Ideal rate of twist (MLP firearms and shooting thread)

Bigfoot410

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Laser is a 40w. CO2. To engrave or cut metal would really need either a fiber laser or something more powerful. So, no real engraving on metal, more like etching. I've seen a few Glock slides that were done with a similar power:
View attachment 502762
You are correct. I have a 75 watt CO2 laser and can't do bare metal, but you can easily do coated metal and burn through the coating.

You have to have a fiber laser to burn or cut bare metal.

You can burn the coated stainless Yeti cups and stuff like that too. They turn out really nice.

There's also some paint stuff you can spray on bare metal and actually melt it onto the metal and then the non burned area just washes away. Very durable way to print graphics on a bare metal surface.

Here's an example of cups we did for the grandkids. :)

127909405_892627581275486_7459035369406332443_n.jpg
 

CB91710

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Laser is a 40w. CO2. To engrave or cut metal would really need either a fiber laser or something more powerful. So, no real engraving on metal, more like etching. I've seen a few Glock slides that were done with a similar power:
View attachment 502762
Ahh... Ya, slides wouldn't be a problem. For now.
I would imagine that most 80% customers would be wanting to have the work include the DOJ-issued SN, which would mean proper depth. It doesn't take much... a trophy shop could do it, and an 80% would still be kosher without an FFL until the machine work starts. For now.
 

Bownse

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Not sure about the market for those services, but if you are doign any "machining" on a lower, that could be flirting with the line of firearms making. I am not at all sure, but that jumped out at me when I read your post.

Someone here will know definitively, I am sure!
I don't think ATF would have a problem with engraving. As with all such things, a certified return-receipt letter to them requesting an official ruling would be wise to have a reply to if it ever comes up.

DO NOT EMAIL as that won't always hold up in court.
 

JonCanfield

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You are correct. I have a 75 watt CO2 laser and can't do bare metal, but you can easily do coated metal and burn through the coating.

You have to have a fiber laser to burn or cut bare metal.

You can burn the coated stainless Yeti cups and stuff like that too. They turn out really nice.

There's also some paint stuff you can spray on bare metal and actually melt it onto the metal and then the non burned area just washes away. Very durable way to print graphics on a bare metal surface.

Here's an example of cups we did for the grandkids. :)

View attachment 502773
Just curious, is this a home business you're using this for? Part of the reason for getting one was to setup something to get Kathy involved with making some money instead of just spending it
 

Bigfoot410

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Just curious, is this a home business you're using this for? Part of the reason for getting one was to setup something to get Kathy involved with making some money instead of just spending it
Yes. I haven't worked it as hard as I could because I keep getting pulled back to home improvement work by my old boss.

There is tons of potential for what the CO2 can do though. I get most work through friends telling friends, but if you advertised on FB Marketplace or Etsy, the potential is enormous.

My wife also makes tons of Christmas and birthday gifts on it....lol.

I know a few people that make wood items for sale on Etsy, but they were cutting with a scroll saw. I can cut their pieces out in bulk in a fraction of the time and send them out and they assemble whatever it is they are making.

I like that as I don't have to deal with people. Just my contacts. They send me a file, I tune it to work and send 'em their stuff a couple days later. :)

If you have any questions, ideas I can help with or techniques to burn stuff, just drop me a line. I'm no expert, but I've had it for 2 years now and have some insight to screw things up. :)
fusion32m2-model.jpg


I have an Epilog Fusion M2 75watt CO2 laser.
 

ehb

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Son called me about an incident (not him) and asked what I thought.

Thought I would share this with you guys that know more than I. I like pondering on stuff.... He’ll let me know if actual is determined. Not posting pictures or specifics...

Scenario:
.380
Composite lower
Several rounds fired w/ all normal reports
Next round there was an unscheduled slide divorce
Separation is about where rails (kinda) and back bulky section of slide transition
Ammo unknown
Barrel from muzzle to chamber end looks undistorted

My thoughts: Break is at the thinnest part of slide, back of ejection port where it meets (so to speak as slide is one major mass) the greatest mass of slide

My redneck logic says it cannot be ignition outside chamber as there would be distortion of ejection port area, would be rather obvious a flash when case/projectile separate, NOT in chamber would be much less pressure as process is not forcing a projectile down a smaller bore, violates gas laws, and slide would not break like that. I also do not see with modern designs, any way primer could have been hit, especially during new round strip stage. Longitudinally examining end to end, I do not see any lateral distortion of slide or lower.

