How much is NOT enough?

Re: re: How much is NOT enough?

Overcrimped said:

You either forgot to mention, or omitted (for breavity's sake) crimp, case length and barrel fit.

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I didn't mention crimp firmness but case length is a factor in case capacity and barrel diameter (fit) is not a factor as detonation occurs long before the bullet reaches the barrel. At the most, theory has the bullet reaching the forcing cone of a revolver at the max. I also did not mention where in the case the powder charge is sitting and the angle the gun is being held as that affects the surface area of the powder exposed to the primer spark(s) or flame. Temperature was also not mentioned and that can have unexpected affects on things too.

Overcrimped said:

Inspired by another post, on this board, I am trying to work up a safe load for HBWCs in a .357 case. The problem is that all of the powder charges only give about 48% - 51% fill of the available space in the case. And that sounds a little low to me.

That is why I was asking for people's opinions, to see if I'm in the ballpark or not. Not to be called a fool, or foolish. I would gladly follow published minimums, if there were any, but there seems to be none.

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I'm sure there are minimums, in every data base I have or have seen, either a minimum or starting load is listed or the manual states the published is a maximum and to start at some percentage point lower than that of the published powder charge. Reread the boring and uninteresting areas of your sources and you should find this bit of info.

Overcrimped said:

My research into this my result in my learning why there is no load data for HBWCs in .357, it may be unsafe. But until I can find the answer(s), I shall continue the research.

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As there is no published data using the hollow based wadcutters in the 357 mag that I can find, though there are some for the double based wadcutter, it stands to reason no acceptable loads were developed for this bullet style. The added case capacity caused by the hollow base (relative to the flat base found on most other bullets and the outward bevel of the double ended wadcutter) is likely the culprit as the amount of powder needed to prevent detonation pushes velocities high enough to cause the bullet to skip or strip over the rifling leading to poor accuracy and excessive barrel leading. Putting "safe" though ineffective loads into a manual would probably negatively affect the reputation of the publication and ultimately affect their bottom line.

Overcrimp said:

Now you can help me by answering the question asked, or you can insult me. The choice is yours. Your answering the question just may help me to decide against such a foolish persute. Never can tell.

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I am sorry you thought I called you a fool, I meant it to refer to the actions you were contemplating. Every couple of weeks this general question is asked in the Cowboy Action circuit regarding reduced loads in the 45 Colt cartridge. As I mentioned in my first post, detonation has not been duplicated in the laboratory (at least to the best of my knowledge) but certain trends have been noticed. As also mentioned, there are many factors that lead to increased pressures which do not lend themselves to cut and dried rules. One combination of components may be safe within a certain temperature range or gun angle but act very differently when there is any sort of change. Same for the other components. That there is extreme difficulty replicating the results of detonation in test conditions makes determining "safe" levels impractical. Even in an ideal world, it would still be on a case by case basis as the percentage of case capacity needing to be filled would vary depending on components and cartridge. This is the best I can do, for better and likely more understandable explanations contact a couple of bullet and powder companies directly. I find Hodgdon and Speer to be the most helpful but the others are pretty good too.

uglydog said:

... barrel diameter (fit) is not a factor as detonation occurs long before the bullet reaches the barrel...

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Good point.

uglydog said:

...I'm sure there are minimums, in every data base I have or have seen,...

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I too, am sure there are minimums. Unfortunately, in this case, I have found none.

uglydog said:

...Reread the boring and uninteresting areas of your sources and you should find this bit of info...

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Actually, I find the "boring" areas quite interesting.

uglydog said:

As there is no published data using the hollow based wadcutters in the 357 mag that I can find, though there are some for the double based wadcutter, it stands to reason no acceptable loads were developed for this bullet style.

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Agreed. That is what this bit of research is all about, to see if there is a safe load or not.

uglydog said:

Putting "safe" though ineffective loads into a manual would probably negatively affect the reputation of the publication and ultimately affect their bottom line.

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Again, I concurre. I would also like to think that any given manual would post a cautionary note about HBWCs in a 357, if it has been proven to be unsafe, impractical, or dangerous. But, I have not found that info either.

uglydog said:

I am sorry you thought I called you a fool, I meant it to refer to the actions you were contemplating...

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I've re-read my post, and do not see where I indicated what I was contemplating. But allow me to clarify. I'm working up some loads for a HBWC in a 357 case. It is my hope, that I will find one. However, with the data I have now, my hopes are fading.

uglydog said:

...contact a couple of bullet and powder companies directly.

