Lane's: jtallen83 inspired 21.750" 300 AAC Blackouts

[Lane]

1 minute ago, 98Z5V said:

There's something happening in the last few days, and I think I was the first issue with it. 

I see "*PAPERCLIP* Loading..." in the area where I should be able to drag images. It just doesn't work at the moment... I suppose I could host them elsewhere and inline the content? Can't post a screen shot; because, it's broken...

[98Z5V]

53 minutes ago, Lane said:

I see "*PAPERCLIP* Loading..." in the area where I should be able to drag images. It just doesn't work at the moment... I suppose I could host them elsewhere and inline the content? Can't post a screen shot; because, it's broken...

Next few days will get it resolved, major progress tonight, that's for sure.

I think I'm the one that either exposed, or threw the monkey wrench into - the glitch in the Matrix. Probably the latter.  I could break an anvil in a sand pit.

[Lane]

How do you wish to break your anvil in the sandpit? You are birthing a new anvil?? What is a made of? Does it have a special top surface?

[Lane]

Forcing an anvil is hard if you want to do it right. Maintaining an anvil is only easier if you have plenty of anvils (plural)...

[98Z5V]

4 minutes ago, Lane said:

How do you wish to break your anvil in the sandpit?

Bare hands.

[Lane]

A

28 minutes ago, 98Z5V said:

Bare hands.

Not at all sure if one could break any kind of anvil with bare hands; especially considering the tools at hand, or varied construction. Fabrication of the anvil could be well evaluated with it's age? A fist or sledge hammer might break only the weakest of anvils on the shelf...

[Robocop1051]

13 hours ago, Lane said:

A

Not at all sure if one could break any kind of anvil with bare hands; especially considering the tools at hand, or varied construction. Fabrication of the anvil could be well evaluated with it's age? A fist or sledge hammer might break only the weakest of anvils on the shelf...

You give an “unbreakable” object to soldier or a cop, and we are going to make a liar out of the manufacturer before we return it. 

I know a grunt who was locked in an empty room, buck naked, with only two large, steel, ball-bearings. When they recovered him 12 hours later they discovered that he broke one and lost the other. 

“This is not mission difficult, Mr. Hunt, it's mission impossible. Difficult should be a walk in the park for you.” -Mission Commander Swanbeck

[jtallen83]

There's a reason this company calls itself RangerProof, and I doubt they think their stuff can't be broke but they do know the height of the bar they set. 

https://rangerproofswag.com/

"Rangers are inherently hard on gear, and equipment by virtue of their jobs. We knew that if a Ranger could not break it or make it inoperable, he would just eat it. Our gear is made tough enough for a Ranger…. and totally inedible. Our shooting gear products are RANGER PROOF."

Edited August 8, 2019 by jtallen83

[Lane]

34 minutes ago, Robocop1051 said:

You give an “unbreakable” object to soldier or a cop, and we are going to make a liar out of the manufacturer before we return it. 

I know a grunt who was locked in an empty room, buck naked, with only two large, steel, ball-bearings. When they recovered him 12 hours later they discovered that he broke one and lost the other. 

“This is not mission difficult, Mr. Hunt, it's mission impossible. Difficult should be a walk in the park for you.” -Mission Commander Swanbeck

This made me laugh.

Breaking a real anvil isn't impossible. Though; a well made anvil has a welded steel face. One could break off the horn, shatter a foot, a corner of the heel, etc... I guess that would make on an "edgecrusher".  But break the core of the anvil by hand? So far as I'm aware; that's only possible if there were a serious flaw in manufacturing. Also; if you're good enough, that anvil can still be repaired in a day with the right tools at hand. Forge weld that B.... back together again!

[98Z5V]

You ever been around a platoon of Rangers?

You yell out at morning PT formation, when they're only dressed in t-shirts, Ranger Panties and running shoes, "Hey you motherfuckers!  There's an anvil in the middle of the hand-to-hand pit over there - first one of you dickheads that breaks it gets a 4-day pass..." 

That anvil is done...  

It's gonna be SAVAGE.

Edited August 9, 2019 by 98Z5V

[Lane]

I had a part of a message typed out here (but it disappeared); I've been quietly experimenting with the problems on this site. Not sure I know much yet; but there were some good tips posted about how to work around the no-pictures issue.

