 4000 psi the pressure drops continuously from the exit of the boiler feed pump to the condenser. The pump must put out more pressure than the boiler is generating or it couldn't push the water in. However the heat (1000F) is also extracted after the Super Heater by way of the High Pressure Turbine. Then the steam is sent back to the boiler to be reheated in the Re-Heater back to the 1000F and then that heat is extracted by the Intermediate Pressure Turbine. The pressure is decaying ALL the WAY thru this cycle as the Steam does not increase in pressure when being reheated, it is far past the point of expansion in this Temp/Pressure regime and dropping either the press or temp will not cause the material to condense. In Fact it is not called "Steam," it is called "Stuff."

The final heat extraction occurs in the low pressure turbine which by the last stage is operating in a Vacuum. The steam temp at that point is below 190 degrees and the vacuum insures that the steam is condensed into water, and then recycled thru feed water heaters and more pumps regaining temperature and pressure until it reaches about 700 degrees before the boiler feed pump which finishes pumping it up to 4000+ psi to be introduced into the boiler where it picks up another 300 degrees back to 1000F where it goes to the HP turbine again. Continuous cycle.

If the theory of heat extraction was not valid there would not be a 20% increase in HP at the Turbine Shaft after the Reheating Cycle. Which there is. Once again the pressure is in steady decline from the exit of the boiler feed pump all the way to the condenser which proves it is a secondary function. Pressure is not the primary force at work here. It is merely the vehicle with which the heat bearing medium is moved thru the system.

Many people feel the steam should increase in pressure after being reheated. However if this were true the steam would not flow in only one direction. There are no check valves in this system. It is a one way trip from Boiler Feed PP to Condenser and the reheating of the steam increases the efficiency by 20%. They wouldn't do it if it didn't work. This same technology was applied to the Largest Steam Powered Locomotives which used a reheat cycle between the smaller HP cylinders and the much larger Low Pressure cylinders. These were Piston Driven External Combustion Heat Extraction Machines.

An Internal Combustion engine works the same way, as does a bullet in the barrel. And yes, pressure is large part of the force involved, but it is not all of the force. If Pressure was the only force involved then Velocity would be a direct function of pressure.

We know that it is not.

I do not expect everyone to understand this concept. I was the only one out of 40 in the Southern California Edison Steam School who got the Essay Explanation of the Answer right on the Final Exam and I graduated #1 in that class.

I was the only person who was receptive to this concept as everyone else had a preconceived notion that a steam turbine was nothing more that an expensive Pinwheel.

They paid me to go to this school!

I have argued this point 100 times since. It is not widely understood.

The reason why an engine running on Nitro Methane produces more HP than the same engine running on Alcohol is because the Nitro burns hotter and faster IE; there is more energy in the fuel. That energy is Heat Energy not pressure energy. This is also why Diesel engines produce more power than gas engines do for a given size. More energy in the fuel.

If it was pressure energy then the engine would have to absorb 4-6 times the pressure that the same engine running on Alcohol would. This can't be true as the two engines are virtually identical in construction.

The concept is everywhere around us however it is only taught in very specialized arenas, it is not even understood well in those arenas. I was 1 out of 40 and the only other one in the room who understood it was the teacher. He spent extra time with me because I had Jet Engine experience. I understood it perfectly then and now.

YMMV.

Light is both Waves and Particles,,, Those particles are Electrons. The little whirly gig that looks like a light bulb and has the four diamonds on a pinwheel that rotates when exposed to light in the direction away from the black surfaces,,, works in EXACTLY the same way as an engine or a bullet ! The black absorbs more heat than the white which excites and expels more electrons which makes the thing turn away from the black surfaces. The only pressure being exerted in this case is the opposite and equal reaction of the electrons moving away from the black surface.( like recoil?) That pressure would not exist without the electron's movement.

I got my first one of these gadgets in 1956. I knew it worked but I didn't fully understand why until 20 years later. It is the simplest example of this concept that I know of.

Randy

[dtknowles]

I understood what you just said because I had a college education in physics and chemistry. I would bet that it went right over a lot of people who reload though. Many simply do not have the background or vocabulary for that.
If you could find a simpler/plainer way of stating what you just said, I think it would be better.

