.460 Rowland--Yeah, it's for real....

[The_Shadow]

BTW the video of the G-19 doesn't eject the spent casing...No Ejector! or Broken Ejector!

Yes the Barrel and slide do start to move as a result of the cartridge being fired and before the bullet leaves the bore.
It is also why I like the fact that a non captive recoil spring exerts slightly more pressure to hold the slide closed.
Some captive factory springs have been known to just fall out while removing the slide from the frame, I have to believe this may in fact be a cause for early unlock.  I could be wrong but, I have more confidence with the non captive set up from Wolff with a measured difference being applied to hold it in battery.

[DM1906]

With all respect to a long forum member, nothing you are describing aligns with the basic laws of physics I learned in college, and have applied to accurately predict slide travel in recoil operated handguns.

An 'over comped' gun will fail to function because a significant percentage of the recoil mass is now part of the barrel/comp, which robs the slide of needed momentum, in addition to slowing it's velocity.

I don't know what the term comparative mass means.  Google didn't help.  It sounds like an oblique reference to Newtons 3rd law, which also implies conservation of momentum.

However, even in modern designs (Glock?) which use a "locking block ramp" (google only knows locking block) or a "ramped lug" (lots of results related to AR-15's) if the slide/barrel is free to move, it will move some before the bullet leaves the barrel.

Glock 19 at 1200 frames/sec. https://www.youtube.com/watch?v=7Fr5ccyriJI

You have to watch closely, but the barrel/slide do move pre-bullet exit.

I am not trying to pick a fight.  I am trying to make sure we have accurate information on the forum.

Comparative mass (in this case): Mass of the projectile vs. the mass of the firearm. "Projectile" represents the components that are not physically attached to the firearm, including the bullet, combustibles and resultant properties (gas).

The video does demonstrate it very well. (Visible) gas is present at the muzzle before slide rearward movement. The video was intended to demonstrate other characteristics, but it can be seen, but not at (the stated) 1200 FPS. I slowed it to about 12,000 FPS. Only the set at 1:30 actually shows the trigger pull. Unfortunately, we can't see the striker fall, as you can the hammer fall on a 1911. Similar videos of a 1911 firing show the same. No slide movement and no barrel unlock until gas exits the muzzle. The physical laws DO support it. (unloaded pistol) Grasp the slide and push/pull on the barrel. It remains locked. Only the slide and barrel moving rearward, in relation to the frame, caused them to unlock. The same condition applies during ignition. Something causes them to move rearward. At the time of ignition, the barrel and slide are locked together, with the cartridge case and bullet contained within. As the expanding gas forces the departure of the bullet and case, the pressure is applied equally, to the bullet and breach. Something must, independently, force the entire assembly rearward. That is the gas. As with all things in nature (except my wife), it will take the path of least resistance. The mass of the slide is much greater than that of the bullet (about 50:1, as it is in the video). The bullet moves in relation to nature, as does the barrel/slide. Add to the equation, the bullet-bore friction, as well as the compression of (atmospheric) gas forward of the bullet added to the escaping explosive gas around the bullet. The end result is, it is all about the gas. The additional mass of a compensator and/or longer barrel is of little consequence. If it were, we wouldn't need to port it to gain the desired affect. The same bullet at the same velocity with a more or less "gassier" powder charge can vary from violent slide velocities to nearly no action cycling. I can demonstrate this at will.

Blow-back action (often improperly referred to "recoil action"), the expanding gas causes the force between the bullet and case. They both move away from each other at exactly the same rate of energy. The comparative mass insists the bullet move away at a much higher velocity.

With gas delayed action, it's no different, except the action is held mechanically locked, by gas pressure, until the pressure drops to a specific level. In almost every case, this is after the projectile bullet (the resistance) exits the muzzle. "Gas operated semi-automatic" rifles are essentially the opposite. The action remains mechanically locked until the pressure behind the bullet (the resistance) accesses the gas port, releasing the mechanical lock, by any number of means.

In every example, it's the gas that initiates and operates the action. Recoil is what you feel after all that goings-on is done.

[DM1906]

BTW the video of the G-19 doesn't eject the spent casing...No Ejector! or Broken Ejector!

I noticed that, too. More likely a misaligned ejector. The case does ride the slide all the way rearward. In the later demonstrations, with a magazine in place, we see the case being pushed up/outward.

