But the slide isn't back yet. The recoil pushes the slide back, compressing the spring / storing the energy. That energy isn't lost but when the spring uses that energy to move the slide forward isn't that energy directed away from the shooter?Originally Posted by X9VlmF8m
Regardless of the physics involved, at this point in my life I can run a 1000 round weekend class with a gen 3 G17 and have no issues. I run two boxes of ammo through a gen 3 G22 and I'd needing to ice bath my hands the next day and to some rehab working out. Back when I jacked myself up I was still a SWAT guy, easily cleaning the team PT test, and benching in the 350lb range. It sure wasn't a matter of physical conditioning being an issue.
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Joints/tendons/ligaments are funny and muscular strength clearly doesn't always tell the tale.
I shoot a lot of full power .40 at a time usually 2-300 rds, but am able to more than double that in a day without issue. The only time I hurt myself shooting was a 9mm, about 10 years ago. Back then I used to shoot 1000 rds a day, day in and day out for weeks on end, bookended by 3-500 rds almost every day. I was shooting upwards of 100,000 rds a year, and that included months of overseas deployments where I might have only fired a few magazines the whole deployment. No issues at all until I put CT grips on the 229. That made the gun just too fat, and I injured myself. Kind of like overdoing fatbar training.
Hackathorn warned me years ago that high volume shooting in any caliber would eventually lead to issues, and I don't doubt him at all. Just when those issues occur, and how they manifest, can vary quite a bit from person to person though.
I think part of my issue may be my build, and how I shoot. I don't have much give going, at all.
Pic of me with a Wilson 1911 for a Rich Grassi article, shooting Hornady 230gr +P, note gun shoots rather flat when I Mongo it;
I am the owner of Agile/Training and Consulting
www.agiletactical.com
Chuck makes his own finger grooves.
The pistol is a slingshot as the slide goes forward. We can use the same recoil energy calculator just with a powder charge of zero (because it is spring powered.) The slide assembly of a Browning Hi-Power is about 0.914 lb or 6400 grains and the frame with a half-empty magazine is 1.28 lb. If we assume 5 fps muzzle velocity (pun intended) then the recoil energy of the slide returning forward is 0.25 ft-lbf.
Since momentum is conserved we can figure the velocity of the firearm once the slide is in battery. Let's assume the shooter's grip causes the frame to attain a rearward velocity of 0.25 fps from the recoil of the slide returning to battery.
M1V1 + M2V2 = (M1 + M2)V3
V3 = (M1V1 + M2V2)/(M1 + M2)
V3 = (1.28 lb * -0.25 fps + 0.914 lb * 5 fps)/(1.28 lb + 0.914 lb) = 1.94 fps (forward)
Now we can compare the kinetic energy just before and after the slide returns to battery.
KE = 0.5 * M * V^2
KE (before) = 0.5 * 1.28 lb * (-0.25 fps)^2 + 0.5 * 0.914 lb * (5 fps)^2 = 0.356 ft-lbf
KE (after) = 0.5* (1.28 lb + 0.914 lb) * (1.94 fps)^2 = 0.128 ft-lbf
If the shooter doesn't want to drop the gun he has to absorb the energy of the now moving forward gun. My wild assumptions do return a 50% loss in kinetic energy released by the spring instead of the trivial amount I assumed earlier. The spring energy is only a fraction of the total energy and some of the lost energy will migrate to the shooter as heat or noise energy. As I still doubt that energy is the appropriate measure I'm going to quit here.
Put the math away!
I don't know about Jesus but Red Reddington does and that's enough for me!
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High volume is not as important as more often when it comes to firearms training. Same with physical training and ground fighting techniques. If you must deplete large volumes of high recoiling ammunition say for a weapons test, then it is important to bring in some cadets/coworkers/friends to spread the love around or spread the volume over many days. Too often group/instructor trainings are setup to accommodate large number of students on conflicting schedules. So, the training sessions are cramped into time constraints and so many rounds must be fired to achieve the end goals of the session. Personally, I feel that most students start to go downhill after about 2-3hrs, and 2-3 hundred rounds fired......but many instructors keep pushing the students well beyond that even though it becomes a matter of diminishing returns. We certainly don't PT or do DETAC beyond those attention and physical spans, yet for the sake of schedules we often do it for firearms.
Last edited by Hauptmann; 02-08-2016 at 03:03 PM.
9mm vs 40 debate. Jesus kill me now.
I don't have any cool stories but my agency (about 6,500 plain clothes and I would say 4-5k more uniform) conducted an extensive test between our duty 40 and 9mm ammo using all of the standard barrier testing. Overall, 9% performance difference between the 40 and the 9. That's not much. Along with theFBI, we now have a RFP out for a new 9mm handgun.
Stay safe.
Scott
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