Lets try this, some powders get more velocity at lower pressures because they push the bullet with less force but for a longer time but that is not quite right because they are pushing harder near the muzzle than other powders.

So lets say that they do not peak at as high a pressure but the average pressure is higher.

Tim

[dtknowles]

Tim: I used the heat extraction example to show there are other forces working.

The heat extraction of and internal combustion engine is a concept that not many can understand because really it makes little sense. However it is fact.

The heat being extracted from the combustion cycle increases the electron activity on the top of the piston and it does influence motion of the piston. Most all of those electrons are being expelled from the top surface of the piston being bounced off the top of the combustion chamber and back off the top of the piston. This is the primary force at work. The pressure generated is secondary and would not exist without the electron movement.................
Randy

Electrons are not expelled from the top of the piston in an internal combustion engine. At least not enough to produce measureable power.

Tim

[dtknowles]

............Light is both Waves and Particles,,, Those particles are Electrons. The little whirly gig that looks like a light bulb and has the four diamonds on a pinwheel that rotates when exposed to light in the direction away from the black surfaces,,, works in EXACTLY the same way as an engine or a bullet ! The black absorbs more heat than the white which excites and expels more electrons which makes the thing turn away from the black surfaces. The only pressure being exerted in this case is the opposite and equal reaction of the electrons moving away from the black surface.( like recoil?) That pressure would not exist without the electron's movement.

I got my first one of these gadgets in 1956. I knew it worked but I didn't fully understand why until 20 years later. It is the simplest example of this concept that I know of.

Randy

Randy.

Those particles/waves you are talking about are not electrons they are photons, they are produced when an electron changes its energy state relating to its "orbit" around the nuclei of atoms/molecules.

Your other discussions of heat transfer do not properly address the relationship between pressure and temperature. In both the internal combustion engine and a gun barrel the pressure is created in two ways, first is the chemical transformation of the solid or liquid fuel into a gas and second it the heating of that gas by that chemical reaction. The more gas created the more pressure and the hotter the gas the more pressure. Heat is transferred in three ways, conduction, convection and radiation, that radiation is in the form of the photons I mentioned earlier. Those photons come from the combustion products and do heat other combustion products and can be reflected off the base of the bullet but they have very small mass and their contribution to the bullets velocity is miniscule. If the toy you described earlier could produce useable torque we would have had solar powered turbines a hundred years ago.

Tim

[mikeg1005]

Lets try this, some powders get more velocity at lower pressures because they push the bullet with less force but for a longer time but that is not quite right because they are pushing harder near the muzzle than other powders.

So lets say that they do not peak at as high a pressure but the average pressure is higher.

Tim

I know what you are saying but its kind of misleading with this statement for people who don't get the math behind "why" it goes faster... its not you get higher velocity at lower pressure, you get higher velocity because the powder doesn't peak pressure as quickly. A full charge of clays and a full charge of H110 both max out at SAAMI max pressure, but one gives more velocity because like you said the area under the curve of the pressure over time graph from t0 to t(when bullet leaves the barrel) is higher.

[mikeg1005]

Obviously the maximum load for any given firearm is the one that burns all of the powder just before it exceeds the firearms ability to contain the pressure. However the term Maximum Load is misleading. It should be "Maximum Safe Load," since a maximum safe load will contain a certain percentage of safety margin built in to deal with unforeseen variables, and to keep everybody out of trouble. Morons included.


I don't complete agree with what you said above. For all intents and purposes, peak pressure occurs within the first few milliseconds of ignition... pretty much when the bullet runs into the lands of the rifling. Pressure does not max out inside the barrel as the bullet is traveling down it, because the volume of the chamber (barrel) is increasing at an exponential rate and powder combustion can't keep up with this.

This is a reason that a gun that kabooms always kabooms in the chamber.

You are correct on the "max safe load"... my example of the guys running 9mm major in barrel at aren't any different than normal 9mm Luger barrels in 1911s in USPSA open division. Its not uncommon to reach pressure of 50k in these guns.

[W.R.Buchanan]

Yes Tim and a Photon has zero mass and that is why their impact is negligible however they also can transfer energy to electrons and that reaction and resultant heat are exactly what I am talking about. That is the primary force I describe. The electron excitement does not have to come from only Photon impact as any heat source can generate accelerated movement. That energy can be transferred by any of the 3 methods to do work.