Yes the Barrel and slide do start to move as a result of the cartridge being fired and before the bullet leaves the bore.
It is also why I like the fact that a non captive recoil spring exerts slightly more pressure to hold the slide closed.
Some captive factory springs have been known to just fall out while removing the slide from the frame, I have to believe this may in fact be a cause for early unlock.  I could be wrong but, I have more confidence with the non captive set up from Wolff with a measured difference being applied to hold it in battery.

We aren't seeing the same thing, then. It isn't possible, by design. The projectile includes the bullet, the combustible, and all the resultant properties. It is possible for significant gas to exit ahead of the bullet (as seen in that video). This, coupled with atmospheric pressure resistance can cause movement, but in all but the rarest of cases is it enough to force the action. I suspect the very generous Glock freebore, an undersize bullet (or oversize bore), and/or just a worn out pistol.

In regards to the springs....
The non-captive springs don't exert any more static pressure than captive, unless they are heavier to begin with. The correct sized RSA, be it OEM or aftermarket, doesn't float freely when installed. It should be engaged forward at the slide hole, rearward at the frame just ahead of the slide lock, and should be tensioned at all times. With your Glock disassembled, install the OEM spring into the slide hole, noting the protrusion of the tip. Now, install the slide to the frame. It should protrude slightly more, indicating a proper fit and tension. They sometimes fall out at disassembly because they miss the "holding" pad on the barrel as it's disassembled. It happens to all of my Glock pistols at one time or another. I had considered using non-captured springs at one time, but opted for steel rod captured. They've served me well for a couple decades. If the spring isn't properly tensioned, it is either the wrong spring, or something is worn/broken, such as the slide lock. There's nothing wrong with the non-captured springs, IMO. I just prefer what I'm using. I've shattered a couple OEM guide rods, but haven't had any issues with steel.

[my_old_glock]

...
I understand perfectly how it works. As I said, recoil is a product of gas expansion. Recoil is nothing more than what the shooter "feels". The expanding gas initiates comparative mass departure. Kinetic and potential energies complete the cycle. Newton's laws describe it. Delayed blow-back, by any definition, is the manipulation of gas timing, regardless of the implementation.

Recoil is the product of the conservation of momentum.



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[DM1906]

...
I understand perfectly how it works. As I said, recoil is a product of gas expansion. Recoil is nothing more than what the shooter "feels". The expanding gas initiates comparative mass departure. Kinetic and potential energies complete the cycle. Newton's laws describe it. Delayed blow-back, by any definition, is the manipulation of gas timing, regardless of the implementation.

Recoil is the product of the conservation of momentum.



.

Sure. By that loose application of Newton's Law, every firearm created since the flintlock is recoil operated. Recoil is a product of the event of gas expansion, in this discussion. I never said recoil IS gas expansion.

[EdMc]

Uh...not to interrupt, but my question was about certain powders supposedly generating more gas. Or is this just another way of saying a slower burn leads to more gas? Or some elements of the compound cause more gas?

[my_old_glock]

Uh...not to interrupt, but my question was about certain powders supposedly generating more gas. Or is this just another way of saying a slower burn leads to more gas? Or some elements of the compound cause more gas?

Generally the heavier the powder charge the more gas is generated. The long chain molecules that make up the solid powder are broken apart, and then reform into gas molecules (N2, O2, CO2, H2O, H2, etc). Two different powders of the same weight, but different burn rate should produce the same amount of gas molecules. The slower burning powder just produces them gas molecules at a slower rate.



.

[my_old_glock]

...
I understand perfectly how it works. As I said, recoil is a product of gas expansion. Recoil is nothing more than what the shooter "feels". The expanding gas initiates comparative mass departure. Kinetic and potential energies complete the cycle. Newton's laws describe it. Delayed blow-back, by any definition, is the manipulation of gas timing, regardless of the implementation.

Recoil is the product of the conservation of momentum.



.

Sure. By that loose application of Newton's Law, every firearm created since the flintlock is recoil operated. Recoil is a product of the event of gas expansion, in this discussion. I never said recoil IS gas expansion.

