Recommended minimum with a 38 Special 158gr LFN is 4.2gr.
I went all the way down to 2.8gr and although it was great to shoot, I got about 2 rounds out of 50 that produced significantly less power.
I can go back up to around 3.6gr again but would rather try to get this load working.
Primers are Federal SP and the gun is tuned so that they only just go off. I was speculating if the force the hammer hits the primer habd anything to do with the power of the primer ignition, ie a harder hit would produce a more powerfull flame. Anyone know the answer to that?
cal44walker
My Good Cal44walker -
Smokeless powder can be very dangerous when one strays from the powder manual.
Erratic ignitiion and erratic pressures are BAD SIGNS. You have deliberately gone below 70% of the recommended minimum.
That minimum was carefully calculated by engineers and scientists who have equipment available for measuring pressure peaks, instantaneous spikes, pressure waves and speed of wavefronts, and the stresses they cause to firearms, as well as methods of examining and testing for metal fatigue, stresses, fractures, etc.; not to mention the background in structural materials, mathematics, and physics that make our mere mortal brains spin.
The pressure curve of Smokeless powder is highly dependant on numerous variables, not the least of which are temperature and pressure.
As the amount of powder, the type of primer and the temperature of the ignitor vary, the pressure curves in the variable pressure vessel that is comprised of the the cartridge, cylinder, barrel, and bullet can change drastically and rapidly.
when you go above or below the recomended max or min in the powder manuals, you are entering a twilight zone of intederminate chemical reactions and unpredictable results.
In other words, all bets are off, and no one will guarentee anything.
please read this thread,
http://www.cascity.com/forumhall/index.php/topic,46828.msg580100.html#msg580100and contact trailrider who clearly knows wherof he speaks.
You have already seen that you are getting what appear to be "squibs" which appear to be a drop in pressure without (seemingly) changing the load. In actuallity, you may be dropping .05 gr more or less, or crimping one pound more or less harder, or seating the bullet .05" more or less "deeper" or even have a change in temperature... ... just these four things alone can change the dynamics of the "pressure vessel system" and once you enter the "twilight zone" the changes can cause a pressure can drop - or a pressure spike.
You may get a pop, or you may get a KABOOM, or you may get a bullet stuck in the barrel
No one can tell you which way it will go, or when, or why. That's why it's referred to as "indeterminate".
You have speculated that by varying the force of the hammer, you "may" be producing a cooler primer flame? That can
only be determined with lab equipment most of us do not have, and further You need to understand that a cooler primer flame
is yet another variable that MAY NOT BE DESIRABLE!.
Do not take this wrong, but If you insist on changing your loads so far from official recomendations, please let us know where you are shooting so we can avoid going there. I personally do not tolerate such unsafe practices.
yhs
prof marvel
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