Everything else is as a result of this primary action.

The force generated is all about volume. IE; the more electrons you excite the more work you can do.

Energy is not pressure. Pressure is an accumulation of energy. The things you are talking about are all secondary forces. The excited electron movement generated by the heat of combustion is what is generating the pressure, and thus doing the work.

You say that their influence is miniscule, however in sufficient volume they are called Atomic Bombs which is nothing more than a large quantity of electrons flying around colliding with big atoms which have unstable amounts of electrons that get knocked off and go on to collide with others and so on. Enormous amounts of Energy being released is the result, and accelerating electrons going in all direction create shockwaves, and the heat flashes the atmosphere to steam, and also burns everything in sight. The chain reaction is ALL about excited Electron movement in the beginning and that is amplified by the energy released everytime one collides with a bunch more.

Very familiar with the methods of energy transfer. Power Generation and Transmission are pretty much all about Energy Transfer, and all forms are part of the show.

I love the part in Global Warming where they conveniently leave out the fluctuating amount of Radiation we receive from the big light bulb and blame it all on mans use of fossil fuels. Talk about the influence of Photons? Mans influence pales in comparison.

Randy

[W.R.Buchanan]

I don't complete agree with what you said above. For all intents and purposes, peak pressure occurs within the first few milliseconds of ignition... pretty much when the bullet runs into the lands of the rifling. Pressure does not max out inside the barrel as the bullet is traveling down it, because the volume of the chamber (barrel) is increasing at an exponential rate and powder combustion can't keep up with this.


Mike: If this were true then there would be no need for Rifles, and at 50,000 psi it damn sure can keep up with the increasing barrel volume, because the volume of gas created expands much faster than the volume of the barrel or else the bullet would lurch forward and quit.. Peak pressure is reached as soon as all the powder is burned. Obviously in pistols this can happen faster, but irrespective of barrel length or time of combustion Smokeless powder still burns in a progressive manner. The shorter the barrel the faster it must combust or whatever doesn't combust is wasted.

Black powder burns instantly that is why it is classed as an explosive, however the fuel in the mix doesn't have the energy content that Nitroglycerin has and that is why smokeless powders have properties that slow the burn rate down. IE Bullseye and many others are 40% nitro, the rest of the mix is burn inhibitors. Pure Nitro Glycerin burns really fast. Much faster than BP and as such there is more energy due to the improved fuel.

All explosives are rated in potency by measuring the Feet Per Second that they burn. The faster they burn the bigger the bang.

Randy

[W.R.Buchanan]

So lets say that they do not peak at as high a pressure but the average pressure is higher.
Tim

You might be on to something there.

We should consult the electrons for verification.

They also contain all knowledge and thus know all.

Randy

[dubber123]

I believe it was John Linebaugh you tested WW296/H-110 and said it had a smooth, linear curve to I believe 90,000 Psi. He has the equipment to test this, and has run deliberate destruction tests on revolvers to determine their strength. I trust him when he states something. If the OP has a strong revolver, such as the GP-100 mentioned, I would simply work up until extraction or some other warning sign presented itself, and then back down until that sign went away. Load data for .357 is greatly reduced from the early days. If that early data was so dangerous, there would be a lot less of those early .357's left to command such a high price at auction time. If you use your head, you don't have to be afraid to try new things. And as stated, don't be surprised if absolute max doesn't shoot the best. Good luck, and have fun.

[tazman]

I believe it was John Linebaugh you tested WW296/H-110 and said it had a smooth, linear curve to I believe 90,000 Psi. He has the equipment to test this, and has run deliberate destruction tests on revolvers to determine their strength. I trust him when he states something. If the OP has a strong revolver, such as the GP-100 mentioned, I would simply work up until extraction or some other warning sign presented itself, and then back down until that sign went away. Load data for .357 is greatly reduced from the early days. If that early data was so dangerous, there would be a lot less of those early .357's left to command such a high price at auction time. If you use your head, you don't have to be afraid to try new things. And as stated, don't be surprised if absolute max doesn't shoot the best. Good luck, and have fun.

