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Discussion in 'Caliber Corner' started by glock20c10mm, Jan 15, 2010.
How much recoil would you have by just firing the powder charge?
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Very little, because the lack of a bullet would preclude the chamber pressure from rising.
I.E. the fire hose analogy.
I would also add that I am not a physics professor and had a very hard time with advanced mathematics.
Sooo any weighted bullet in front of that charge will give the same effect, yes?
Who is Duncan? Duncan McPherson? Never read his book.
I'm going on what I learned in high school physics and and freshman college physics.
That was for Doc.
Edited for content and civility: The difference in bullet weight MAY make a difference, but there are other factors as well, such as speed of acceleration. However, the gases that are pressing back on the cartridge case are the primary cause of felt recoil.
Think of the rocket engine analogy again.
The .40 has 35,000 cup of thrust.
The .357 has 40,000 cup of thrust.
That is not an entirely accurate representation, but you get the idea.
If you use a recoil calculator... Input the .45 load above with only 6.2 grains and .357sig with 12grns @ 1350 in the same weighted guns...
This doesn't account for all factors like you mentioned. I'm just trying to illistrate the role bullet weight plays in recoil. Types of powders matter a great deal aswell.
You are right, but it's the resisitance from the bullet being unwilling to move. A bullet that is twice as heavy should take four times the effort to begin moving. Where's GLOLT when you need him?
So why does the gun barely recoil before the bullet leaves the barrel?
Also, why did Glock find it necessary to reinforce the frames when they introduced the .357?
The recoil is "sharper" which is more damaging. The quicker energy is transferred the less time the plastic has to try and absorb it and transfer that to motion.
Edit: I'm not arguing, I'm debating. Too me this happens to be an enjoyable discussion. I will also like to use one of your analogies above if you don't mind continuing the debate.
If you watch slow motion photography of a revolver being fired, you will see that the bullet has already left the barrel before there is any significant movement of the gun. And in a revolver there is no moving barrel.
I know this already, brotha. You have two opposing forces, the bullet and the gun... obviously the little bullet will be on it's way much faster than the gun. If the gases alone were creating the recoil, blanks would have more of an effect in Hollywood.
Let's take your rocket anology:
Place the rockets over sand.
Have the same "thrust" for each.
Have one wiegh 1 ounce, the other 1 pound.
-Which one do you think will disturb more sand?
My basis for using the theory to my advantage comes from the basic understanding of the principal of the theory. Like I said, I have plenty of questions myself, not to mention a larger data set would be awesome. Either way I do believe the theory holds water to enough of an extent based on events aside from the theory for me to apply it in my choice of carry ammo. Got a problem with that?
You can do what you like; maybe it will save your life someday, maybe not. My problem is that Courtney hasn't proved this well enough to make recommendations for carry ammo, yet that is exactly what he's done. Better data is crucial and we have already discussed the difficulties in obtaining it. Haphazardly collected "street stop" data and anonymous goats are simply not sufficient.
Why would you think such a thing? What you say is absurd to say the least. You simply don't understand what it means for any data set to be statistically valid and I don't care to explain it to you. BTW, that is fact, not my opinion.
I understand exactly what constitutes a good data set in order for any statistics derived from it to be meaningful. My entire undergraduate degree was based around research design and statistics and I graduated with honors. What do I have to do, post a copy of my degree? In essence, Courtney is trying to say that a projectile with kinetic energy E has a probability of incapacitation X. Calculating that probability requires large sample sizes period. Flip a coin ten times and getting 7 heads does not mean the probability of heads is 70%. Flip the coin 100 or 1000 times gives a more accurate picture.
You can calculate the objective probability of a coin flip as 1:2. It is simply not possible to calculate the objective probability of incapacitation, hence we're stuck needing large sample sizes. End of story.
No, Dr. Courtney doesn't have to prove anything.
You're right; he doesn't need to do a thing. But if he personally wants his research to be more persuasive, he needs better data.
