Confused about reloading data charts - want to be safe

[BruceM]

It's quite a common suggestion.

OK, lets do this again. By whom? The reloading manual publishers?

To me,FREDJ338's approach makes sense.

I assume you speaking to "averaging" data from three or more previously "vetted" sources. My questions are:

1. How do you "vet" loading data?
2. If the data is "vetted", what is the need to average it if you follow Rule#1.
3. You feel it is wise to essentially interpolate and/or extrapolate data from supposedly "vetted sources", thereby in essence creating your own data without doing the lab work? To me, this means you essentially do not trust data you "vetted" on your own. As far as accounting for differences in individual guns, that is why you start low and work up (Rule#1). That is, of course, unless you know of a verified overpressure event when using anybody's published minimum or starting load. Again, we're taliking about minimum charges and NOT "middle of the road" loads.

Bruce

 

[rwsmith]

Signs of pressure......

About the only reliable 'sign' of pressure that I know is sticky extraction where there was none (as long as the chambers are smooth). Primer flattening may or may not be a sign of over pressure.

I think the 'working up' of a load give you a chance to stop before you go too far and the next pressure sign will be a cracked cylinder before you go far enough to 'disassemble' a gun and bend the top strap backwards.

 

[fredj338]

I'm just a little curious here. This is suggested by WHOM?

Bruce

By handloaders that have loaded 100s of 10000s of rds of dozens of calibers. The more data points the better.

 

[fredj338]

OK, lets do this again. By whom? The reloading manual publishers?



I assume you speaking to "averaging" data from three or more previously "vetted" sources. My questions are:

1. How do you "vet" loading data?
2. If the data is "vetted", what is the need to average it if you follow Rule#1.
3. You feel it is wise to essentially interpolate and/or extrapolate data from supposedly "vetted sources", thereby in essence creating your own data without doing the lab work? To me, this means you essentially do not trust data you "vetted" on your own. As far as accounting for differences in individual guns, that is why you start low and work up (Rule#1). That is, of course, unless you know of a verified overpressure event when using anybody's published minimum or starting load. Again, we're taliking about minimum charges and NOT "middle of the road" loads.

Bruce

Vetted data; data that is published, often pressure yested, not from your grampas notes,
Why averahe data, because test playforms vary so much, thus results vary so much.
Bruce you should know this.

 

[BruceM]

Bruce you should know this

.

What I know is that what you propose makes zero sense in either logic or science.

Do you know of any data published in manuals by major players which is not pressure tested? Incidentally, just because pressures are not printed does not means that loads were not pressure tested.

I happen to agree in that you should not use grandpa's notes as a substitute for published load data. You can also get yourself in trouble by trusting your own memory sometimes so in that instance, it never hurts to double check.

Regarding test platform variations; have you ever seen a documented case of an overpressure event using anybody's minimum or starting charge in any platform? This all goes back to developing loads for your gun(s). As a side note, what do you think would happen to factory ammo for modern centerfire rounds if the manufacturer's approached thing as you approach handloading. Just to be safe because of "varying launch platforms", all ammo would be loaded to bare minimums of pressure. While this happens on a limited basis for some rounds where ancient firearms of questionable metalurgy are in service or other reasons specific to that particular round, the industry could not survive if they approach thing in "running scared" mode.

Personally, I believe in taking all reasonable precautions when handloading. That said, not trusting load data I've purchased to work in my guns is not reasonable in my view. It is not reasonable to distrust everything. Further, when you start searching multiple sources for the answer to the same question regarding load data, finding variances is a foregone conclusion-a self fulfilling prophecy. At some point you HAVE TO TRUST SOMETHING. You cannot and really should not second guess everything and everybody. It's foolish to adopt an attitude that if 30 MPH is safe, 15 MPH is twice as safe.