Got some new shot timer hardware (though not the flagship model) yesterday. I'm quite happy with the build quality and features. There are a few minor code changes to support these other boards due to on-board peripherals using pins I had assigned to other functions. Simple enough to create a define tree at the top of my source code to allow hardware variations. I already do it for breadboard vs. prototype builds that use different display driver chips. This will add at least two more hardware options to that existing list

These newer dev boards are actually marketed as WiFi Deauth devices; but honestly, I can't come up with even joke-like ways to have fun with that. Piss off some Starbucks customers, or people trying to "work" in a bookstore; who cares? One can also find some listed as "Weather Stations"; another use case for small WiFi connected computers. What that kind of use based development created though; was a whole array of new development boards with built in controls, peripherals, electronic hardware, and cases. Some of them have battery connectors now so I can remove the DC/DC converter, LiPo charger, etc.; almost all the internal wiring in the prototype. On board controls, real time clock, and soon a digital microphone too? I'm still trying to catch up with everything that happened in six months time.

Reviewing all of this has given me some perspective on where I need to go next with this project. There are a few upgrades that will need to trickle backwards into prototype units when I work with the code base again. Another advantage of having this array of hardware is being able to test things round-robin without blowing away previous iterations. Being able to test side-by-side should speed up development on the few last things I had on my list. The yellow board with built in controls has a lot of extra LEDs; it would be ideal for visual cues in conjunction with (or alternative to) the standard audible indicator. I'll withhold the smaller and cheaper flagship design pictures until I can prove code on that model of hardware (might not be soon). 

Called RCBS about the chrono issues and it was agreed, that I need to test the unit at high noon in full sunlight. It's not (apparently) going to work in the shade of a building, under a tent, or after the sun drops behind the mountain in early evening. Why this is not an editable software parameter; or sensitivity adjustable with screw type potentiometers is beyond my comprehension, other than knowing it's straight Chinese hardware design from an American build spec. Built to a price point in every way possible; it just barely works, but the profit margins should be enormous if they didn't spend too much on R&D. Support also mentioned that there are other types of chronos that don't require light to function (thanks for the tip).

Need to get all my images ready to post during the short window of time I'm allowed editing privileges. It's a hack; but it does work for posting files in reply messages. Here's a graph of grain weight in processed new LC18 brass -> 300 Blackout. The flatter parts (smallest slope) are ideal in terms of consistency. I still need to measure water volumes; but my expectation is reasonable continuity. I'll post up the fired brass soon; I want chrono data, and targets to match up with for that to matter to me personally. The rest are shot timer boards, and the mass of wiring I can mostly remove from future builds; those LEDs can be very bright... Hopefully not seizure inducing in operation.

Edited August 10, 2019 by Lane
Images

[shooterrex]

Saw this it might be something you could use.

[Lane]

I saw pictures of the KaliKey a while back, and was turned off by the idea of removing a staked gas key on a BCG. It was actually a part of the motivation to cast my own charging handles for straight pull specific builds (no intention of certifying them for semi-auto use though). Waxes are ready for casting; but I got sidetracked and excited by an induction furnace in the mean time. Now there is a high power unit on the way that will allow me to pour those with even less effort; since they are so small in volume. I was kind of shocked again when I ran the numbers just now. Even with a little gating on the wax it's only (15 grams of wax); a mere 1 cubic inch of metal to pour. I actually have a crucible right here that's plenty large for a few at that volume.

That said; the KaliKey may not pass the muster of NYS law given the arbitrary nature of prosecution here (especially following some high profile gun related incidents). Take for example the Andreychenko case being charged in Springfield, WI; a lawyer is quoted in many of the news articles saying "if he went to Wal-Mart before the El Paso incident happened, it's likely he wouldn't have been charged". Unfortunately the NY State Police refuse to clarify the details of the SAFE Act here; the word is "err on the side of caution, and: if you're not breaking the law, you have nothing to worry about". For reference; the bullet button is not legal here in NY either (and never has been); due to the loose wording/lack of clarification with our laws. 