Well put.

[leadman]

Could it be that the older 357 guns command a higher price because there are fewer of them left in good condition? Actually the supposed reason that the pressure is lower now is due to the smaller, lighter guns produced in 357 mag.
No matter the reason the pressure was lowered there is not much in the way of velocity gained by exceeding powder company load data.
As an individual loading in my garage I have little in the way of checking the pressure in my cases when fired. I have seen cases expand several thousands with loads well within the data and also primers flatten with published loads.

Seems to be a big variance in the strength of handgun cases and primer cups. There is alot of data out there that does not specify the primer used or the reloader does not have the listed primer so uses what he has. This could get the load over the max pressure but fortunately this normally won't cause a blown up gun.
A-Square had published data years ago on the 7mm Rem magnum with 2 different primers. Just the primer change accounted for over 6,000 psi in additional pressure.

[dtknowles]

You say that their influence is miniscule, however in sufficient volume they are called Atomic Bombs which is nothing more than a large quantity of electrons flying around colliding with big atoms which have unstable amounts of electrons that get knocked off and go on to collide with others and so on. Enormous amounts of Energy being released is the result, and accelerating electrons going in all direction create shockwaves, and the heat flashes the atmosphere to steam, and also burns everything in sight. The chain reaction is ALL about excited Electron movement in the beginning and that is amplified by the energy released everytime one collides with a bunch more.

Randy

No, in an atomic reaction the energy liberated is in the form of neutrons, they transfer energy to the system by collisions, sort of all three of the heat transfer functions combined. Electrons get into the act and sure massive amounts of photons as well. Heat and pressure are the final result but not until after the gamma rays (photons) and neutrons have taken their toll.

Tim

[mikeg1005]

Mike: If this were true then there would be no need for Rifles, and at 50,000 psi it damn sure can keep up with the increasing barrel volume, because the volume of gas created expands much faster than the volume of the barrel or else the bullet would lurch forward and quit.. Peak pressure is reached as soon as all the powder is burned. Obviously in pistols this can happen faster, but irrespective of barrel length or time of combustion Smokeless powder still burns in a progressive manner. The shorter the barrel the faster it must combust or whatever doesn't combust is wasted



Randy

Randy,

I guess we'll have to agree to disagree. Peak pressure does NOT occur when all powder is burned.

http://firearmsdesigner.com/?p=234

Take a look at those two graphs... notice how the pressure peaks occur basically at the end of the chamber in terms of length in both 223 and 45acp that were tested. Unless you are suggesting that all powder is 100% burned before the bullet travels any serious distance down the barrel, it clearly shows that peak pressure is at the very beginning of bullet movement... and not when the powder is burned up.

The above link is only one of many tests showing this.

It appears to me... that you are confusing with peak pressure with average pressure. Rifles have faster velocities because they operate at higher pressure AND because slower burning powder, burns longer, generating gas longer, and as a result push the bullet longer.... higher AVERAGE pressure. From a mathematical standpoint this is proven to be true because the area under the curve of the formula for pressure in a chamber with respect to time (dP/dt, not the right form but that's the integral) from t0 (time zero, ignition) to tE (time of bullet exiting the barrel) is larger for a slower burning powder vs. a fast burning powder.


A bullet will always accelerate in a barrel so long as the force of the pressure of the expanding gases is higher than the force of the friction in the barrel. Again, if your theory of peak pressure hit at the point when all powder was burned, then when you would get faster acceleration in the end of a barrel vs. the beginning and we know this is not true.

Think snub nose revolver... a 125gr load that goes 900fps in a 2" barrel will only gain a few 100fps in a 4-6" barrel. Acceleration decrease as barrel length extends... the reason is because the pressure in the barrel is lower as the volume of the barrel expands. If the your concept held through then we would see a 900fps acceleration in the 4-6" barrel portion rather than the 0-2" barrel portion of a 6" revo.

[mikeg1005]

The 46th ed. of Lyman's shows a Lyman 385133 (160gr LRN) with a max charge of 18.3gr of H110 when sat into the crimp groove... I confirmed it with a few people. Dimensions of the 358133 show the base to crimp groove to be .340" ... I took a piece of federal brass, trimmed it by .340" (after sizing) and filled it to the top, powder charge weighed in at 18.2gr on my charge master. Max charge occurred at 100% fill capacity according to that book.