Again, if you follow Rule#1, have you ever heard of a verified kaBoom event when using a starting or minimum charge-ever? Serious accidents are invariably caused by human errors such as using the wrong propellant, misreading a book or scale or a double charge. They absolutely are not caused by using a minimum charge published by anybody reputable as a starting point for load development. If, on the other hand, you have a valid reason for not trusting data published by somebody, you should not have purchased it (or gone to their website) in the first place. One thing you should not have in your possession is load data you doubt.

In the end, everybody needs to do what they feel is in the best interests of themselves. However, suggesting these silly reduncencies and what is essentially re-inventing the wheel to somebody else is well................

Bruce

 

[johngalt]

I think that part of the variation is due to seating depth. I've noticed that the manuals use different OAL. Remember that OAL is part of the recipe, it isn't just bullet weight and powder charge.

On pressure - I've never seen a manual that stated that flattened primers and sticky extraction are valid signs of over pressure in pistols. Those signs are in reference to rifles. Those signs don't appear until far far beyond most pistol pressures.

 

[ChiefStealth]

I use Grandpa's notes... so long as they are close to my Speer book, and the Hodgdon web site, and the bullet makers' data. Regardless of where the data comes from... verify with other sources. Throw out anything that is wonky. Start with a good margin of safety. Work up to your goal. Stop, and back off if you see signs.

 

[jimmy.jet]

Old manuals:
Freebie manuals

 

[rwsmith]

Thanks, I pretty much meant that...

I think that part of the variation is due to seating depth. I've noticed that the manuals use different OAL. Remember that OAL is part of the recipe, it isn't just bullet weight and powder charge.

On pressure - I've never seen a manual that stated that flattened primers and sticky extraction are valid signs of over pressure in pistols. Those signs are in reference to rifles. Those signs don't appear until far far beyond most pistol pressures.

Thanks for clearing me up. I was trying to say that there is mostly likely very little notice that a pistol load is approaching or going beyond max, until a cylinder gets cracked, which is better than the whole thing coming apart. Hence, working up is a good idea so that if there is a casualty, it's at least going to be a milder one than a real kaboom.

 

[Wise_A]

I do like pressure data to be shown because most of us have no way of determining pressure.

I just look at the general range of pressure for spec'ing bullet hardness. And sort of a pointlessly optimistic hope of being able to eyeball accurate bullet-powder-charge combinations by eyeballing my data.

On pressure - I've never seen a manual that stated that flattened primers and sticky extraction are valid signs of over pressure in pistols. Those signs are in reference to rifles. Those signs don't appear until far far beyond most pistol pressures.

Agreed. I've loaded some pretty hot .38 and .44, and the cases were only ever-so-slightly more difficult to extract.

Regarding test platform variations; have you ever seen a documented case of an overpressure event using anybody's minimum or starting charge in any platform? This all goes back to developing loads for your gun(s). As a side note, what do you think would happen to factory ammo for modern centerfire rounds if the manufacturer's approached thing as you approach handloading. Just to be safe because of "varying launch platforms", all ammo would be loaded to bare minimums of pressure. While this happens on a limited basis for some rounds where ancient firearms of questionable metalurgy are in service or other reasons specific to that particular round, the industry could not survive if they approach thing in "running scared" mode.

Oh, it's not the starting or minimum data I'm concerned about. That's actually never come up.

When I say "most conservative", I'm referring to the maximums. I triple-check that the intended load is less than the the lowest "Do Not Exceed" number, and triple-check that I loaded the correct powder.

It's not a matter of worrying over the pressure, it's sort of a margin-of-error thing I can happily indulge in because I'm never pushing velocity to its absolute limit. If I need or want more velocity, there's always a slower powder to switch to. This way, I figure that a few more bad things can happen before I lose fingers.

Just think--if you were loading incredibly light or right at the ragged edge of "Do Not Exceed", wouldn't you be more inclined to, say, verify or weigh every charge, than if you were loading comfortably in the middle? Same mentality.

Now--commerical ammunition factories, you really can't compare to. The powder isn't the same at all. The stuff we buy is called "canister powder", and it's really good stuff. This is because it has to conform to all the previous lots used, because reloaders have to be able to trust it against printed loading data. Even still, there's a bit of variation, lot-to-lot. I remember reading that volumetric density of the same powder is allowed to vary by as much as 16% lot-to-lot.

