Some companies only give 1 number and suggest a starting load of 10% less. Starting 10% lower than a recommended starting load might work, but would be a kind of anemic.
Originally Posted by Shadow9mm View Post
I always understand you should start 10% below max. Or use the start data if available. Maybe that is what they are saying.
Ages ago, when I began handloading, the standard recommendation was to start (approx) 10% BELOW STARTING LOAD. NOT 10% below MAX, you started BELOW the listed starting load. ALWAYS! (unless there was a specific warning not to such as may be found with certain slow powders).
Yes, it may not "work" (meaning it might not cycle your semi auto), and yes, 10% below starting load is kind of anemic. That's NOT the point.
The point is to take a load that ought to be safe, reduce it a bit just to be super careful, then test fire a few, to be certain it is safe, in YOUR gun. Then, you work up to the starting load and shoot some at that level, again to ensure things are ok in your gun with your components, before moving up in steps to full power (max) level loads.
You don't start at max, or even 10% under max because you don't know if that will be safe in your gun. Sure, it probably will be, but you can't KNOW until you test and blowing up your gun because you thought it was ok when it wasn't, and proper testing would have stopped you before you got there isn't a good thing.
I know, its slow, its frustrating, its a "waste" of bullets and components...BUT
There is a bell curve to these things. The majority are in the middle but there are always a few at each end. And if YOUR GUN happens to be the rare one at one end of the curve, what is a safe starting load could be an unsafe overpressure load in YOUR GUN.
I've seen guns that had sticky extraction, and cratered primers with factory loads and even some that did it was handloading starting loads which were even lower. And those guns were not mechanically deficient or broken, and were, technically "in spec".
so, for maximum safety, we start low, actually starting a little bit below "Low" and shoot a few. When they're safe, we step up to "low" and repeat the process until we get the desired velocity level.
we may get pressure signs and have to stop short of the data's listed max loads, too. And, I've seen guns where people loaded to well over listed max levels with no signs of excess pressure at all. Every gun and load combination is different. And in that difference is the
potential to be radically different.
No one knows until it is tested by actual firing. No table of data fired in someone else's gun can tell you. No computer program can tell you.
Only test firing that combination of components in your gun can tell you.
Change anything, you MIGHT change everything enough to move from a safe level to an unsafe one. Again, live fire testing is the only way to know, which is also why we say drop down when you change components then work your way back up.
Sure, 99.9something % of the time its all good but the one time its not good it could be really bad, and really bad has cost people good guns, some fingers and even some eyes. A few have even lost more.
SO, go ahead and start where you think you must, start high to "save time" and you could very well have a lifetime of enjoyable and safe shooting. but, if the stars line up just the wrong way even once, you might regret it for a long time.
I'll be honest, I don't always start at the very bottom especially if most of what I'm using is something known and proven to me. But I never start at the top (or just under) when dealing with complete unknowns.
So far, I've always "gotten away with it", but its a risk, one I might be willing to take, but not one I will recommend to others.