Besides, you already feel rubbed the wrong way by Dr. Courtney. At what point would he ever be done getting you to believe he ever did anything right? Beside the fact you said it would all have to be verified by a third party before you'ld believe it anyway.
I don't see a problem here. In the end it's about what it takes to be persuaded. Third party validation with better data would help a great deal.
--The science is in the ability of the research to withstand criticism. Period. <!-- END TEMPLATE: bbcode_quote -->
That's not always true. Like when someone wrongly preaches for or against anything because of the way it may/will take negative effect on their credebility in one way or another if they don't.
Who has credibility at stake? Any investigator's credibility rests on his ability to persuade. The methods exist to answer criticism. Scientific rigor is all about withstanding criticism. Otherwise we're back to anecdote and opinion.
As for you saying; "I'm not sure why you seem to think that anyone critical of the research is somehow not qualified to evaluate it..." I didn't, nor would I say such a thing, as it is not true. But yes, it is my opinion as it were.
Um, you're contradicting yourself here. Besides, the science isn't really all that difficult to understand. There's no point to getting into a pissing contest over credentials.
And in some cases it doesn't matter enough to worry about, like with the ATK workshop testing and results.
Actually I agree with you on this one. The data is presented in a manner that makes it seem objective. In terms of reliability I see no real need to replicate it.
Who cares? There are exceptions to every rule.
That's exactly why you should care. Why are there exceptions? What do they mean with regards to incapacitation from BPW. If the means of incapacitation is physiologic why would drugs or adrenalin make a difference? They shouldn't but they do.
It's not like the "shrug-it-off" standard is associated with anything close to a majority.
Gotta support that assertion with some good quality data, but that data has never been collected. I personally have no idea what the percentages are. I agree that it occurs in the minority of cases. Unless the dude is on PCP. And how would you know that in advance?
And why are you so stuck on TBI? Who cares, TBI or not, if it works toward quicker incapacitation reguardless the mechanism?
Um, because that's what Courtney is talking about? Either we have a physiologic mechanism or we're talking about...what? Shoot a guy and he drops. Why? That's the exact point of this entire body of research, Fackler and Courtney both included. How could you possibly miss this essential point?
It may be limited to a percentage basis, but if it works as much as expected, who cares? I'm not saying it does or doesn't within the expected parameters of the threory. Just saying.
It IS limited to a percentage basis. I do think the entire thing is worthy of further research. With better data the end the entire question of which caliber to choose could come down to a fairly simple test of marksmanship. If you can hit the COM of a target X percent of time with one caliber and Y percent another, you could crunch the numbers to see whether the probability of a miss with a larger caliber is counterbalanced by the increased probability of incapacitation to BPW. A lot of people shoot well with one caliber and poorly with another. Misses can't incapacitate regardless of caliber.
Drugs and adrenalin make a difference in what?
Incapacitation from being shot...If drugs or adrenalin greatly reduce the likelihood of incapacitation due to BPW it would greatly alter the calculation I mention above.
As is yours. Recoil is determined by the weight and velocity of the bullet, and the weight of the hand gun, NOT the pressure. Does the phrase, "equal and opposite reaction", ring a bell? The "rocket" and "firehose" effect has very little effect.
Nope! Way, WAY, wrong: equal and opposite reaction.
I shot a G-22 for the first time about two months ago. The ammo the owner brought to the range was 180-grain WWB. The recoil was much greater than with my G-32 using 125-grain ammo. I gave up any thought of buying a G-23 barrel for my Glock after that experience.
I was surprised because I had shot a couple of .40S&W pistols before (only a round or two) and didn't remember such a strong recoil from that caliber, but that's back when I only owned a .380ACP.
I guess since I unsubscribed to this thread some time ago I missed a lot of stuff, some predictable and some not so predictable.
BPW has stuck its nose under the edge of the tent? (Predictable )
I might as well say it again, since everyone else is repeating their favorite commentary ...
I think that further research into the BPW theory is probably going to continue to be required before it's readily established (wide spread within the scientific community) to have provided an explanation for some of the injuries being observed when people suffer gunshot wounds from typical handgun cartridges.