Factory ammo is produced with entirely different stuff. Each traincar full of powder can be a totally unique, special snowflake. Because what the factory is going to do is test that lot for velocity and pressure, and then cook up a load particular to that lot, using their existing OAL, crimp, primer, brass, and bullet dimensions. And I'd suspect that they probably trend towards middle-of-the-road, except in the case of specialist ammunition.

 

[BruceM]

Oh, it's not the starting or minimum data I'm concerned about. That's actually never come up.

So, you understand the first part of load development.

When I say "most conservative", I'm referring to the maximums. I triple-check that the intended load is less than the the lowest "Do Not Exceed" number, and triple-check that I loaded the correct powder.

It's not a matter of worrying over the pressure, it's sort of a margin-of-error thing I can happily indulge in because I'm never pushing velocity to its absolute limit. If I need or want more velocity, there's always a slower powder to switch to. This way, I figure that a few more bad things can happen before I lose fingers.

First of all, maximum and conservative are mutually exclusive terms when it comes to handloading. There is no such thing as a sort of, kind of maximum load the same as there is no such thing as "sorta pregnant". Finding a "lower" maximum bullet/charge weight combo in a different manual means absolutely zip, nada, zero, 19, zilch, scratch. The listed maximum charge was only maximum in their test gun or fixture based on their protocols, etc., etc., etc. It may be maximum, below maximum or higher than maximum in your gun with your lots of components under your atmospheric conditions at your elevation above sea level.

Just think--if you were loading incredibly light or right at the ragged edge of "Do Not Exceed", wouldn't you be more inclined to, say, verify or weigh every charge, than if you were loading comfortably in the middle? Same mentality.

No, no, no and no for the reason I outlined above. A lot of your thoughts and conclusions are base on you viewing the information you see in the books as "recipes" and not as data. Minimum charges do not concern me. If you feel you are approaching the "ragged edge" of maximum loads for your gun, you really need a chronograph to help you. Weighing charges depends on how the propellant I'm using meters thru my powder measure. Also, I never try to max. out fast or medium burning propellant in reduced power loads and then "switch" to a slower powder. I find it better to use a propellant which is suitable for the application in the first place. In low pressure rounds like .45 ACP, you will not see traditional pressure signs until you are way, way over maximum-hence the need for the chronograph. Even with magnum handgun rounds, things like flatened primers don't tell you much. In rifle rounds, measuring things like case head expansion can be a dicey proposition also. For dealing with honest to goodness maximum loads for you guns, the chrono is the best tool to have for the average handloader.

Here is an example of how much maximum loads can vary between guns. Back in the day, a very powerful but considered "safe" maximum load for the .357 magnum was 15 grains of Hercules 2400 below Lyman #358156 155 grain swc with a standard primer. I fired lots of those thru my python and they were, in fact, accurate and safe in my gun. One day at the range, a friend was trying out a new to him 5" M27 Smith. After he burned thru his ammo, he asked if he could try 6 of mine. He was an experienced handloader and was well aware of that particular load. He fired the six shot string tru the M27 and it produced the customary small cluster of holes in the downrange target. However, when he tapped the ejector rod to dump the empties, it absolutely would not budge. At home, he had to put the cylinder in a padded vice and tap the brass out with a wooden dowel. No damage to his gun but still a PITA just the same. No such problem with my gun(s). The point is that maximum loads vary from gun to gun and sometimes by a fair amount.

If you are this paranoid about maximum loads, perhaps you should wait for that until you have more experience or avoid that all together.

Bruce

P.S. As far as losing fingers, again, those types of catastrophic accidents are cause by the previously mentioned human errors. Keep in mind the proof loads are 30% above maximum SAAMI maximum pressures. You won't blow up a gun with a quarter grain overcharge.

