Reconciling Different and Disparate Loading Information

Remember that any (and all) published load specifications are properly valid only for the exact components, fired through the test gun or barrel, at the temperature and humidity prevailing at the time of the test.

Do minor variations from any of those parameters really matter? "Probably" not, but they may. This is why we are always advised to start at the starting load and test a few rounds, then work up in charge weight while watching for signs of problems. Starting with Lehigh's own data for Lehigh bullets is a good idea, but IMHO you shouldn't just load up a couple of hundred of them and hand them to your friend without first testing a couple of them in the gun or guns in which they will be used.
 
Based on what you've said...and the data on Lehigh's website, I would say you are probably loading a little light. I doubt the load is light enough to cause a squib...especially since the projectile material is likely much less expansile than lead. My main concern would be that the load (being lightly charged) might not cycle the action...in which case, I would go on up to the Lehigh-recommended starting load and COL and go from there.

I share others' concern that you probably should load and test fire them yourself, rather than load them and send you buddy off to test them without you.
 
robhic said:
The FMJ bullet I used to load the Lehigh bullet was pretty much the same length and the shank portion about even for the Lehigh and the FMJ bullet I used for comparison.
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You seem have made in incorrect assumption that the ungrooved solid copper and an FMJ will behave similarly in the gun because the coefficient of friction between steel and copper will be the same. The FMJ is actually much more malleable. If you place one on an anvil and smack it hard with a hammer, it will deform a lot. Do the same with the solid and it will deform a lot less. The same thing applies when you force the bullet through the throat of the barrel. The lands have a much easier time squeezing the FMJ down to "engrave" it with rifling marks. It takes more force to engrave the solid. It is this force, and not copper-on-steel friction that does the most to determine how high pressure gets. By its greater resistance to being engraved, the solid has to have more pressure behind it before it is pushed into the bore. When you build more pressure while the bullet is still mostly in the case, the powder burns faster and the bullet is subsequently not as far down the barrel when the pressure peaks, and therefore it peaks in a smaller space, raising the pressure value over what you get when the bullet is easier to push into the bore.

Your loads will probably shoot, but have your friend be careful with them that a bullet doesn't get stuck in the bore. It is unlikely, but if he doesn't see a hole in paper, he should check the bore before firing again, as shooting a bullet into a stuck bullet will likely break the gun and maybe the shooter.
 
Thanks for the added information/explanation, Uncle Nick. I must say that this whole exercise had been a learning experience for me. Thanks to all!!!
 
When we have discussions of this nature... there are countless numbers of us who all get the opportunity to learn, certainly including folks that aren’t even posting .

I still believe that TFL Forums host the finest handloading discussions on the web.
 
Sevens said:
When we have discussions of this nature... there are countless numbers of us who all get the opportunity to learn, certainly including folks that aren’t even posting .

I still believe that TFL Forums host the finest handloading discussions on the web.
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This is why I tend to enjoy how threads will drift from the subject, never know what you’ll learn.
 
robhic said:
I hear what you're saying and appreciate the info. I DO know (unfortunately) how as little as .001gn can make a noticeable difference.
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I don't think one thousandth of a grain of powder difference matters. You'll need to remove one tenth of a powder particle to change weight that small.

A two tenths grain spread is good enough for 99% of all accuracy objectives.
 
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