Further, once that point is reached where it's received wide spread acceptance, I wouldn't be surprised to see that even though the mechanism if more thoroughly understood, that it remains difficult to predict ...
Then, once the effect occurring can be better predicted, the totality of the effect and its potential influence when it comes to 'immediate incapacitation' on any particular human being is going to probably remain a bit difficult to predict.
In the meantime, I think I'll continue to place more emphasis on physical & mental preparation, training and reasonable attention to the selection and compatibility of the handguns & ammunition I commonly use for carry in anticipation of lawful defensive application in the worst of possible conditions.
Now, as to the actual v. felt recoil sidebar ...
I'll use the example of .40 S&W & .357SIG as has been previously discussed by company folks (including armorer instructors).
To put it simply, the fact that 2 cartridges may have similar pressures doesn't take into consideration how the pressures are actually achieved. Specifically, how quickly those pressures are reached.
When the Sig instructor was explaining why we might sometimes see peening on the sides of the barrel feed ramps of pistols chambered in .357SIG, and not in similar models chambered in .40 S&W, he explained it by saying that the rate of the pressure spike of the .357SIG produced force which slammed the bottom of the feed ramp downward against the frame's steel insert harder in the .357SIG than in the .40 S&W. It could sometimes cause the sides of the feed ramp to slightly deform outward after enough time.
It wasn't presented as something he said we'd necessarily see in all .357SIG pistols, but to check for it and address it if it ever reached a point where it appeared as though it might adversely interfere with normal functioning (requiring a file). He said this wasn't something typically seen in the pistols chambered in .40 S&W. Nothing was mentioned about how this mechanical difference connected to the rate of the different recoil forces might be perceived or experienced by the shooters. That can change from one user to the next and is a subjective perception.
Now, back to the original subject.
Some folks like the way they 'feel' and experience the felt recoil and recoil management of the .357SIG cartridge compared to others, such as the .40 S&W. Why can't that be fine for them?
Conversely, for those folks who do find the .357SIG to be fine for them, why can't it not be fine for those folks who find it's recoil and muzzle blast characteristics to be something they don't particularly like?
Might as well argue about the best hair color ...
The pendulum has been swinging a bit since the introduction of the .357SIG when it comes to trying to offer the best compromise in penetration and expansion, and then the whole 'bonded' bullet issue entered the fray.
There's enough in the way of caliber, bullet design and velocity thresholds and windows to go around to satisfy just about anyone, except maybe the most ardent caliber 'loyalist'.
Why not let things go and let everyone choose whatever floats their boat.
Those folks who are restricted for professional reasons to certain calibers & bullet designs can either deal with it by trying to change policy/procurement or else focus on training & practice to accomplish their tasks with the equipment at hand.
I tried to 'splain to him...
I saw that. I tried to make it simpler, but he's stuck in 'rocket and firehose' land.
For every action there is an equal and opposite reaction.
The force is equally distributed to the gun and the bullet at all times, from the instant of ignition to the moment when the bullet is no longer containing the gas pressure behind it (the instant it leaves the barrel). As soon as the gas seal is broken by the bullet leaving the barrel, the recoil force ends.
What you are seeing in slow-motion photography (when the gun moves after the bullet leaves the barrel) is the delayed application of the force on the gun due to the gun/shooter combination having more mass than the bullet.
If you clamp the gun into a solid structure of greater mass than the energy generated by the round being fired, the structure would not move at all.
Now, if you take and apply a load cell to measure the forces generated you'd see the steady increase in force applied up until the bullet leaves the barrel and then an instant loss of force.
A simpler way of testing this yourself is with a blowgun.
You blow and the instant the dart leaves the barrel the pressure required to "shoot" it is relieved.
There is no recoil force applied to the gun after the bullet has left the barrel... NONE.
There is no firehose/rocket effect... NONE.
Ehh bro, where the frick were you earlier?! Coulda used that pretty explanation alotta hours ago!