Kind of interesting. I have no interest on trying this, just seeing how much the theory holds up with the 100% fill = max.

[jonp]

In a closed system I would think peak pressure would be produced when all of the powder was burned but in a cartridge where the bullet acts as a relief valve I think peak pressure would occur at the point the bullet is forced from the brass. At that point the volume of the container increases causing the pressure to drop?

[44man]

Seen a few things that don't make sense to me. BP does NOT explode or ignite all at once, it also will burn progressive. You will reach a point where a lot of it does not burn in a barrel and the additional powder weight will REDUCE velocity. You can compress too far and shoot plugs out the muzzle. BP is a poor generator of gas so pressures are lower, yet a longer barrel makes better use of it.
A test was done long ago with a strong pipe with caps screwed on each end. The pipe was filled with BP and a fuse lit, all the pressure escaped the fuse hole, no kaboom. Things would be different without a fuse hole but you can see what the gap on a revolver does.
You can over load 296/H110 without sticking brass in SOME CALIBERS but not others. It does not spike and like JL's tests show, you can be over pressure without pressure signs so it is a hidden danger.
The boolit is important, I have two almost identical for my .475 but one has a GC. The same load I use with the PB will stick brass with the GC boolit, had to back down. Seating depth is the same for both. If you fool to 100%, make sure it is to a boolit base ONLY and work up slowly, I did not reach that point to stick brass in the .475. Primers are no indication, ignore that.
True that peak is extended out with slower powders and it still burns and adds to boolit push because all does not burn all at once. Powder weight can still raise pressures even if a boolit has started slower. Your 17,000 psi with a fast powders are worse on a boolit then 40,000 average pressures.
It is why I found medium powders like 3031 and 4895 work better in a 30-30/ 45-70 rifle then Unique/ 4227. The peak is too soon. 3031 will not all burn in a 10" 45-70 revolver and there is unburned powder in the case and on the bench. Puts to rest that "expert" that said all powder is burned in less then an inch. The guy I had trouble with all the time and I asked how he handles 88 gr of 4831 in a .300 Weatherby if it all ignites in the case.
Also why I say to shorten handgun barrels too much will make slow powders fail. Silly to shorten a .454, 45-70 or .500. All you get is a huge flame out front and can't reach velocity or spin. A response will be "I get 1100 fps" when the boolit they use needs 1300 fps.
Hard nut to crack guys. Yeah even a .357 with a 2" barrel is only a very loud .38 with more flame and fire.

[44man]

I remember an old guy that shot IHMSA with a .357 S&W. After every round he went to a stake in the ground to pound the extractor to remove brass. No idea what he shot but seen him do it for years. I wonder what the gun is like?
Then a friend has an older Vaquero like mine. .45 Colt. He bought 335 gr LBT'S and was told to work up from 19 gr of 296 until he got pressure signs. Not to be, he went to 30 gr without stuck brass, now don't ask how he got that much in, I don't know! But I turned white so PLEASE DON'T try it. A tribute to Ruger though.
I really do worry about a few. 100% does NOT mean to the case mouth. How in the world do you get 30 gr in a .45 Colt???

[jonp]

"30 gr without stuck brass"? I've followed Mr. Linebaughs footsteps part of the way with my blackhawk but nowhere near that. Holy Moly! He must have compressed the H110 to get that in. I'm going to load one of my Starline 45Colts with that much to see what it looks like. I'd never shoot it.

[colt 357]

This is second hand info but a friend of mine knows a guy that was pushing the H110 loads. I don't know how much he was over but he ended up with two matching cylinder halfs and a cracked top strap. luckily no one was hurt left him dazed and shaken. My friend said he no longer goes over the max loads. Stick with the max loads

[MtGun44]

Go to Hodgdon's site, put in the cartridge, bullet weight and get the max safe load.

Anything above that is overpressure. Guns have safety margins, but intentionally going
beyond the tested data ( I have toured Hodgdon's data gathering lab, and they have the
most modern equipment, so the data is good) is asking to damage a gun.

