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Touche, it would be the mass of the gas and not the volume specifically. But obviously volume is related to mass when dealing with gas at specific pressures.
So, your graph there seems to be interesting but not to the point. I would chart grains of powder to energy of the bullet and see what that shows. I think you would get with that graph an actual "comp effectiveness" metric.
However, your graph does show one interesting thing. The energy is of the bullet. So if the energy goes up, more compensation is needed because the energy of the bullet is equal to the recoil energy, give or take a few issues not related to revolvers.
Assuming "it" is the comp, it needs some combination of volume/mass because the idea is the volume of air escaping the comp creates the downward force above the barrel to push it down.
Imagine a scuba tank filled with CO2 and a small CO2 canister both loaded to 1000 PSI. Now imagine cutting the top off both (assuming the resulting hole is proportional to the volume/mass of gas) at the same time. Which one has more force?
It's the mass of the gas counteracting the mass of the bullet.
Why do I need to counteract the mass of the bullet? Why is the mass of the bullet relevant beyond how it affects the pressure of the gas? The bullet didn't do anything. The gas expanded and acted on the bullet. The gas pushes the bullet forward and the gun (roughly) backward.
I get the idea of how a comp works. Your explanation and Slowdive's drawing both explain the concept of a comp quite well, but I already understand that. I want to know why it doesn't work as well with heavier bullets. Jim said that as I decrease powder and increase the bullet weight, the comp's effectiveness drops. As I understand things, the energy of the gas is what works the comp (more energy = more recoil but also more energy to work the comp). My first graph shows that as I decrease powder and increase bullet weight the energy goes up, so why don't I just drive the comp harder to compensate for the heavier recoil?
It's the mass of the gas counteracting the mass of the bullet.
Why do I need to counteract the mass of the bullet? Why is the mass of the bullet relevant beyond how it affects the pressure of the gas? The bullet didn't do anything. The gas expanded and acted on the bullet. The gas pushes the bullet forward and the gun (roughly) backward. In a handgun, the backward motion also gets translated to muzzle flip because of the geometries involved. The comp reroutes the gas (once it's done most if not all of its work on the bullet) to push the gun forward/down depending on the comp. As I understand it the gas is compensating for the gas, not the bullet.
Just to be clear, I don't doubt what you guys are saying, I'm just trying to make sense of this. Thank you!
In most guns the barrel is high center of the handle and so the path the gun takes in recoil, while initially straight back, ends up causing rotation of the gun because the hands of the shooter cause deflection. A comp negates the force of this rotation. .
One poster above mentioned a list of guns prone to bump fire. Where is such a list? And how does one see it?
Why do I need to counteract the mass of the bullet? Why is the mass of the bullet relevant beyond how it affects the pressure of the gas? The bullet didn't do anything.
The problem is you are reading Jim's statement too literally. He simplified it but in reality, a comp (like what's found on the S&W 500*) is not counteracting the recoil of the bullet (or "the gas is compensating for the gas") but counteracting the flip of the barrel. There is some italian made revolver they manufacture and market as recoil free but in reality it is muzzle flip free. They place the barrel in line with the plane of the gun's natural recoil path when in human hands. As a result it puts the recoil straight back and eliminates the barrel flip.
The weight of the bullet has everything to do with recoil. Your body has to resist the force of the bullet moving down the barrel. Heavier bullets generate more felt recoil. It's not the gas, and it's not the pressure.
Let's take an extreme example...
Let's say you were to make a styrofoam bullet for a .500, and use an explosive propellant that was able to generate the 60,000 PSI or so that a .500 round can produce fast enough so that it reached full pressure while the bullet was still in the barrel. You would feel almost no recoil because the gas pressure isn't pushing on anything for which your body needs to provide 'backing'.