 

[Wise_A]

Actually, I run pretty high up on my .44s, but not quite all the way up even by my reckoning. Middling on the .45 ACP because it has to feed through a bunch of different guns, and light on .38s.

The listed maximum charge was only maximum in their test gun or fixture based on their protocols, etc., etc., etc. It may be maximum, below maximum or higher than maximum in your gun with your lots of components under your atmospheric conditions at your elevation above sea level.

There is absolutely a never-exceed. That's why they have those words at the top of the column.

The bolded part is why I stick to the lowest of those numbers. Sure, I may be leaving some performance on the table, who give cares? Going hotter doesn't shrink groups, and they're not sticking in the paper.

No, no, no and no for the reason I outlined above. A lot of your thoughts and conclusions are base on you viewing the information you see in the books as "recipes" and not as data. Minimum charges do not concern me. If you feel you are approaching the "ragged edge" of maximum loads for your gun, you really need a chronograph to help you.

GET OUT OF MY BRAIN.

Actually, no, you're not psychic. Whether I weigh every charge or blitz along checking every 10th has to do with statistics and powder/weight selections. For instance, if I decide to hate myself one day and load 700-X into .38 Special, then I know I have to weigh every single charge or at least eyeball it. This is because my powder measure is unhappy trying to dispense a 3.0-grain charge of that bridge-crazy powder. It's usually within .1 grain, but the distribution is wide and the chances of a squib are high.

Switch over to 2.8 of Bullseye, or put 4.4 grains of 700-X into a .45, and I can go about as normal.

Same deal with .44 Magnum at the high side. If I'm running 10.7 grains of Unique, I have a lot more leeway on either side than if I'm using 11.4 (my preferred load), or if I decide to crank it all the way up to the 11.7-gr "Never Exceed".

Chronos are great for telling you whether your powder is unhappy, either through suddenly non-linear velocity gains or wildly inconsistent velocities. But you're not observing pressure directly, and velocity isn't necessarily tied to pressure, even within identical powders, guns, and conditions. To make matters worse, you're not even looking at what the velocity actually is, you're only seeing the velocity your gear is detecting.

I do agree that pressure signs do not necessarily manifest themselves even at Magnum pressures.

Here is an example of how much maximum loads can vary between guns. Back in the day, a very powerful but considered "safe" maximum load for the .357 magnum was 15 grains of Hercules 2400 below Lyman #358156 155 grain swc with a standard primer.

A lot of the old .357 Magnum loads were reduced, ironically, because they were re-tested with better equipment. The problem with the old CUP copper-crusher method is that it's really bad at detecting pressure spikes. So if you had a charge that delivered 35,000 CUP, but briefly (in charge-burning terms, heh) spiked to double or triple that, the copper cylinder wouldn't show that.

But if you look at it with modern electronic methods, it shows up plain as day and makes ballisticians turn white.

P.S. As far as losing fingers, again, those types of catastrophic accidents are cause by the previously mentioned human errors. Keep in mind the proof loads are 30% above maximum SAAMI maximum pressures. You won't blow up a gun with a quarter grain overcharge.

One, some of the variations in load data I see are a bit more than a quarter grain.

Two, I still don't want to run proof loads, or anything approaching them, through my gun.

 

[mikld]

A couple thoughts; first, I pay very little attention (none) to any forum expert, range rat, pet loads website, gun counter clerk or gun shop "guru" when it comes to load data, and I recommend this to any new reloader that will listen. For over 32 years all my reload data comes from published manuals (with a very few coming from powder manufacturer's websites, but checked against my manual). If one has a good number of reloads under his belt and understands powder charges and pressure signs, then he can "experiment" if he wants...

Reloading manuals and why you need more than two; Suppose you had 25 lab technicians in a room and you instructed them to go back to their labs and develop loads for a .32 Guzzbag Magnum. They all go back to their labs and use their own particular lot of bullets, powder, primers and brass (yep brass can differ a bit from lot to lot). They all use their own equipment, some use real guns and some use a universal receiver, with who knows how much wear and tear. Some may use state of the art electronic measuring equipment and some data may come from older equipment (and mebbe some copper crusher data), some in PSI and some in CUP. Some lab technicians may have extensive experience testing load data and some may see very little. So, will they all come back and report identical data?