Could it be a squib stack blow? Would the pressure between lodged squib and new projectile generate enough being .380 to not distort barrel? Thought of that BUT moot option because previous reports were all the same... just last round fired different.


I do not reload .380 so I am ignorant of air space in .380 cartridges. That being said, my only logical answer is a severely overcharged case, if that is possible with cartridge air space. Slide propelled backward with such acceleration that at rearward stop, mass at back section of slide did not wish to stop so snapped slide about at point where the major interior mill-out ended and rear high mass began. Momentum of high mass..One a them Fig Newton laws figures in, methinks...

What do you guys think? (Or ignore...your call... Opportunity to exercise my logic wrench is fun to me)

edro.
 

Roberteaux

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Son called me about an incident (not him) and asked what I thought.

Thought I would share this with you guys that know more than I. I like pondering on stuff.... He’ll let me know if actual is determined. Not posting pictures or specifics...

Scenario:
.380
Composite lower
Several rounds fired w/ all normal reports
Next round there was an unscheduled slide divorce
Separation is about where rails (kinda) and back bulky section of slide transition
Ammo unknown
Barrel from muzzle to chamber end looks undistorted

My thoughts: Break is at the thinnest part of slide, back of ejection port where it meets (so to speak as slide is one major mass) the greatest mass of slide

My redneck logic says it cannot be ignition outside chamber as there would be distortion of ejection port area, would be rather obvious a flash when case/projectile separate, NOT in chamber would be much less pressure as process is not forcing a projectile down a smaller bore, violates gas laws, and slide would not break like that. I also do not see with modern designs, any way primer could have been hit, especially during new round strip stage. Longitudinally examining end to end, I do not see any lateral distortion of slide or lower.

Could it be a squib stack blow? Would the pressure between lodged squib and new projectile generate enough being .380 to not distort barrel? Thought of that BUT moot option because previous reports were all the same... just last round fired different.


I do not reload .380 so I am ignorant of air space in .380 cartridges. That being said, my only logical answer is a severely overcharged case, if that is possible with cartridge air space. Slide propelled backward with such acceleration that at rearward stop, mass at back section of slide did not wish to stop so snapped slide about at point where the major interior mill-out ended and rear high mass began. Momentum of high mass..One a them Fig Newton laws figures in, methinks...

What do you guys think? (Or ignore...your call... Opportunity to exercise my logic wrench is fun to me)

edro.
What make and model was the firearm?

I knew this guy who had some species of Kel-Tec .380. He went to the range with me one day as my guest, and I had the curious experience of observing as the firearm essentially broke into pieces after firing only three rounds. :shock:

Turned out to be some sort of factory defect, and Kel-Tec sent him a new pistol.

That next pistol actually survived a day at the range.

--R
 
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ehb

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What make and model was the firearm?

I knew this guy who had some species of Kel-Tec .380. He went to the range with me one day as my guest, and I had the curious experience of observing as a firearm essentially broke into pieces after firing only three rounds. :shock:

Turned out to be some sort of factory defect, and Kel-Tec sent him a new pistol.

That next pistol actually survived a day at the range.

--R
I’ll post this as it was on a news site...

21FC0C22-428F-4F21-B215-47163B8E7E5A.jpeg
 

ehb

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Wish it was all laying on a flat plane instead of held...
 

ehb

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The gentleman was injured so I would rather not be overly specific as this may well be a drawn out issue.
 

ehb

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Interested to see what Robob can savvy from the pic... He’ll probably catch something I overlooked...
 

JonCanfield

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Yes. I haven't worked it as hard as I could because I keep getting pulled back to home improvement work by my old boss.

There is tons of potential for what the CO2 can do though. I get most work through friends telling friends, but if you advertised on FB Marketplace or Etsy, the potential is enormous.

My wife also makes tons of Christmas and birthday gifts on it....lol.

I know a few people that make wood items for sale on Etsy, but they were cutting with a scroll saw. I can cut their pieces out in bulk in a fraction of the time and send them out and they assemble whatever it is they are making.