Shows pretty poor judgement, this is the kind of stuff that gives reloading a
bad name. I won't be doing it.

Bill

[H110]

As you can tell by my name, H110 is a favorite powder of mine (love the smell). I have went through a few pounds over the years so here is my take. I use this powder exclusively in 45 Colts and 454. H110 is one of the most stable powders on the market today as long as you keep pressure up where it is happy. It is very pressure sensitive and demands it for stability. With all that said it is very unforgiving as well. I am telling you from experience, what is so weird about it is flattened primers and or sticky extraction mean nothing. You can blow up a gun with it and the cases may fall out of the cylinder. It is more finicky in some guns and not others. I always use a Chronograph when working up loads with this powder, I will not do it without it. I have found that when spreads come down and stabilize it is happy and so am I. As far as filling cases to the base of the bullet because someone, the net, or anyone said to, NOT. Use a good manual, common sense and let the charge be what it is. By the way don't down load H110 this makes it unhappy.

H110.

[colt 357]

As you can tell by my name, H110 is a favorite powder of mine (love the smell). I have went through a few pounds over the years so here is my take. I use this powder exclusively in 45 Colts and 454. H110 is one of the most stable powders on the market today as long as you keep pressure up where it is happy. It is very pressure sensitive and demands it for stability. With all that said it is very unforgiving as well. I am telling you from experience, what is so weird about it is flattened primers and or sticky extraction mean nothing. You can blow up a gun with it and the cases may fall out of the cylinder. It is more finicky in some guns and not others. I always use a Chronograph when working up loads with this powder, I will not do it without it. I have found that when spreads come down and stabilize it is happy and so am I. As far as filling cases to the base of the bullet because someone, the net, or anyone said to, NOT. Use a good manual, common sense and let the charge be what it is. By the way don't down load H110 this makes it unhappy.

H110.

yea dont down load this can cause a boolit to be lodge in the bore. it has a small load range were it is happy

[Tar Heel]

Go to Hodgdon's site, put in the cartridge, bullet weight and get the max safe load.

Anything above that is overpressure. Guns have safety margins, but intentionally going
beyond the tested data ( I have toured Hodgdon's data gathering lab, and they have the
most modern equipment, so the data is good) is asking to damage a gun.

Shows pretty poor judgement, this is the kind of stuff that gives reloading a
bad name. I won't be doing it.

Bill

I am one of the nine out of ten handloaders who agree with MtGun44. The 10'th one can't type anymore.

[44man]

Good to read a lot of common sense.
What I like about 296/H110 is how easy it is to find a load. Groups tighten smoothly, get best and then start to open at the same rate they got better. Back down to the most accurate. I don't see that with powders like Unique, 7 gr shoots the same as 10 in the .44. If you shoot 8.1 gr, that .1 gr sure doesn't mean anything. Seems all you get is more velocity. My targets all look the same.

[dubber123]

I look at it differently. Powder companies need to print data that is safe in all guns of a given caliber. Back when they were all N-frame S&W's it was easy, then came the Blackhawk, probably even stronger. Then the K-frame S&W's, obviously weaker. Now we have 5 shot lightweight snubbies imported from who knows where. It is no wonder the average pressures have been reduced. I have a Freedom Arms model 353 in .357. Back when the gun was new, it had data published for it that was totally unsafe in any other .357, but completely safe in that gun. In the same vein, there is a WIDE range of strengths available to firearms purchasers today, yet load data must only consider the weakest of the lot to be safe.

For sure, sticking to these published loads will be the safest way to do business, but it doesn't mean anything above them is necessarily unsafe. Without the ability to test pressures, you are on your own to work up loads. I feel safe doing so under certain circumstances, many here obviously don't share my opinion.

[fecmech]

I feel safe doing so under certain circumstances, many here obviously don't share my opinion.

I do also but we don't really know the abilities of the person we're posting our advice to on the web. The devil is always in the details so that's why I think people default to published loads only.