The legal problem I see with the KaliKey is the removal of the gas key while retaining a gas system. The firearms examiner is allowed to disassemble and reassemble the parts they receive in any way they see fit (a sort of constructive possession approach). This makes sense when you consider a gun that may have jammed in a shootout with police. In that situation; the gun as received may not be capable of firing without disassembling and putting back together. The inspector is allowed to clear the jam, and return the firearm to working order to enable all appropriate charges to move forward in the case. That all makes sense from a legal and judicial perspective. 

In the case of the KaliKey though; if a gas key is recovered (or perhaps found unused in another build), it could be installed and would make a gun with a gas system (and other features) become an assault rifle. My current position is to avoid that type of confusion by not having a gas port drilled in the barrel (since the firearms examiner isn't allowed to do any gunsmithing work). From a legal perspective I could even own or install gas blocks and gas tubes in that case; even drill bits. Were a gun to have a functioning gas system and no gas key; it could also give the appearance of trying to skirt the law, or make a mockery thereof (best avoided). 

Quite frankly, it's sad that we have to think this hard about poorly written gun laws to begin with. California has a nice flowchart explaining what is legal and what is not. The rule of law (and prosecution thereof) is completely arbitrary in the state of New York. Did one meet a police officer who believes all citizens should be disarmed? Did one get noticed on a day following some panic inducing gun related tragedy? Does the DA or other interested party wish to tout how well the strict NYS gun laws are working?

Are there other ways to run afoul with those laws? Yes; absolutely. All I can do is hedge my bets in the most logical way possible, and hope I never need to hire a lawyer to fix things for me. I recently read somewhere; "The New York State motto: Not breaking the law? We'll keep changing it (quietly, in the middle of the night) until you are". Sad way way of life around here... I should probably prepare to burn out a mold so I can pour these new (gas key compatible) handles sooner rather than later. 

[shooterrex]

I thought you built the guns without gas tubes and gas blocks. I thought this would make removing fired cases out of the chamber easier. More to hold on to.

On another forum some people were installing the gas block upside down to block the port and not using a gas tube at all.

[Lane]

2 hours ago, shooterrex said:

I thought you built the guns without gas tubes and gas blocks. I thought this would make removing fired cases out of the chamber easier. More to hold on to.

Not wrong at all here; I was simply trying to explain the absurd nuances of the terribly written NYS laws; as well as the practices beyond. I firmly believe our laws were supposed to be a copy of California; but in the haste to craft and pass them much was lost. I hope no other states try to copy this mess.

So; as a drop in replacement with an existing gas system in place; not sure the KaliKey is totally legal with any evil features installed. Probably fine to take to the range; but not going to be a good situation to be in if one is subject to search or confiscation. 

2 hours ago, shooterrex said:

On another forum some people were installing the gas block upside down to block the port and not using a gas tube at all.

This is also a grey area for the same reason. Probably fine at the range; but if a search of your possessions turns up a gas tube that fits, might have an assault weapon charge with any other feature involved.

Now; one might ask, what are the odd of having a problem at home? Typically I would say very small, but the police stopped by here a few weeks ago at 11:30PM because a neighbor called them. They come up here to see if I knew anything about a car parked down the road (which I didn't). I'm quite sure they were trying to avoid paperwork in the matter, and were quite friendly. On the other hand (hypothetically speaking); what if they stopped by at 11:30AM when I was setting up to shoot these through a chrono? Reasonably sure they wouldn't be able to help themselves with all these evil pistol grips showing. Sure it wasn't the intent of their visit; but you know they have to ask once they see them... I'm sure as hell not about to invite scrutiny just to find out what happens. 

So; all in all, the KaliKey is a nice drop in option for some people; in some places. I think the cost was the biggest turn off when I first saw these; but also the removal of staked gas keys. I spent less than $10 making the charging handle mold for custom modifications. With a dozen waxes I can make any number of modified grips for these hard to remove cases. 

You can see excess gating on the grip and the tip of the handle; those remain to connect to the sprue system. The waxes are deliberately oversize so they can be trimmed down slightly as wax or metal. My preference here would be working in the metal for this project (a little hammer work adds strength). Since my scopes already stick out the back, my early modifications stress a rear extension of the handle grips as well as increased width.

