1911Tuner
Moderator Emeritus
In light of the recent dustup on the recoil operated/blowback thread that was closed due to becoming derailed, I'd like to open a new discussion and hope that it'll stay on track and remain civil this time. There were still points to be made and things to be learned.
It was suggested that a solid plug be welded into the barrel of both designs...and that the blowback slide would move, while the locked breech slide would not.
And that's correct on both counts...and there's a very simple reason for it.
Before I go further, let's revisit Newton's 1st Law that dealing with an object at rest and how an outside force must be applied in order to make it move.
The law doesn't really provide enough information. Not only must a force be imposed, but that force must also be great enough to overcome the object's resistance to acceleration, whether frictional, inertial, or mechanically imposed, or...in some instances...all three.
If the compelling force isn't great enough to set the object in motion, the object will stand still. The forces involved must be unbalanced in order to produce motion. That is...the compelling force must be greater than the resistive force.
Welding a plug in the barrel of the locked breech pistol creates a system of balanced forces. Welding a plug into the barrel of a blowback...or unlocked breech pistol...doesn't.
Rather than drawing this out, I'll offer a few examples of a balanced force system and see if anyone can determine why the locked breech slide won't move with a plugged barrel...and why the blowback slide will.
Standing in a bucket, you can't pull upward on the handle and lift yourself off the ground. The forces are balanced.
Lock your hands in front of your chest and pull in opposite directions, and neither arm will move. The higher the compelling force, the higher the resistive force. The forces remain balanced.
Place your palms together in front of your chest and push as hard as you can...and neither arm will move...because the forces remain balanced.
Place a 100 pound weight on the floor and impose 100 pounds of lifting force and the weight won't move. (Use 101 pounds of lifting fore...and it will, because the forces have become unbalanced.)
The simple act of standing on the floor is an example of a balanced force vector.
Another term for all these examples is "A state of equilibrium."
Can anyone apply this to the two plugged barrels and see why one will move, while the other will not?
Remember:
In order for movement to occur, the forces must become unbalanced. Balanced forces don't produce movement. The result of balanced forces is a state of equilibrium.
And:
In a locked breech system, whatever resists the barrel's movement backward resists the slide's movement backward, because they're mechanically connected...while in the unlocked blowback...they're not. This is the big clue.
Get your thinkin' caps on...and let's keep this one in the road.
It was suggested that a solid plug be welded into the barrel of both designs...and that the blowback slide would move, while the locked breech slide would not.
And that's correct on both counts...and there's a very simple reason for it.
Before I go further, let's revisit Newton's 1st Law that dealing with an object at rest and how an outside force must be applied in order to make it move.
The law doesn't really provide enough information. Not only must a force be imposed, but that force must also be great enough to overcome the object's resistance to acceleration, whether frictional, inertial, or mechanically imposed, or...in some instances...all three.
If the compelling force isn't great enough to set the object in motion, the object will stand still. The forces involved must be unbalanced in order to produce motion. That is...the compelling force must be greater than the resistive force.
Welding a plug in the barrel of the locked breech pistol creates a system of balanced forces. Welding a plug into the barrel of a blowback...or unlocked breech pistol...doesn't.
Rather than drawing this out, I'll offer a few examples of a balanced force system and see if anyone can determine why the locked breech slide won't move with a plugged barrel...and why the blowback slide will.
Standing in a bucket, you can't pull upward on the handle and lift yourself off the ground. The forces are balanced.
Lock your hands in front of your chest and pull in opposite directions, and neither arm will move. The higher the compelling force, the higher the resistive force. The forces remain balanced.
Place your palms together in front of your chest and push as hard as you can...and neither arm will move...because the forces remain balanced.
Place a 100 pound weight on the floor and impose 100 pounds of lifting force and the weight won't move. (Use 101 pounds of lifting fore...and it will, because the forces have become unbalanced.)
The simple act of standing on the floor is an example of a balanced force vector.
Another term for all these examples is "A state of equilibrium."
Can anyone apply this to the two plugged barrels and see why one will move, while the other will not?
Remember:
In order for movement to occur, the forces must become unbalanced. Balanced forces don't produce movement. The result of balanced forces is a state of equilibrium.
And:
In a locked breech system, whatever resists the barrel's movement backward resists the slide's movement backward, because they're mechanically connected...while in the unlocked blowback...they're not. This is the big clue.
Get your thinkin' caps on...and let's keep this one in the road.