 

[Steve C]

I also have some 148gr lead DEWC and some plated 125 gr TMJ bullets. I have 1 lb of Bullseye and Unique along with the HP-38.9

The 2 types of 148 gr WC bullets, hollow base and solid, are important to what data you use. The solid type are either double ended or bevel base.

Hollow base wad cutters are exceptionally accurate however the pressure of the round must be lighter than the SAAMI max available for solid based wad cutters. The hollow base is designed to expand into the rifling due to the pressure from the burning powder. Too much pressure and it can expand so tight in the bore that it tears off leaving a portion of the skirt in the bore or sealing the bullet so tight in the bore the it blows out the center of the bullet both situations leaving the remains as an obstruction.

Often data listed, esp on the more generic manufacturers websites, do not list the type of 148gr WC being used so they default to the lower charge that will be safe with hollow base bullets. Sometimes the data is designated as "target loads" where HB bullets are expected to be used.

Solid base wad cutters have no issue with the higher SAAMI max pressure and can be loaded with charges that will be close to what is recommended for the 158gr SWC/RN bullets.

 

[BruceM]

Reloading manuals and why you need more than two; Suppose you had 25 lab technicians in a room and you instructed them to go back to their labs and develop loads for a .32 Guzzbag Magnum. They all go back to their labs and use their own particular lot of bullets, powder, primers and brass (yep brass can differ a bit from lot to lot). They all use their own equipment, some use real guns and some use a universal receiver, with who knows how much wear and tear. Some may use state of the art electronic measuring equipment and some data may come from older equipment (and mebbe some copper crusher data), some in PSI and some in CUP. Some lab technicians may have extensive experience testing load data and some may see very little. So, will they all come back and report identical data?

You got this right. As a matter of fact, ACME labs can take their lots of components and equipment and gather data one day. They then can use the same equipment and lots of components the very next day and not be able to exactly duplicate the previous day's results. They themselves will tell you that and explain in detail why. When you buy multiple loading manuals, what you have actually done is procure more iterations of the previously mentioned and quoted scenarios. So. I don't know that having two, three or six copies of the same thing conclusively proves or disproves anything. There are way too many variables involved. This is also why what you see in reloading manuals is data and not recipes. With a "recipe" there is a reasonable expectation of an essentially identical result when exact ingredients and the prescribed amounts of them are assembled and prepaired in the instructed manner. Unfortunately, it doesn't work that way in handloading. This, incidentally, is why reloading manuals are just full of disclaimers of responsibility.

Incidentally Wise A, not all loading manuals admonish you to "never exceed" listed maximum loads. Many will, however, advise you to approach maximum loads listed with caution. Even then there are exceptions such as Olin instructing users of it's 296 load data to use the charges "exactly as listed" with no increases or reductions.

With regard to the .357 magnum load I mentioned, it was a commonly and widely used maximum load. As a matter of fact, Skeeter Skelton published it in the June 1988 edition of Shooting Times. Now I know that's awhile back but at that time we did actually have color tv's, microwave ovens, etc.. We even had indoor plumbing and cars did not have "Flintstone tires". That particular load showed neither extremely flat primers nor sticky extraction in my Python, Dan Wesson 715 or 6" M27. It was a safe maximum load in those guns. In my friends 5" M27, not so much.

Measuring each individual charge when dealing with what you feel is a maximum load or for that matter inspecting each individual kernel of propellant with a microscope if you wish may make you feel safer. Whether it does (make you and your ammo safer) as a matter of fact is another thing all together. Personally, it matters not to me.

Finally, I am aware of the basic concepts of the older CUP and LUP methods of pressure testing and the currently used piezoelectric method, not that it's all that new. So, don't feel that you're the Lone Ranger in this regard.

At any rate................

Bruce