This crucible and my existing 1,000 Watt induction heater should be plenty to pour even modified handles. Excuse the extra white fluff; ceramic insulation makes the heating process much faster and more efficient. 

Edited August 12, 2019 by Lane
image hack

[Lane]

I've had the new shot timer hardware on my desk for a while now. I finally got around to combining/compiling a bunch of library example code to flesh out the necessary framework to port the old shot timer code over. This new hardware is actually cheaper; with a lot of extra features. While the old design had WiFi for configuration and data transfer, along with a single audio input; this new unit adds a host of new features without losing much at all. Shown here with a quarter for scale (it's quite small); it adds Bluetooth (still has WiFi), swaps the monochrome OLED for a built in color LCD display, internal LiPo battery, 6 axis IMU that supports 1000Hz accelerometer, and 32kHz gyroscope, real time clock, build in microphone with digital input, buttons, visible LED and IR, and the included case. The only thing it's missing is the rotary encoder for scrolling options; but that can be added to one of the plugs on either end, and still look relatively seamless.

While it may not be immediately obvious; that's a set of stacked audio waveforms on the screen. I've gotten most of the basics up and running (web server, display routines, audio input). Porting the old shot timer code won't be an overnight job, but I can finally move forward with it as I have free time. It may even be able to replace the accelerometers (using the Gyros instead actually simplifies circuity) I was planning to use for measuring barrel movement. Having the mic (and additional ADCs on board) will allow me to directly correlate some of that data without other external hardware. 

Best part is; these can be had for a mere $10.99. I think it will benefit from a larger battery, second analog microphone (or two?), and it would be nice to have the rotary encoder for ease of use. All that should still come in well below $20 total. 

Here is a peek at 15 of the 16 pieces of brass I've fired through the pair of 300 Blackout builds (no idea how I lost one; going to have to look for that). These were from the sighting in a while back. It was a magazine loaded with two each of four different off the shelf loads, with ascending projectile weights. As I mentioned before; BOTH builds failed to close on the GO gauge, something I considered to be a fine in terms of long term use, as well as accuracy (though the accuracy claim may well be pure conjecture, just an assumption based on prior reading). I had no issues chambering any of these factory loads; and the bolts came very close to closing on the GO gauge. The only thing I noticed was a little bump on the shoulders which doesn't concern me much. I fully suspect the GO gauge will close well before I hit the hundred round mark on each. 

I've actually acquired some more factory load options since then; but want to wait for a functional chronograph setup before I continue any further testing. At this point I might as well wait until I can collect barrel movement data as well (since it may be much easier now). Not sure exactly when I'll get back to testing this, but I've got some interested parties locally that would like to participate; and hunting season is fast approaching. Still working to craft a complete methodology for this future testing, but have made significant progress already. I'll post that back here when I near a final product. 

[Lane]

It turned out to be less than an overnight project to port over the bulk of the shot timer code base. First I needed to disable all the graphics routines; but the web interface has been working for almost a week now. It even uses the (new) built in digital microphone for the shot pickup. One of the last major hurdles is finishing the cold install of the file system.

That is something that's been on my bug list for a long time... Making sure brand new hardware; upon uploading the firmware, creates and populates all the data files (or even second boot for that matter). Up until more recently I was working with 1-2 prototypes, so that didn't have to happen automatically. I always had to perform a list of tasks; scrolling certain menus, logging into the web interface, submitting forms, faking shots, pressing buttons in order; all that needs to be fixed. It's a pretty simple test though: "does new hardware detect empty or partial file system, and fix every error"? Many of the routines have a create new file failsafe already, they just needs to be condensed into a single logical process.

Still struggling with the new graphics library, and how to make it update the display reliably without crashing the system, or ripping off other tasks (which usually causes crashes too). There doesn't appear to be any kind of page memory for this display; and I've long past broken the upper limit of drawing at the speed of the main loop. It was torture (twenty versions of torture), just to get a stable intro screen with animated sound waveform. That yellow slime is the animated audio waveform over a very long time (the intro screen typically only runs a few seconds; not half a day like it did there).