[44man]

I do also but we don't really know the abilities of the person we're posting our advice to on the web. The devil is always in the details so that's why I think people default to published loads only.
The best has always been a little under book max. I have worked over to find poor groups and there is no need for more velocity. Even strong guns like the Ruger, Freedom and BFR react best to under max. I think the BFR is a lot stronger then a Freedom but it still does not need shot to limits. Actually the faster twists come in at lower pressures. They both use Carpenter steels but the BFR is thicker. I believe the BFR is the strongest revolver ever made. But why push them?

[dubber123]

The best has always been a little under book max. I have worked over to find poor groups and there is no need for more velocity. Even strong guns like the Ruger, Freedom and BFR react best to under max. I think the BFR is a lot stronger then a Freedom but it still does not need shot to limits. Actually the faster twists come in at lower pressures. They both use Carpenter steels but the BFR is thicker. I believe the BFR is the strongest revolver ever made. But why push them?

Which book max? The new ones for the weak guns, or the older ones? In the F/A, BFR and others, 50,000+ Psi cartridges are the norm. .357 is limited by modern manuals to 30K and change, down from 40K and change of the original loadings. There is a performance difference, and I don't see why it can't be exploited in the appropriate firearm.

[44man]

Which book max? The new ones for the weak guns, or the older ones? In the F/A, BFR and others, 50,000+ Psi cartridges are the norm. .357 is limited by modern manuals to 30K and change, down from 40K and change of the original loadings. There is a performance difference, and I don't see why it can't be exploited in the appropriate firearm.
Based on the gun, Ruger only loads. The benchmark for strength. The BFR is actually a larger Ruger, castings from Pine Tree. The Freedom is strong. Same steel I believe.
To exploit is still not right. so if your revolver can shoot 50-55,000 psi, don't look for 70,000.
Most .357's are smaller so you still need to have judgement. If you have a .357 in a .500 cylinder and frame, what can I say?
Funny thing is we tested the Freedom .357 with normal IHMSA loads and Bob Baker said we were way over. Loads taken from the IHMSA book. 14 gr of 296 with a 158 gr is not hot. If the Freedom is so strong, why were we admonished? Most shoot 16 gr with a 170 gr.

[dubber123]

Based on the gun, Ruger only loads. The benchmark for strength. The BFR is actually a larger Ruger, castings from Pine Tree. The Freedom is strong. Same steel I believe.
To exploit is still not right. so if your revolver can shoot 50-55,000 psi, don't look for 70,000.
Most .357's are smaller so you still need to have judgement. If you have a .357 in a .500 cylinder and frame, what can I say?
Funny thing is we tested the Freedom .357 with normal IHMSA loads and Bob Baker said we were way over. Loads taken from the IHMSA book. 14 gr of 296 with a 158 gr is not hot. If the Freedom is so strong, why were we admonished? Most shoot 16 gr with a 170 gr.

Worried about sue happy individuals? When the gun came out, (the F/A .357), there were some super hot loads printed, and they aren't hard to find, I did just recently. I know the velocities you get with your .475, they are the same I get, and I will bet money they are in the 40+ K range. Why a strong .357 has to be limited to 30K loads is beyond me. I know why the powder manufacturers do it, they don't know what gun they will end up in. A GP-100 is not a J-frame or off shore equivalent.

[44man]

Worried about sue happy individuals? When the gun came out, (the F/A .357), there were some super hot loads printed, and they aren't hard to find, I did just recently. I know the velocities you get with your .475, they are the same I get, and I will bet money they are in the 40+ K range. Why a strong .357 has to be limited to 30K loads is beyond me. I know why the powder manufacturers do it, they don't know what gun they will end up in. A GP-100 is not a J-frame or off shore equivalent.
Exactly, The right .357 should do 60,000 but you need steel around the case. can you imagine a .357 in a BFR .475 frame and cylinder? Five shot. What a hummer you would have!

[daniel lawecki]

Ruger gp 100 I shoot a 158 SWC over H110 between 13.3 - 14.5 never saw a need to go higher than that.:mrgreen:

[silverado]

I stick with the idea that if your 357 loads are not powerful enough, maybe you should get a 44...

[44man]

There is also the .357 max.
But what I found with hard cast and too much velocity when hunting deer, You will need a little expansion. A hard boolit has limits no matter the meplat. It is strange to see a .500 WFN pop through deer like a paper target and leave little internal damage. Same with a hard 45-70 WFN.
With the same alloy and hardness, the heavy boolit from a .45 Colt at 1160 fps kills faster then the same alloy from the 45-70 revolver at 1630 fps. Same weight boolits. The .44 kills faster and the .475 best of all.
Expand the 45-70 too much and you will lose a lot of meat.