I like that as I don't have to deal with people. Just my contacts. They send me a file, I tune it to work and send 'em their stuff a couple days later. :)

If you have any questions, ideas I can help with or techniques to burn stuff, just drop me a line. I'm no expert, but I've had it for 2 years now and have some insight to screw things up. :) View attachment 502919

I have an Epilog Fusion M2 75watt CO2 laser.
Thanks! We went with a Glowforge to start. It had to be something easy enough for Kathy to get into trying. If things go well, we'll add something like this that can do the rotary. Glowforge can only go up to 2.5 inches deep. I can engrave my pens and pen boxes, but not something like a Yeti.
 

Bigfoot410

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Thanks! We went with a Glowforge to start. It had to be something easy enough for Kathy to get into trying. If things go well, we'll add something like this that can do the rotary. Glowforge can only go up to 2.5 inches deep. I can engrave my pens and pen boxes, but not something like a Yeti.
Saw a couple commercials for those. They look like the future of lasers. Ours can be a little complicated with all the tweaking and crap. The Glowforge seems to have simplified a lot of that. Nice machine. :)

If you decide to bigger, get the fiber laser and you can do the neck plates for DSG and gun slides on here...lol.

You can also get contracts for marking medical equipment, tools and tons of other metal products that need serial numbers and stuff.

A fiber laser was a 20K option for our CO2 machine, but we were pretty deep into what we have already. I wish I did get it though.

Best of luck with your venture and you're only limited to your imagination on what you can make. :)
 

CB91710

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Wish it was all laying on a flat plane instead of held...
My first suspicion would be an overcharge, but as you, I'm not familiar with the airspace in the 380.
Could be a long history of +P or +P+ rounds leading to metal fatigue?
Could be a defective slide with an undetected stress riser.
 
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JonCanfield

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Saw a couple commercials for those. They look like the future of lasers. Ours can be a little complicated with all the tweaking and crap. The Glowforge seems to have simplified a lot of that. Nice machine. :)

If you decide to bigger, get the fiber laser and you can do the neck plates for DSG and gun slides on here...lol.

You can also get contracts for marking medical equipment, tools and tons of other metal products that need serial numbers and stuff.

A fiber laser was a 20K option for our CO2 machine, but we were pretty deep into what we have already. I wish I did get it though.

Best of luck with your venture and you're only limited to your imagination on what you can make. :)
Thanks - looking forward to it. I don't have any illusions of being an immediate money maker, but it's worth a shot. If successful, I'd certainly consider doing fiber for a upgraded unit
 

ehb

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My first suspicion would be an overcharge, but as you, I'm not familiar with the airspace in the 380.
Could be a long history of +P or +P+ rounds leading to metal fatigue?
Could be a defective slide with an undetected stress riser.
I think it was new or relatively new.
 

Roberteaux

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Interested to see what Robob can savvy from the pic... He’ll probably catch something I overlooked...
Doubtful! :laugh2:

I don't load for .380 either, but I do have a few reloading manual sitting around here and so I just had a look at the volumetric capacity of the cartridge case itself.

I also kind of skimmed through the load data also, just to get a general idea of what types of powder are commonly used with given projectile weights. There were no surprises when it came to the specific powders listed within my manuals, though the charge weights were news to me.

***************​

Anyway, what I learned was this:

The cartridge case features about 1.1 cc's of "usable capacity" on the average.

"Usable capacity" is generally thought of as being the space inside the cartridge case one has at hand after a bullet has been seated inside the to correct depth for its type and weight.

There will be very minor differences in "usable capacity" from one manufacturer to the next-- but those differences have to do with case wall thickness, and not cartridge case length. Like almost every other cartridge that features "ACP" as part of its name, the .380 ACP headpaces on the mouth of the case... and so the case lengths tend to be extremely consistent compared to the variances one might note in case wall thickness, which are themselves generally minuscule.

So, when it comes to overcharging a .380 ACP cartridge, it sure looks like it would be easy to do for somebody who is sloppy, careless, and unobservant enough.

Again: the cartridge case gives you 1.1 cc's of space for powder.

I found that bulkier flake powders (such as Unique) will displace only about .44 of those 1.1 cc's... leaving a full .66 cc's of "usable capacity" empty.