On the other hand, if you were to take a .500 bullet and connect it with a solid rod to an engine block outside of the barrel (to simulate a really heavy bullet), and selected a powder that burned slow enough so that it wouldn't generate more than 60K PSI while the 'bullet' was still in the barrel, the recoil would literally knock you over.
If we took Jim's loads to a comp guy, he could design a comp that would work well for that load.
I'm kind of following, but I counter with a rocket engine. If it's all about the bullet, then why does a rocket engine work?
This makes sense to me - particularly since .50 BMGs and even tanks have comps...
He won't be able to do a thing because no matter how you direct it, 25gr of gas isn't going counteract the recoil generated by a 700gr bullet.
The weight of the bullet has everything to do with recoil. Your body has to resist the force of the bullet moving down the barrel. Heavier bullets generate more felt recoil. It's not the gas, and it's not the pressure.
Let's take an extreme example...
Let's say you were to make a styrofoam bullet for a .500, and use an explosive propellant that was able to generate the 60,000 PSI or so that a .500 round can produce fast enough so that it reached full pressure while the bullet was still in the barrel. You would feel almost no recoil because the gas pressure isn't pushing on anything for which your body needs to provide 'backing'.
On the other hand, if you were to take a .500 bullet and connect it with a solid rod to an engine block outside of the barrel (to simulate a really heavy bullet), and selected a powder that burned slow enough so that it wouldn't generate more than 60K PSI while the 'bullet' was still in the barrel, the recoil would literally knock you over.
It's the mass of the gas counteracting the mass of the bullet.
You kept referencing the bullet and I wasn't making the jump from the bullet's movement to the force generated by the movement. I couldn't understand why we'd need to turn the bullet around...I was pretty sure that'd piss of the RO's something fierce. Thanks for sticking around until it clicked for me.He won't be able to do a thing because no matter how you direct it, 25gr of gas isn't going counteract the recoil generated by a 700gr bullet.
You're not going to turn around a 700gr rocket with 25gr of gas.
You guys are wicked smaht but my head hurts now.
You guys are wicked smaht but my head hurts now.
Physics 101 class on sunday is hard.
So the bullet & gas start moving and whatever m*v they have is matched by the rearward m*v of the gun and shooter. When the bullet leaves the muzzle, we have chance to capture the gas and use it to counteract the rearward m*v that we perceive as recoil/muzzle flip. If we capture the gas like this, then it stops contributing to the recoil and the recoil is equal to the m*v of the bullet. But since v(bullet) and v(gas) are nearly equal, the m(gas) has to approach m(bullet) in order for the momentums to be nearly equal and for us to have a force to counter recoil with.
Um, I'll just be over here shooting
So if porting will do nothing, how about converting it single action?
Note to self, stick with your Model 29 .44 magnum.....
And another one:
There's no need for me to do that because I know how to shoot it.
Yeah, at the range it is relatively easy to control it if you know the gun. I tend to use these sort of things hunting, and in the field...things happen faster. You might get a shot off and get a little sloppy with your grip.
The downside would be, if a grizzly jumped you, you might not have the chance to cock a single action, but might get a shot off with a double action. I have heard tales of hunters opening their lodge door and a griz immediatly is on them. On the other hand, you would not want to double tap when you are deep in the woods!
As far as porting, I shoot a .454 with 300 grain (yeah it is not the 700 this guy was using) and it never pulls up like this gun did. The reason I assumed was that there are 8 ports drilled pointing straight up at the end of the barrel (4 on either side of the sight blade). It makes it loud as hell, but easier to control.
I think it's one of those things where you you've got to try it, and if you're comfortable with it, then you can use it in the field, if not; downsize. I don't find it hard to control even with the heavy bullets, but I've got a lot of time with it. With that said, I don't think "quick follow up shot" when I think about the .500.
The .500 is a lot different than a .454. I have a .460 (which is just a longer .454) and nothing I've ever shot out of it kicks like a stout .500 load.
How would you compare the perceived recoil to say a scandium j-frame 357?