jackie schmidt
New member
Anybody taken a good look at my tuners. The feature a rubber dampener, some call it a snubber.
I dare not mention that I was the first to use this, I do not want to get stomped on like I was in the thread on Tuners, but some very prominant shooters have now copied the concept.......jackie
I dare not mention that I was the first to use this, I do not want to get stomped on like I was in the thread on Tuners, but some very prominant shooters have now copied the concept.......jackie
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Vern
Morethan1waytoskinacat
Yep seems I saw someone stomping someone else on the rimfire boards about noodles, and rubber washers or bushings.
Cuz dont let them knock you down. Sometimes multiple people think about the same thing at the same time but one makes it out first.
Telephone for example.
Cuz dont let them knock you down. Sometimes multiple people think about the same thing at the same time but one makes it out first.
Telephone for example.
Boyd Allen
Active member
The commercial product that was referred to in the previous post, is made by Sims Vibration Labratory. Here is a link to the product. http://www.limbsaver.com/2011/firearms/41.php
Back when they were first introduced, they were called Deresonators. After reading about the first ones, that had a 5/8" ID, I was curious enough to call the mfg. and suggest that they make one that had a larger ID, for varmint and target weight barrels. Some time later, they sent me two prototypes that have 3/4" IDs. The rubber is quite gummy and stretchy. I have stretched one of them over a tuner that measures 1.25". If you tap a free floated benchrest barrel, with a small wrench and compare the sound with the same barrel that has one of the Sims rubber doughnuts mounted, the difference is quite noticeable. In the latter case, it is a dull thud of rather short duration. These units are inexpensive and widely available. Midway carries them. If you look at the article, in the Guns of the Week section, about Joe Fredrich's Rimfire rifle, you will see that in addition to a rather weighty tuner, his barrel has one of the Sims units, a couple of inches in front of the stock. http://www.6mmbr.com/gunweek078.html I eventually found that mine worked best (on a 10.5# 6PPC) 2" back from the muzzle, just behind the tuner that Jackie gave me (pre rubber and brass model). I have no doubt that the combination, with a little adjustment, made the barrel shoot better. It was one that I had shot quit a lot before putting the tuner on it. Their combined weight was about 5 1/4 oz.
Back when they were first introduced, they were called Deresonators. After reading about the first ones, that had a 5/8" ID, I was curious enough to call the mfg. and suggest that they make one that had a larger ID, for varmint and target weight barrels. Some time later, they sent me two prototypes that have 3/4" IDs. The rubber is quite gummy and stretchy. I have stretched one of them over a tuner that measures 1.25". If you tap a free floated benchrest barrel, with a small wrench and compare the sound with the same barrel that has one of the Sims rubber doughnuts mounted, the difference is quite noticeable. In the latter case, it is a dull thud of rather short duration. These units are inexpensive and widely available. Midway carries them. If you look at the article, in the Guns of the Week section, about Joe Fredrich's Rimfire rifle, you will see that in addition to a rather weighty tuner, his barrel has one of the Sims units, a couple of inches in front of the stock. http://www.6mmbr.com/gunweek078.html I eventually found that mine worked best (on a 10.5# 6PPC) 2" back from the muzzle, just behind the tuner that Jackie gave me (pre rubber and brass model). I have no doubt that the combination, with a little adjustment, made the barrel shoot better. It was one that I had shot quit a lot before putting the tuner on it. Their combined weight was about 5 1/4 oz.
4
4Mesh
Guest
Thanks Boyd, that's exactly what I was thinking of.
Grouping... As Harold Vaughn probably would have said, there is clearly a change, but isolating the group size portion of it in so many other variables is very difficult.
If it made things better, it was slight, but there wasn't a lot of room for improvement. It didn't make anything worse, and I'm pretty sure that would have been obvious.
I won't make any claims as to "work" or "not work". I will guarantee you they do "something" and it is very easily visible on a 1K target. There is a significant change in POI. I'll allow others to speculate as to why that is but I have seen it.
Grouping... As Harold Vaughn probably would have said, there is clearly a change, but isolating the group size portion of it in so many other variables is very difficult.
If it made things better, it was slight, but there wasn't a lot of room for improvement. It didn't make anything worse, and I'm pretty sure that would have been obvious.
J
JohnsonGunsmith
Guest
4 Mesh
No programming experience at all.
No electronics experience.
This does interest me enough to learn how to make this all work.