I did forget to mention a few things in my previous rundown. This still needs a buzzer to be installed on one of the side cars. It also has a 240MHz clock which is double the original prototype's clock speed. Just this bare hardware is enough to perform all the functions required in one way or another. The buzzer and rotary encoder aren't required for operation or data collection (assuming an optical indicator instead of the buzzer is acceptable). Just today I hacked around the rotary encoder so I could control the menus with just the onboard buttons.

One thing I'm still trying to wrap my head around; is how to collect the gyro data, and write it to a file without impeding shot timing function. It may not even be possible, but it's worth a try... Even if that doesn't work out; I can run the same code as a different function off the main menu to record the barrel movement.

[DNP]

Man has skills

[Lane]

They say the third time is the charm. I have updated this thread twice before with stamina. None of that information is included here. Apparently there is a different time zone at play in terms of the erasure of yesterday's composition.

I'll try again with a rake and a spoon. Going to work on a metal case since those two parts (orange and white) have screws in the back.

Still need to be able to record 32k raw gyro readings to SRAM; but the chip's ready (see the "noise" in that recording as "proof"). Has built in programmable LPF and HPF for a reason... Still broken on the programming of the microcontroller in this case. Rocked it all weekend with the same result. Purchased two more of these to make sure it gets done. Yeah; can't post this without any kind of explanation.

So . noop. Pretty sure the earth is still spinning based on those gyro numbers... 

[Lane]

Weird; looks like I was able to save a previous message more than 24 hours? I thought I had posted an update; but it was here in the update window. Too many revisions to even consider posting the old update. BUT

Had some further thoughts about why this 21.750" might matter. Given a 1:1 relationship with barrel profile (which I have in this case); it might amount to the amount of extra whip that a longer barrel adds. Go too short; and accuracy is sacrificed. Go too long; and the barrel harmonics might change in an unfavorable way. Has anyone ever handled 10' or 20' black pipe? It does not act nearly as rigidly as a 3' length... I won't be convinced until I see raw data myself. So; the Shilen #7-HV contour may indeed get worse beyond 21.750"? Unfortunately we have so many other barrel profile options; that I can't see sticking to that barrel length as a standard for any other reason. OBT theory suggests barrel length is irrelevant in any frame of reference (profile, caliber, cartridge, etc.). I'm not sure that's sound reasoning either.

I'd be curious to hear any other opinions. Been trying to get the gyro data recordings up to speed; but nothing I've tried so far writes much faster than 1,000Hz to RAM. This is certainly a problem for the new hardware units coming in the mail. I'm going to need to work on a stripped down set of code and figure out why that's an issue. I've tried fiddling with every published register; yet nothing changes in terms of recorded samples. It is very strange that I'm recording duplicate samples though... So perhaps there is a way forward once I understand the constraints. 

That gyro is important because it gives me the ability to begin a field test. There are still a few things I absolutely need to see and test once I get up to speed. I'm thinking about a few options in terms of code profiling and debugging output. But I'm still not sure how to do any of that without breaking my existing run speed. Even dropping float math; those gryo numbers aren't any faster... Something is up here; just not sure what it is yet.

I've always kind of despised timer interrupts because of the complexity; but that's probably the ONLY way forward. Still not sure if I have to turn back off the RTOS to make it work...

[Lane]

Been a long time since I posted here. Have not needed anything in the mean time; yet still working on these projects. There was a technical problem or two with the superior shot timer hardware. Don't want to bore the masses; but I wish to be able to steadily record a rather large window of gyroscope data. There is but one single trace missing between the Inertial Measurement Unit and the CPU in this circuit board, which makes it's a hair too slow for that real time operation (SPI vs. I2C). The IMU buffer compounded by the RTOS timing; even a dual core CPU mean that I can't seem to collect the necessary 4ms of data (even 2ms could work in a pinch) with enough accuracy to publish results. Could I fix this with a total re-wire? Yes. Could it be fixed in a software re-write? Maybe. Have I finished, or even started that process? No. Not at all.

I am furthermore; still missing a functional (or tested) chronograph device to gauge projectile speeds. I've yet to see a single reading on my RCBS unit besides RCbS on the LCD, and a zero...

