Steve Schwartz, your expertise and insight would be greatly appreciated
in dealing with the following questions. 1) Is the recoil component of firing the free pistol instantaneous? Does the backward motion of the pistol begin as the bullet leaves the brass casing? 2) Is there an upward vector to recoil that causes the barrel to elevate slightly or is the upward motion an artifact of being at the end of a living arm? 3) Does a compensator really prevent the barrel from elevating or is the bullet out of the barrel before the following gases escape through the compensator ports and dampen the movements?
Elliott[/quote]
morini free pistol compensator
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Steve Swartz
Elliot:
I might not be able to answer your questions "authoritatively" but I'll offer my opinions. Others may disagree . . .
1) Recoil is pretty much instantaneous; as soon as the mass of the bullet begins moving down the barrel an "equal and opposite force" pushes along the bore centerline.
2) The resisitng force of the hand; and the center of mass of the hand/gun system is below the centerline of the bore. Therefore you have a backwards force above the "pivot point" which causes the rotational movement (muzzle rotates upwards). Also- there is a rotational component induced as the escaping gasses blow out of hte end of hte muzzle. This enhances/adds to the rotational effect.
3) The compensator allows pressurized gas to escape the muzzle end of the firearm before (or very slightly after) thne bullet leaves the muzzle. This escaping gas is directed above and away from the muzzle, resulting in a counteracting force. The net effect of the compensator is to pretty much eliminate the "gas effect" of rotation; and results in a "felt" reduction of the momentum effect of the bullet mass moving down the bore. The compensator does not "compensate" until *after* the momentum factor is pretty much completely delivered; but the typical shooter wouldn't notice.
A compensator is most effective when used in conjunction with a small, light bullet being pushed by a large amount of high pressure gas. Undrer these conditions, the "gas effect" of recoil is much more significant than the "momentum effect" and is effectively dampened by a compensator. Conversely, a lower pressure, high mass round would see very little compensation.
For a typical Free Pistol the compensators curently in use have very little real affect on recoil. However, they can improve accuracy (directly observed in some cases) and will most likely reduce *perceived* recoil.
However, the accuracy effect differs widely between the same model of gun/ammo apparently. The same make/model of pistol will apparently either be more- or less- accurate with the addition of a compsensator depending on serial numb er and ammo used.
"Your Mileage May Vary."
Steve
I might not be able to answer your questions "authoritatively" but I'll offer my opinions. Others may disagree . . .
1) Recoil is pretty much instantaneous; as soon as the mass of the bullet begins moving down the barrel an "equal and opposite force" pushes along the bore centerline.
2) The resisitng force of the hand; and the center of mass of the hand/gun system is below the centerline of the bore. Therefore you have a backwards force above the "pivot point" which causes the rotational movement (muzzle rotates upwards). Also- there is a rotational component induced as the escaping gasses blow out of hte end of hte muzzle. This enhances/adds to the rotational effect.
3) The compensator allows pressurized gas to escape the muzzle end of the firearm before (or very slightly after) thne bullet leaves the muzzle. This escaping gas is directed above and away from the muzzle, resulting in a counteracting force. The net effect of the compensator is to pretty much eliminate the "gas effect" of rotation; and results in a "felt" reduction of the momentum effect of the bullet mass moving down the bore. The compensator does not "compensate" until *after* the momentum factor is pretty much completely delivered; but the typical shooter wouldn't notice.
A compensator is most effective when used in conjunction with a small, light bullet being pushed by a large amount of high pressure gas. Undrer these conditions, the "gas effect" of recoil is much more significant than the "momentum effect" and is effectively dampened by a compensator. Conversely, a lower pressure, high mass round would see very little compensation.
For a typical Free Pistol the compensators curently in use have very little real affect on recoil. However, they can improve accuracy (directly observed in some cases) and will most likely reduce *perceived* recoil.
However, the accuracy effect differs widely between the same model of gun/ammo apparently. The same make/model of pistol will apparently either be more- or less- accurate with the addition of a compsensator depending on serial numb er and ammo used.