I never said you did say that.


https://en.wikipedia.org/wiki/Recoil_operation

https://en.wikipedia.org/wiki/Gas-operated_reloading


I know when a friend of mine is drunk because he becomes an expert on everything. When he is drunk, he knows more about the ocean than Jacques Cousteau; he knows more about rockets than Wernher Von Braun; he knows more about the surface of the moon than Neil Armstrong; he knows more about he Universe than Carl Sagan.


.

[DM1906]

...
I understand perfectly how it works. As I said, recoil is a product of gas expansion. Recoil is nothing more than what the shooter "feels". The expanding gas initiates comparative mass departure. Kinetic and potential energies complete the cycle. Newton's laws describe it. Delayed blow-back, by any definition, is the manipulation of gas timing, regardless of the implementation.

Recoil is the product of the conservation of momentum.



.

Sure. By that loose application of Newton's Law, every firearm created since the flintlock is recoil operated. Recoil is a product of the event of gas expansion, in this discussion. I never said recoil IS gas expansion.

I never said you did say that.


https://en.wikipedia.org/wiki/Recoil_operation

https://en.wikipedia.org/wiki/Gas-operated_reloading


I know when a friend of mine is drunk because he becomes an expert on everything. When he is drunk, he knows more about the ocean than Jacques Cousteau; he knows more about rockets than Wernher Von Braun; he knows more about the surface of the moon than Neil Armstrong; he knows more about he Universe than Carl Sagan.


.

I don't know how to be more clear, and I'm not a think as you drunk I am. Categorical classifications aren't in dispute, and Widipedia is about as reliable as scribbling on a restroom wall. We know what they are called, regardless of how they actually work, which is my point. Short of a genuine "machine" gun, all self-loaders are reloaded by recoil, in the strict definition. Recoil doesn't provide any energy, nor does it initiate any process. Recoil is a simple name for one result of a complicated process of conversion and storage of energy. As I said before, it doesn't matter to me what it's called, it's all about the gas, and what we do with it. Recoil, within the firearm, is only a very small piece of a very large puzzle. I'm not redefining a classification. I'm describing a process. When the world was flat, it wasn't. It was flat because that is what they saw, and that is what they called it. Some people today still believe that.

[Captain O]

I have wondered how viable the .460 Rowland is as a hunting and/or combat cartridge. Does it work at the same ranges as our beloved 10mm? What type of trajectory does it offer? Is it similar, or does it arc as do the other big bore Magnum cartridges?

I am ashamed to say that I have yet to research the cartridge adequately to gain a complete understanding.

Captain O

[DM1906]

I have wondered how viable the .460 Rowland is as a hunting and/or combat cartridge. Does it work at the same ranges as our beloved 10mm? What type of trajectory does it offer? Is it similar, or does it arc as do the other big bore Magnum cartridges?

I am ashamed to say that I have yet to research the cartridge adequately to gain a complete understanding.

Captain O

It's viable as a hunting platform, not so much as a combat piece, IMO. Perhaps for a specialized need, but not practical. There are many SBR options much better suited to those tasks.

Same range as the 10mm? I'd say so. It has as much bullet energy at 100 yds, as the 10mm at the muzzle (with a VERY healthy round). No mysteries with the trajectory. It follows the same rules. It's the bullet mass and B.C. vs. the atmosphere. To be more specific, with a 50 yd. zero, the holdover at 100 yds. is 4.7" with a trajectory apogee of 0.5" @ 26 yds (calculated, then confirmed). This with the 230 gr. XTP, 1366 FPS (953 ft/lb) @ 50 yds, and 1238(783) @ 100 yds. This according to the latest testing session, with still some room for increase. Next up for testing is the Hornady 225 gr. FTX. This should be interesting!

[BEEMER!]

I have just bought a Clark Conversion and had it fitted to a Colt Govenment model.

I have Power Pistol, #7, and Longshot powders.  I will probably start loading 230 grain FMJ's as I have a lot of them.  Clark recommended starting with the 20# spring and move up to the 24# as my loads go up.

Where would you recommend starting?

[DM1906]

I have just bought a Clark Conversion and had it fitted to a Colt Govenment model.

I have Power Pistol, #7, and Longshot powders.  I will probably start loading 230 grain FMJ's as I have a lot of them.  Clark recommended starting with the 20# spring and move up to the 24# as my loads go up.

Where would you recommend starting?