[fouronesix]

Oh shoot, :( I was just beginning to enjoy the debate about energy produced by a nuclear reaction and it's not even close to what happens in a chemical reaction. The secret, which is quite well known by the way, is that a tiny bit of matter is converted into energy. You know the e=m(cxc) stuff. At the atomic scale you kinda have to have an idea of how quantum physics works.

[44man]

I hope I made it clear that 100% load density is just no air space below the boolit when seated. This has never caused me a problem, yet I have worked to a sticky case with one boolit in the .475. I have two boolits and one is a GC design. The load I use with my PB will stick brass with the GC even though they are almost exactly the same seating depth and weight.
Sticky brass is the only way I know to tell if you are over with 296, primers mean nothing at all. I never seen the powder spike even when a friend went to a gross over load in his old Vaquero.
Don't ever try this but he went to 30 gr of 296 with a 335 gr LBT and no, I have no idea how he got all that in a Colt case. He still did not stick brass.
I watched an old guy shoot IHMSA for years with a S&W .357, never learned what powder he used but he always went to a 2X2 in the ground to beat his extractor on to get brass out. He never hit much but steel still refused to fall if he did hit. I could not convince him he would be better off with accuracy and hit steel high.

[Tatume]

According to several of the gun magazine writers that I respect, including Brian Pierce and John Barsness, pressure that will cause cases to stick in revolver chambers is very much over maximum. They have written that even proof loads that are 150% of SAAMI max pressure will not cause cases to stick. Pierce recently observed the firing of proof loads and claimed that the cases practically fell from the chambers.

[44man]

That is why pressure signs are so hard to see in revolvers. Most boolit makers say to work up until you see pressure signs but that just doesn't work.
I was shooting 4198 with jacketed in my BFR 45-70, shot great but when I went to a cast of the same weight, things started fine, accuracy and normal velocity with weighed trapdoor loads. Then a shot exceeded 1800 fps and stuck a case. I quit shooting the powder then and there.

[leftiye]

According to several of the gun magazine writers that I respect, including Brian Pierce and John Barsness, pressure that will cause cases to stick in revolver chambers is very much over maximum. They have written that even proof loads that are 150% of SAAMI max pressure will not cause cases to stick. Pierce recently observed the firing of proof loads and claimed that the cases practically fell from the chambers.

Remember that maximum is a SAAMI value that in many cases isn't about what is safe in modern strong weapons, but that reflect what was maximum traditionally in guns of that caliber. So 150% of max (as in 45-70, 45 Colt) may not be a numerically impressive pressure that threatens the gun unless it is old or a weak design.. Stuck cases are overly hot, and one should back off, those loads should not be used, etc.. They indicate that the weapon's chamber(s) is/are flexing. But they aren't crisis level dangerous necessarily, even then. The problem is, it's a real scary question how close they actually come to the weapon's strength limits. There's not another pressure sign that will let you know except a bulged chamber or worse.

I have a bunch of .445 cases that I made from .303 brass. They are fire forming loads that were mild until I put a new cylinder on my Dam Wethon. Now they stick. I thimk the new cyl has shorter chambers.

[leftiye]

[With the same alloy and hardness, the heavy boolit from a .45 Colt at 1160 fps kills faster then the same alloy from the 45-70 revolver at 1630 fps. 44Man]

Dwell time in the flesh. .308 sniper bullets kill better at 600 yds than they do in closer too.

[44man]

[With the same alloy and hardness, the heavy boolit from a .45 Colt at 1160 fps kills faster then the same alloy from the 45-70 revolver at 1630 fps. 44Man]

Dwell time in the flesh. .308 sniper bullets kill better at 600 yds than they do in closer too.
Exactly, glad to see you are a believer. It took some time after losing deer to see a huge pressure wave from a flat meplat can move tissue out of the way.
I had fallen into the trap that all you need is a flat nose. The old saw of a .45 is the same as an expanded .30 holds no water.