"Your Mileage May Vary."
Steve
Rumor?
Once upon a time a heard something about the compensator stripping away the gases that continue to accerate the bulet, and hance push the bullet even after it leaves the barrel. I have heard rumor that some barrel manufacturers taper the muzzle slightly, rather than cutting the end of the muzzle square, to allow these gases to move away from the bullet as it leaves the barrel.
Just rumor
Just rumor
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Steve Swartz
Great point Pete. You are absolutely correct!
"Back in the old days" when these things were studied extensively (by the "government" primarily) the effect of the exiting gasses on the base of the bullet at the moment of exit was determined to be a factor in the precision ("accuracy") of ammunition. This was pronounced for high velocity rifle ammo with relatively narrow, long, light weight bullets being pushed at high velocity with high pressure. Less so for pistol ammunition used in pistols (of any type) simply because so many other factors were so large that the muzzle upset phenomenon was kind of hidden in among other factors.
I haven't read any more recent stuff on this so it may have become more important as the other factors have been successfully attacked and reduced; that would make sense but I don't know for sure.
So we now have two main and one secondary effect of compensation:
1) Reduce rotational force from gas effect (main);
2) Reduce bullet base upset effect from gas effect (main);
3) Reduce felt recoil from gas effect (secondary).
Hey Pete maybe that's why accuracy improvements have been noted on some model of firearms . . . !?
[side note: I think pretty much all muzzles are countersunk to a certain degree; ditto for bullet bases being "rounded off." Coiuntersunk bores in combination with rounded bases would tend to reduce the bullet base upset effect from escaping gasses; not sure how much.]
Steve
"Back in the old days" when these things were studied extensively (by the "government" primarily) the effect of the exiting gasses on the base of the bullet at the moment of exit was determined to be a factor in the precision ("accuracy") of ammunition. This was pronounced for high velocity rifle ammo with relatively narrow, long, light weight bullets being pushed at high velocity with high pressure. Less so for pistol ammunition used in pistols (of any type) simply because so many other factors were so large that the muzzle upset phenomenon was kind of hidden in among other factors.
I haven't read any more recent stuff on this so it may have become more important as the other factors have been successfully attacked and reduced; that would make sense but I don't know for sure.
So we now have two main and one secondary effect of compensation:
1) Reduce rotational force from gas effect (main);
2) Reduce bullet base upset effect from gas effect (main);
3) Reduce felt recoil from gas effect (secondary).
Hey Pete maybe that's why accuracy improvements have been noted on some model of firearms . . . !?
[side note: I think pretty much all muzzles are countersunk to a certain degree; ditto for bullet bases being "rounded off." Coiuntersunk bores in combination with rounded bases would tend to reduce the bullet base upset effect from escaping gasses; not sure how much.]
Steve
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Ed Hall
Hello everyone,
If I might add, there appears to be a concensus for the coutersink (crown) for certain arms, such as 11 degrees being optimum for gun X, etc. I think another important aspect is that a countersink provides more protection from damage.
I would also like to comment on the rotational force from recoil described earlier in the thread. Depending on the rotational forces vs. muzzle velocities, slower ammunition can actually print higher than faster ammunition. This seems quite counter-intuitive...
I'm sure there has been some study on it, but compensation ports added prior to the end of the barrel could aid in keeping the barrel oriented to a certain point, but what effect would this have on accuracy?
Here's an idea from my thought processes: Perhaps the optimum would be a channel from the chamber to the muzzle that could vent a portion of the gas to the muzzle before the bullet got there. In fact, if designed properly, the raise in pressure could follow the increase in bullet velocity down the barrel. Compensation occurs almost simultaneously as recoil is initiated and even torque due to rifling could be offset. I wonder if anyone is already working (or has worked) in this area...
Take Care,
Ed Hall
http://www.airforceshooting.org/
http://www.starreloaders.com/edhall/
If I might add, there appears to be a concensus for the coutersink (crown) for certain arms, such as 11 degrees being optimum for gun X, etc. I think another important aspect is that a countersink provides more protection from damage.