First, I STRONGLY recommend slugging your bore and measuring the bullet diameters. While Longshot didn't seem to matter much, AA7 was quite sensitive to the overbore differential. Also, seat them as long as you can reliably feed them. I can reliably seat 230 gr. XTP's at 1.289", in my pistol. Start long, and reduce as necessary, but be sure to adjust and work up the powder charge accordingly. The big bullets eat up case capacity very quickly. Also note, my barrel is 6.6" with a tuned comp. YMMV.

Starting load recommendations:
AA7, 14.0 gr. start, 15.8 gr. MAX @ 1.275" COL.
LS, 10.6 gr. start, 12.0 gr. MAX @ 1.275" COL. (velocity began to plateau 11.6-11.8 gr., for me)

PP is too fast, IMO. Perhaps OK for plinkers (.45Super limit), but I would not recommend pushing it up. There are some PP loads published around the net, but it's far from practical, IMO. It may not get along with your comp, either. Autocomp and HS7 have some potential, though.

Blue Dot is also an excellent powder for the .460R, but I DO NOT recommend trying it unless you are experienced and comfortable with powder charge compression, which will be required for optimal performance. Forget trying any slower powders. They just don't fit!

[Captain O]

I have wondered how viable the .460 Rowland is as a hunting and/or combat cartridge. Does it work at the same ranges as our beloved 10mm? What type of trajectory does it offer? Is it similar, or does it arc as do the other big bore Magnum cartridges?

I am ashamed to say that I have yet to research the cartridge adequately to gain a complete understanding.

Captain O

It's viable as a hunting platform, not so much as a combat piece, IMO. Perhaps for a specialized need, but not practical. There are many SBR options much better suited to those tasks.

Same range as the 10mm? I'd say so. It has as much bullet energy at 100 yds, as the 10mm at the muzzle (with a VERY healthy round). No mysteries with the trajectory. It follows the same rules. It's the bullet mass and B.C. vs. the atmosphere. To be more specific, with a 50 yd. zero, the holdover at 100 yds. is 4.7" with a trajectory apogee of 0.5" @ 26 yds (calculated, then confirmed). This with the 230 gr. XTP, 1366 FPS (953 ft/lb) @ 50 yds, and 1238(783) @ 100 yds. This according to the latest testing session, with still some room for increase. Next up for testing is the Hornady 225 gr. FTX. This should be interesting!

Interesting cartridge to say the least! This puts it right up with someof the other Magnum handgun rounds. It looks as if it is an easy transformation and it isn't irreversible. Segregating the sets of conversion parts, however, are an absolute requirement!

[BEEMER!]

I have just bought a Clark Conversion and had it fitted to a Colt Govenment model.

I have Power Pistol, #7, and Longshot powders.  I will probably start loading 230 grain FMJ's as I have a lot of them.  Clark recommended starting with the 20# spring and move up to the 24# as my loads go up.

Where would you recommend starting?

First, I STRONGLY recommend slugging your bore and measuring the bullet diameters. While Longshot didn't seem to matter much, AA7 was quite sensitive to the overbore differential. Also, seat them as long as you can reliably feed them. I can reliably seat 230 gr. XTP's at 1.289", in my pistol. Start long, and reduce as necessary, but be sure to adjust and work up the powder charge accordingly. The big bullets eat up case capacity very quickly. Also note, my barrel is 6.6" with a tuned comp. YMMV.

Starting load recommendations:
AA7, 14.0 gr. start, 15.8 gr. MAX @ 1.275" COL.
LS, 10.6 gr. start, 12.0 gr. MAX @ 1.275" COL. (velocity began to plateau 11.6-11.8 gr., for me)

PP is too fast, IMO. Perhaps OK for plinkers (.45Super limit), but I would not recommend pushing it up. There are some PP loads published around the net, but it's far from practical, IMO. It may not get along with your comp, either. Autocomp and HS7 have some potential, though.

Blue Dot is also an excellent powder for the .460R, but I DO NOT recommend trying it unless you are experienced and comfortable with powder charge compression, which will be required for optimal performance. Forget trying any slower powders. They just don't fit!

Thanks for the advice. 

I thought that Power Pistol seemed a little fast, but the data I have seen listed it and it was on my shelf anyway.

I really like Blue Dot and I used to load it compressed in 357 Sig if I remember right.  Can you direct me to a source of information regarding compressed loads with it?