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I will contact them, but not until I have done enough research to be able to ask an informed question. And, unless I can find a powder that can fill more than 50%, it's not even worth asking, as I will already have my answer.

I am sure that you have heard the rule of thumb "get as close to 90% fill as you can". If I stuck to that, I'd have to throw out most of the data for "target" loads as those charges do not give a 90% fill. And so far, with this project, 53% is as close as I can come, and I don't like it.

Part of my point is that I've never heard what a lower limit would be. When does one start to think about a given charge being safe?

And that leads us back to my original question "At what point do you feel that there is not enough powder in the case to fill it?

I'll start. 75% is where I begin to worry.

What loading data sources are you using in your quest? I have looked at the several I have at my current disposal and every one of them that only lists a maximum load also has a admonishment to start at a given percentage of powder weight lower and work up. They all have that amount listed just before the load data under a large, bold print "Warning" heading along with other cautions. I'd guess we have different ideas as to what we find "interesting" as sections with those type of headings generally get my attention.

As for the percentage of case taken up by powder needed to be safe, that is immaterial if recommended published loads are used. These have been found to be safe and one only begins to get into trouble when they begin deviating from them. In the case of a non-published load, especially with one that has been around as long as the 357 mag and HBWCs, it is very likely that suitable loads have not been found and it makes more sense from a cost and practicality standpoint to not even mention it (or any other non-suitable load) than to make a mention of it in the book. After all, how many people ignore a wall every day of their lives but just have to touch it if a "wet Paint" sign is hanging on it ? After all, wadcutter bullets of any kind are generally made of rather soft lead (meaning little to no hardening agents compared to other bullet types) and do not respond very well to velocities much over 800 fps. Odds are this combination requires either an exact recipe with no allowed deviation if suitable results are to be found (something many are not capable of doing) or testing has shown one either gets too little pressure or inconsistent ballistics and too great of a risk of lodging a bullet in the bore or the next step is too high of velocity (but still safe pressures) for the bullet design and excessive leading of the barrel. Either of the last is not a desired result so it makes no sense to publish. As I alluded to in an earlier post, it is not just pressures that are looked at in devising loading data but consistency and suitability of purpose are also factors.

As to contacting powder, bullet, or other sources for data, it is a simple process. Just pick up the phone and call their information line and ask. If there are safe though maybe not widely suitable loads available, you will probably be given them. If you have specific components you want to use, call those manufacturers first or make sure to mention that desire in your discussion. One does not need to know a whole lot initially and
a discussion with a technician will often bring up many questions on its own that you can ask. These representatives have heard it all before and can often provide important insight that the typical person contemplating an idea or action would never piece together. They are pretty experienced in this area and it is not very likely a caller would have a question that would stump them, at least not for long.

Overall, the amount of space taken up in a case by the powder is not overly important if one sticks with the listed data. A heavy, but safe, drop of a ball powder might take up relatively little space in a case as it is a very dense powder while a very light load of a bulky powder can cause dangerous conditions though it takes up more space in the case. That is why powder weights are used with today's smokeless powders and not volume. Volume is listed occasionally but it is not an important factor otherwise everyone would use that info. One would also need to know what parameters are being used for determining the percentage requirements. If it is total case capacity, then even at 75% capacity it may be difficult to seat a wadcutter bullet as it sits so deeply into the case. Using net case capacity (after subtracting that space taken up by the bullet) would be more applicable but a bit more complicated to determine. That "90%" rule of thumb is one I've heard for "hunting" loads using bottlenecked cartridges and that was also using slower burn rate powders. I have heard it mentioned by a few writers but not why they chose it. The closest I've come was a mention by an influential writer decades ago who stated he did not like compressed loads. No other reason and I suspect that is the impetus for that rule of thumb today though I can't prove it. It also applied to the powder capacity (up to the base of the neck) and not overall case capacity. As you mentioned, "plinking" loads do not follow this rule and is one of the reasons volume is not used to determine safe loads. With straight walled cases such as revolver cartridges, I have frequently read mention of using loading data that allows one to easily see if a case has been double charged or not charged at all. Whether that meant a case overflowed if over charged or if it meant one that would be readily different than the others was not specified.

As for your question of "At what point do I feel there is not enough powder in a case to fill it?" I don't really care. As long as a published load is used I feel the percentage of powder volume is correct. For those combinations that I can't find published data, I simply call the manufacturers of the components I want to use and ask them for advice. If there is anything available they have told me and if not they told me that too and why.