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Discussion in 'Handguns' started by zaraster, Jun 6, 2008.
Slow Motion Pistol Fire
That was very cool, thanks for posting.
I just had a revelation. People contend that bore axis is a primary factorization in the guns perceived recoil because of leverage. However I noticed that when the gun is fired the slide's rapid deacceleration point is when the true recoil begins. When the slide is in travel and the spring rate is doubling there isn't an acceleration in movement. Overall KE is mitigated through the reduced dV. Bore axis itself is a gross generalization of the weapons design, since the actual pinned bearing is the location of the slide stop. The location of the slide stop itself is where the force is transfered, and that in relation to the centerline of the counter force (the grip) is what gives the torque moment. Mounting the barrel lower has the potential to lower the frame stop, but is limited by ergonomic design.
From that it appears that an ultra light slide and a maximum travel distance in the spring is optimal to reduce recoil. The effective rate of the spring would be best left at a higher point to reduce peak KE moment, and rather dissipate it over a greater range of time. Then again a heavier slide would tend to expel greater energy down the barrel rather than into your hand. Hmm...
It also appears that the 1911 would be better suited with a deeper bushing interface with the guide rod. There was significant guide rod flexure relative to the chassis. Giving the guide rod stability would help reduce binding moment in the spring. As would reducing the actual coil pre-load in 1911's. Hence the reason HK utilizes a flat coil spring in it's guns; maximum travel before bind causes infinite rate.
Put the science book down. We are all layman here.
One thing to consider is the fact that the gun needs to properly lock up, slide needs to travel fully to the rear to properly eject the spent round as well as to properly slam the new round forward. To give you an example, that Sprinco recoil reducer (it's a dual spring guide rod for those that aren't aware of them) operates on a somewhat similar principle to what you are describing. The smaller inner spring is considerably stiffer and begins it's compression near the rear of the slide's travel. So basically the second stage is the inner spring, and it starts compressing when the slide gets close to the end of it's travel. Heres the BIG problem I found with that. From what I've seen there can be sort of a "timing" issue in altering the nature of the rearmost travel of the slide. With the Sprinco unit, there was a definite effect, so much so that locking the slide back manually actually took some effort. Basically I could pull the slide back as usual and would be a few millimeters to maybe as large as a quarter of an inch away from the slide stop notch and then spring tension from the second stage spring kicked in at that point and I would have to physically force the slide back with quite a bit more force than the stock guide rod and single spring setup. In my case, the dual recoil spring assembly was on my P220. This unit decreased reliability with JHP's by a full 100%. I had FTF's and FTE's every 1 or 2 rounds. Afterwards, I painstakingly went through ~200rds of various brands of JHP's. After doing back to back testing with the recoil reducer and the stock guide rod/spring setup, I came to the conclusion that the dual spring recoil reducer was negatively effecting the timing and lock up of the gun. I'm just a layman but, from what I understand, that rearmost travel of the slide right before and during lockup is the most important part of the slide's travel. Not quite enough travel and you have serious feeding/extraction issues (exactly what I had with the Sprinco and JHP's). Considering that most conventional handguns (at least those I know of) operate on a Browning tilting barrel design, and are designed to "lock up", and because handguns in general have limited space for a recoil spring, honestly I don't think there is much you can improve on. There are a few manufacturers out there using dual recoil spring assemblies on production guns (H&K, Walther, etc etc) and they seem to do just fine, so in principle the dual recoil spring method can work. I just think with aftermarket units, they might not be as R&D'd as a firearms manufacturer would, so the effect on timing and lockup is probably less than optimal.
One other thing. That drastic deceleration of the slide reaching it's rear most travel and the gun locking up? Well, also keep in mind that if you "dissipate" the shock by attenuating it over a longer distance as you've described, that is also going to effect extraction and feeding. You would likely have weaker extraction and feeding. Feeding may not be as much of an issue with FMJ's, but at the least extraction would be affected as you wouldn't have as sharp of a lockup to fling the spent shell out.
I think this is entirely too much discussion of theoretical physics on what is relatively simple. Just Hulk Hogan deathgrip that sumamab*bitch and shoot it, that will decrease muzzle flip a bit! That or buy a 9mm or .22lr handgun. lol
Here are some excellent high speed videos:
There are 4 vids and they are at the bottom of the page. I in no way endorse the C.A.R system, and personally think it is pretty friggin ridiculous (dude has been watching too many movies like Die Hard). I just posted it because I think the vids are neat.
What I said has more to do with the design and construction of the gun rather than modifying it. When you modify the gun you are restrained by it's physical limitations. I haven't seen much that would really reduce recoil on the gun apart from the usual suspects.
The rapid de-acceleration just allows the cartridge to pop outwards. You could do the same with a cam on the mechanism as the slide travels back, or even using combustion gas.
The slamming of the new round comes from the springs potential energy and as such doesn't require anything beyond the compression of the spring.
I need a 24" long slide 1911 chambered in .308 ... that'd be awesome.
Not quite, several ME and MDE here, including myself
Hehe. I like simplifying things, that's why I'll never be engineer material.
Thanks for posting.
More slomo footage as seen in the OP by the same guy can be seen on YouTube...