Interesting. It looks worse on paper, I guess. In the G29 example I've been working off of, the slide velocity is around 27.3fps, which is 14.2 ft-lbs of slide energy max as the bullet leaves the barrel. I imagined that would hurt more due to the suddenness of it, but I guess not. Also, thanks for posting your spring data. Any Cal, that video is great. Thanks! RMM, no problem. You are not being argumentative at all. I certainly don't claim to have all the answers. I learn new things here from other people's experience all the time. Probably everyone here could write a short book on gun lore. Some things that get repeated and passed along are true, some are partially true, and some are totally bogus. But I also believe that every observation has an explanation, we just don't always have enough info at the time to be able to explain it. I just want to better my understanding, and try to get to the truth if it's possible. Sometimes the best we can do is to offer theories of why things are the way they are, but if there's ever an opportunity to nail something down where the theoretical supports the empirical, or vice versa, then I think we're making progress. I'm going to clean up my spreadsheet and make it available to anyone who wants to look it over. If I made mistakes on any of my calculations or assumptions, I would rather have it discovered sooner than later, so I'm not adding something untrue to the gun lore. I already know that my timing data for unlocking may be incorrect, since I used constant acceleration, but there seems to be a lot of margin built into the G29 design to prevent that from happening, even if my numbers are off a little. I have some pressure curves that I hope to fit to the acceleration of the bullet and the slide, and see how that affects the timing. I also have some info that I found on the gas jet effect, and I want to incorporate that, too. It would also be nice to model the slide speed when it hits the physical stop, and when it returns to full battery, but that's going to take some calculus, and I'm a little bit too far out of school for that right now. I may have to pull out a text book to figure that one out. Anyway, when I get some time I'll try to get this sorted out and explain the math as best as I can. It's really not all that complicated. I've already kind of hijacked deadandgone's thread, so maybe I'll start another one. It's a hot topic that will probably cause a lot more debate. BTW deadandgone, that "Glock tattoo" is really cool! I can see you showing it to your grand kids one day..."and this one is from when my G29 exploded in my hand while I was shooting some Swampfox..."