What made me think to post again, is a number of powder comparison charts that I've recently come across. I had long wondered where CFE BLK fell, and it was actually listed here; where it's not available in QuickLOAD as a reference point. Chuck Hawks also comes through with a few standard comparisons in this regard as well: https://www.chuckhawks.com/powder_relative_burn_rate.htm

Just finished the re-finishing of the wood stock on a muzzle loader build I started just about a year ago. (Different chart: http://www.curtrich.com/BPConversionSheet.htm) Figure it's time to get intimate with the volume vs. mass vs. burn rate vs. etc. among hand cast projectiles. Graphing all that barrel flex is still a goal in any barrel form; especially the 23.750" length barrel(s). As soon as I can certify any data points in a time window; I'll be glad to expound. Some black powder shooters want a projectile that always rocks at 100 grain charge (not 92, 93.5, or 95, etc.)?

Besides all of that; actual work has had me up against the wall. I've switched gears a few times, and even made some homemade black powder the other day. Been working towards a few other new builds as well; albeit much more slowly than in the past.

Burnrate_Chart_dt.pdf burnratecolor.pdf

[98Z5V]

For all my 300BLK loads, I'm running Accurate 1680 or Hodgdon H-110.  For my .30 Carbine, I'm running Hodgdon H-4227.   You find alot of similarities between 300BLK powders and .30 Cal M1 Carbine powders, when you start crossing them all over against each other.

[Lane]

Thanks for the tips here. A few more things for me to consider...

I've got the H-110 and H-4227 in stock already. Had been considering AA-1680 for a while but hadn't come across it at the local gun shops. That may change as one of my favorite shops is adding reloading supplies in addition to their standard offerings.  

Decided to double check those burn rate charts against reloading manuals; it does appear that using all four of those burn rate charts as comparison might be a bit sketchy. I went round robin and noted that 1680 should be basically the same as IMR 4198 (or H-4198), and CFE BLK is sequential with 1680 on one chart... But that's where it got dicey. Reloading data does not appear to prove out those comparisons at all. Especially so with heavy projectiles in the 300 Blackout load data. The most interesting thing was the pressure difference noted between CFE BLK and the 4198s, but there are likely other differences as well. Even IMR 4189 and H-4198 began to differ notably with the heaviest 300 Blackout projectiles (where they are quite similar is other loads). 

So; all in all, they make an interesting reference point, but can't be used for any kind of substitute comparison. Seems like every single one of those powders has unique properties in some way or another. Perhaps due to the bulk density that's not accounted for (among other things?)?

I don't currently have anything chambered in 7.62x33; though, I have been considering my options for another build. I've been leaning towards an M1 Garand or 1903 Springfield, but I could be swayed yet. I had a good time finishing wood on a muzzle loader, so I'm looking for something a bit different. Still have an AR-15 ready to build minus a barrel, so I'm not running away. Better still; Armalite has upper receivers in stock again, so I can push on a 260 Remington build when I secure that funding. 

Attached are prints I found for the M1 Garand; they seem reasonably complete. I also found an entire book detailing the 1903 but it's a bit too large to attach here; not too hard to find at the open library. https://ia802205.us.archive.org/10/items/unitedstatesrifl00colvrich/unitedstatesrifl00colvrich.pdf Can't seem to find any prints freely available for the M1 Carbine, but the M14 is of course common as well. 

m1plans.pdf M_14_Receiver_Ordnance_Prints.pdf

[Lane]

Done a bunch of hardware work in the circuit world over the past few months. I guess I'm ready to rewire these second generation units for the gyro recording speed now. It's a single wire job; just bridging a single pin on the IMU chip, to one pin on the MPU. That of course will require a few changes in the code; but should provide the data capture at the necessary speed for measuring barrel movement in real time (and writing it to a file for every shot). Might as well upgrade the battery in the process; but mass is going to need to be a calculation added (and calculated) once the device is strapped to the barrel. Less weight is better in terms of purity when measuring barrel movement.

Never a dull moment around here; but I do enjoy rotating projects as the time allows. Apparently "free time" is now available in heaping portions. Godspeed everyone.

[shooterrex]

https://kalikey.com/product/ar15-kali-key/

Lane saw this and thought of your project.