Starting load is equal to max load?

[ScottRiqui]

I've noticed quite a few entries in the Lee manual where the starting load and max load are the same. As an example, with a .380 ACP 95 gr FMJ bullet, the entries for W231 and Unique both have starting loads that are the same as the max loads.

Does this really mean that I shouldn't go beyond the starting load, or does it just mean that the authors simply duplicated a "known safe" load without working it up themselves?

In the case of the W231 recipe, the resulting speed is 200 fps slower than some of the other powders listed for that bullet, with 6000 PSI lower pressure. That would lead me to believe that the "max" load isn't really the max, but I also know that increases in chamber pressure aren't always linear beyond a certain point.

 

[Don P]

Yes thats what it means do NOT EXCEED MAXIMUM LOAD.

In the case of the W231 recipe, the resulting speed is 200 fps slower than some of the other powders listed for that bullet, with 6000 PSI lower pressure. That would lead me to believe that the "max" load isn't really the max, but I also know that increases in chamber pressure aren't always linear beyond a certain point.

Do yourself a favor and follow the recipe. I can assure you you DO NOT know more than the folks that put all this load data together for us do.

 

[Jeff H]

In the case of the W231 recipe, the resulting speed is 200 fps slower than some of the other powders listed for that bullet,

Fast target powders are rarely give the highest velocity. That doesn't mean you aren't at a max load, it just means they guy doing the testing felt it was unwise to load that powder any hotter.

 

[ScottRiqui]

Do yourself a favor and follow the recipe. I can assure you you DO NOT know more than the folks that put all this load data together for us do.

Oh trust me - I have no interest in playing "junior chemist", and I'm not going to exceed the max listed in the recipe. But I still find it very curious that 3.2 gr of W231 is both the starting load AND the max load, even with a speed of only 860 fps and a pressure of only 15,000 PSI. That really doesn't sound like they worked up the load at all - that's why I was asking if some of the recipes in the Lee book are just copied from other sources without further experimentation.

In fact, of the fifteen loads listed for a 95 gn FMJ .380, almost half of them are the same way - the max load and the starting load are the same.

 

[Adamantium]

With those powders there is no risk of a squib if you reduce the max load by 10% and work up. I honestly wouldn't worry about it though. Just go with what they say and watch for pressure signs like normal.

Are these just target loads or are you looking for extra velocity?

 

[Jim Watson]

Dagnabbit, lost my work, starting over.

Lee does not "work up" loads. They simply reprint powder company data with identifying information other than powder and bullet weight stripped out. Hodgdon shows .380 95 gr Speer FMJ + 3.2 gr W231 = 884 fps @ 15,400 CUP
so that was probably Lee's source for that load, given just as "95 gr jacketed bullet."

Lee's starting load is whatever their powder dipper is rated for next less OR THE SAME AS the maximum. This is safe enough because their dippers are very conservatively rated and seldom deliver as much as the chart says.

Perhaps Hodgdon ran into some erratic results that SAAMI statistical procedures kept them from increasing loads up to the maximum of 17,000 CUP.
If you want to do "load shopping," Speer will take you to higher velocity (and pressure) with that weight bullet. But I don't favor that purely for bigger numbers. If you have reliable function, what is to be gained?

 

[ScottRiqui]

Agreed - there's no reason to risk it, and really nothing to be gained. I was only curious because I just started reloading .380 and I noticed that so many of the recipes were only a single value, rather than a range of charge weights.

If for whatever reason I wanted more speed than W231 can give me, I'll just use Power Pistol. But this is just going to be range ammo, so I'm not that concerned. I just made up 10 rounds with 3.2 gr of W231, 10 rounds with 4.2 gr of Unique, and then ten each of Power Pistol at 4.2, 4.5 and 4.7 gr. I'll see which one is the most accurate and stick with that.

 

[Jeff H]

Agreed - there's no reason to risk it, and really nothing to be gained. I was only curious because I just started reloading .380 and I noticed that so many of the recipes were only a single value, rather than a range of charge weights.

Read the whole manual. As noted, Lee just reproduces info that was published by other sources that actually did the testing. Companies like Alliant only publish the max but tell you in the text of the manual to download 10% and work up. This is listed on page 8 of their current manual. http://outdoorwriters.atk.com/resource_library/catalogs/AlliantPowderCatalog.pdf