If you're using a more compact spherical powder (such as HP-38 or Winchester 231), your charge will only displace .30 cc's... leaving .80 of those 1.1 cc's with space left for mo' powder. Thus, it's physically possible to actually triple-charge a .380 case.

I was unable to find any data at all regarding powder "detonation" as the result of an undercharge of powder in .380 ACP, and so I take it that detonation isn't an issue with the cartridge type, as it is with various others.

It doesn't look like a squib. The barrel doesn't show the sort of damage common to a live round fired into a projectile stuck in the barrel... but then, .380 ACP isn't exactly a real monster in the chamber pressure department. There appear to be a very few loads that approach 20K PSI... but most of 'em seem to be pushing more like 12K - 14K.


But yeah, I agree that the damage in the photo looks like it could have been the result of an over-charged cartridge. And if it's not that, then perhaps the slide was somehow defective? But that's about all I could guess at.

Gunmonkey could probably sort it out better for us.

I do know this much, however: that particular manufacturer has always seemed to have difficulties with the models they've produced in .380 ACP. Over the years, there have been recalls, models that bombed after word got out that they were jam-a-matic junkers, and blah-blah-blah.

That happened most recently with the Spectrum model. If I was running that company, I'd have my smurfs sticking to building their .38 Super models. Some of those are actually very nice.

--R
 

ehb

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Doubtful! :laugh2:

I don't load for .380 either, but I do have a few reloading manual sitting around here and so I just had a look at the volumetric capacity of the cartridge case itself.

I also kind of skimmed through the load data also, just to get a general idea of what types of powder are commonly used with given projectile weights. There were no surprises when it came to the specific powders listed within my manuals, though the charge weights were news to me.

***************​

Anyway, what I learned was this:

The cartridge case features about 1.1 cc's of "usable capacity" on the average.

"Usable capacity" is generally thought of as being the space inside the cartridge case one has at hand after a bullet has been seated inside the to correct depth for its type and weight.

There will be very minor differences in "usable capacity" from one manufacturer to the next-- but those differences have to do with case wall thickness, and not cartridge case length. Like almost every other cartridge that features "ACP" as part of its name, the .380 ACP headpaces on the mouth of the case... and so the case lengths tend to be extremely consistent compared to the variances one might note in case wall thickness, which are themselves generally minuscule.

So, when it comes to overcharging a .380 ACP cartridge, it sure looks like it would be easy to do for somebody who is sloppy, careless, and unobservant enough.

Again: the cartridge case gives you 1.1 cc's of space for powder.

I found that bulkier flake powders (such as Unique) will displace only about .44 of those 1.1 cc's... leaving a full .66 cc's of "usable capacity" empty.

If you're using a more compact spherical powder (such as HP-38 or Winchester 231), your charge will only displace .30 cc's... leaving .80 of those 1.1 cc's with space left for mo' powder. Thus, it's physically possible to actually triple-charge a .380 case.

I was unable to find any data at all regarding powder "detonation" as the result of an undercharge of powder in .380 ACP, and so I take it that detonation isn't an issue with the cartridge type, as it is with various others.

It doesn't look like a squib. The barrel doesn't show the sort of damage common to a live round fired into a projectile stuck in the barrel... but then, .380 ACP isn't exactly a real monster in the chamber pressure department. There appear to be a very few loads that approach 20K PSI... but most of 'em seem to be pushing more like 12K - 14K.


But yeah, I agree that the damage in the photo looks like it could have been the result of an over-charged cartridge. And if it's not that, then perhaps the slide was somehow defective? But that's about all I could guess at.

Gunmonkey could probably sort it out better for us.

I do know this much, however: that particular manufacturer has always seemed to have difficulties with the models they've produced in .380 ACP. Over the years, there have been recalls, models that bombed after word got out that they were jam-a-matic junkers, and blah-blah-blah.

That happened most recently with the Spectrum model. If I was running that company, I'd have my smurfs sticking to building their .38 Super models. Some of those are actually very nice.

--R
Thanks... Could be defective but both sides letting go but I would think it would be one side and if it took the other from a crack/fault there should be evidence of a torque before other side gave up.... I don’t see that... I’ll go with overcharged...

I’ll share if sone finds out the actual determination....

Thanks Robob and others.. I enjoy trying to figure out stuff... I’ve actually been correct a time or two... ok, I was close.... ;)
 


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