I would also like to comment on the rotational force from recoil described earlier in the thread. Depending on the rotational forces vs. muzzle velocities, slower ammunition can actually print higher than faster ammunition. This seems quite counter-intuitive...
I'm sure there has been some study on it, but compensation ports added prior to the end of the barrel could aid in keeping the barrel oriented to a certain point, but what effect would this have on accuracy?
Here's an idea from my thought processes: Perhaps the optimum would be a channel from the chamber to the muzzle that could vent a portion of the gas to the muzzle before the bullet got there. In fact, if designed properly, the raise in pressure could follow the increase in bullet velocity down the barrel. Compensation occurs almost simultaneously as recoil is initiated and even torque due to rifling could be offset. I wonder if anyone is already working (or has worked) in this area...
Take Care,
Ed Hall
http://www.airforceshooting.org/
http://www.starreloaders.com/edhall/
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elliott
morini free pistol compensator
Steven, Pete S and Ed,
Thank you for your input. It was enlightening. Steve, I didn't realize the center of mass of the pistol/hand being below the barrel would cause the muzzle to rise. The compensator is almost six inches long and weighs at least 3 ounces. When I used it, I noticed two effects. One, the sound of the blast seemed to be slightly muted, the "crack" not so loud. Also, the tone of the "crack" was lower on a musical scale. Second, I personally noticed a reduction in the pistol movement on firing. Whether this was due to the effect of the compensator on the gases or just the added weight to the end of the barrel, I do believe there was a diffence.
Thanks for the help
elliott
Thank you for your input. It was enlightening. Steve, I didn't realize the center of mass of the pistol/hand being below the barrel would cause the muzzle to rise. The compensator is almost six inches long and weighs at least 3 ounces. When I used it, I noticed two effects. One, the sound of the blast seemed to be slightly muted, the "crack" not so loud. Also, the tone of the "crack" was lower on a musical scale. Second, I personally noticed a reduction in the pistol movement on firing. Whether this was due to the effect of the compensator on the gases or just the added weight to the end of the barrel, I do believe there was a diffence.
Thanks for the help
elliott
Ed, Your idea, in a very simular form has been tried, many years ago.
Problems encountered were very significant gas cutting of the orifice, since peak chamber pressure was being vented. If I recall, peak chamber pressure flame temperatures in hi power rifles can exceed 3200F. Rimfire pressures and temperatures are much lower. This is why the recoiless rifle ( artillery ) became obsolete, the gas cuting of the venturies was very problematic. You are right on the money concerning point of impact in handguns. The slower/heavyer bullet will print higher to line of sight, this is a funtion of barrel time. Pistols start to recoil the instant the bullet starts to move, the longer the bullet is in the barrel the more rotation occures about the recoil axis ( wrist ). In fact if you measure a line from top of front sight to top of rear sight, to the bores axis you will find the two lines are out of paralell from 1 to 7 degress, dependind on the caliber and weight of the handgun, the lighter/ larger caliber, the more severe the angle. The barrel is actualy looking below the line of sight to compensate for this effect.
Gort
Problems encountered were very significant gas cutting of the orifice, since peak chamber pressure was being vented. If I recall, peak chamber pressure flame temperatures in hi power rifles can exceed 3200F. Rimfire pressures and temperatures are much lower. This is why the recoiless rifle ( artillery ) became obsolete, the gas cuting of the venturies was very problematic. You are right on the money concerning point of impact in handguns. The slower/heavyer bullet will print higher to line of sight, this is a funtion of barrel time. Pistols start to recoil the instant the bullet starts to move, the longer the bullet is in the barrel the more rotation occures about the recoil axis ( wrist ). In fact if you measure a line from top of front sight to top of rear sight, to the bores axis you will find the two lines are out of paralell from 1 to 7 degress, dependind on the caliber and weight of the handgun, the lighter/ larger caliber, the more severe the angle. The barrel is actualy looking below the line of sight to compensate for this effect.
Gort