Originally Posted by RMM
That said, how do we explain the extreme velocity spread that many have reported when shooting high powered ammo with the stock spring that is significantly reduced when switching to an aftermarket 22+ pound spring?
If it is true that running an aftermarket spring greatly reduces velocity spreads when shooting high powered ammo, then we could reasonably infer that the barrel is staying locked up for a longer period of time before unlocking.
That would then lead us to ask how this could happen, in spite of the mathematical evidence we have been shown to the contrary? I would postulate that either: (1) there are significant variables that we are not accounting for; or (2) there are variables that have not been correctly represented.
RMM, I can't give any explanation as to why this is true. The bullet should be out of the barrel before any significant difference in spring weight plays into it. In any case, the mass of the slide and barrel should create almost 400 times more resisting force due to acceleration from the initial recoil force than the spring does.
I have done most of my load work with a G20 and 22lb spring, so maybe next time I'm at the range with my chrono, I'll try the stock 17 lb spring and see how the data compares. Was the data all taken on the same day with the same ammo, with every powder charge hand weighed, consistent reloading technique with attention to details, and measured over the same chrono?
The other thing I can't explain is that some people have insisted that they get glock smiles with lighter springs and not with heavier springs, using the same ammo. If that's true then there is something definitely wrong with my basic assumptions. We probably need some time to see whether all of this holds water or not. I'm pretty sure it will.