I do not know what the learning curve will be but I am smart enough to figure things out and have always been pretty curious as to how things work from childhood.
I do not think you are implying this is impossible or even unlikely. I think you are saying the opposite that it is possible and that I should try it if I will commit to it and am willing to learn.
I will quickly spend $400 to see if there is the possibility of success.
as for the tools I only own the last 3 in the list. Mill, lathe and drill press. as far as being computer savvy I can do only the typical stuff most people do. When I have a problem I usually call a friend but I know a guy who is pretty good with computers. I have a finite amount of time as I am sure most people do and I would like to make up for some time by spending a bit extra but I am not afraid of work and am willing to do this on a budget in order to get some testing completed.
Thanks for all your help
Brandon J.
No programming experience at all.
No electronics experience.
This does interest me enough to learn how to make this all work.
I do not know what the learning curve will be but I am smart enough to figure things out and have always been pretty curious as to how things work from childhood.
I do not think you are implying this is impossible or even unlikely. I think you are saying the opposite that it is possible and that I should try it if I will commit to it and am willing to learn.
I will quickly spend $400 to see if there is the possibility of success.
as for the tools I only own the last 3 in the list. Mill, lathe and drill press. as far as being computer savvy I can do only the typical stuff most people do. When I have a problem I usually call a friend but I know a guy who is pretty good with computers. I have a finite amount of time as I am sure most people do and I would like to make up for some time by spending a bit extra but I am not afraid of work and am willing to do this on a budget in order to get some testing completed.
Thanks for all your help
Brandon J.
dennisinaz
New member
I have a Rem Mtn rifle that I had blue-printed by one of the big-name accuracy gunsmiths as an experiment to see exactly what would be gained over a stock rifle. I had a Krieger barrel installed with a fairly tight reamer. My accuracy was still nothing too interesting, even after a second barrel was installed (Hart first, then Krieger-which shot much better than Hart).
On a whim, I put a Limb-Saver barrel De-Resonator on it and slid it up to within a few mm of the forend. This actually made a noticeable difference. It is on very tight, doesn't move even in brush and makes it possible to shoot several weights of bullets to similar points of impact. Although I got mine free at the SHOT as a demo, they only cost about $10 and are worth playing with. They look a little dorky, but seem to be of some real value; at least on a thin barrel contour like this.
4
4Mesh
Guest
Wonderful. Yes you are correct, I am not saying it is impossible, it is quite possible. And with some time, you WILL learn stuff about what happens to that gun when it goes bang, even if everything goes wrong.
You have the mill / lathe and drill press. You're in business. This other stuff is cheap.
Ok, 8 years ago I would have said that programming would have been easier to learn back in the 70's or 80's on something no longer available to buy. That has changed, and now I would absolutely advocate that little gizmo I posted the link to. Not only will it be so damn much fun you won't believe it, but it's as easy and as straightforward as programming is going to get. And, it doesn't cost an arm and a leg. I recommend that device since it has good resale value, and allows you a learning and debugging experience that you will never get on a PC. Any more, PC's suck for learning to do programming. At the beginner level anyway. It isn't that programming is difficult, but, nothing today is documented AT ALL, and you are google searching all the time to find every tidbit of information. That company there produces datasheets just like the old days. Yes, that datasheet for the processor thats included on the board is 1000 pages. But the info is in there. You don't need to find some obscure website to get info. And it's not like you need to read every single page and every word. You need to know the basics of each section that pertain to you, and you need deeper information when things don't work as expected. But the info is there, and its easy to find.
Your accelerometer is just one way to collect data. But like almost all methods, it's an analog device. Meaning, it will give you voltages between 0-5Vdc as a result. You need to catch those really fast, and you need to catch them as a number (Analog to Digital Conversion ADC). An oscilloscope is the easiest way. However, in some cases, it is not the best way. It sure is nice to have a scope for all the work on the circuits, and it doesn't have to be the fastest thing in the world. But when I did this, I did not collect usable data nearly as well with a scope as I did with a processor. I also didn't use an accelerometer, though I'd probably use a few now if I was to do it over again. I made my own devices. Be that as it may, you'll need to try all ways before it's all over. That 18Fxxx chip on those boards I linked has A-D converters on it. You simply set them up and read the values from ram. Easy as pie. The controller I'm working on right now will do 5 at one time, and sample them >1,000,000 times a second. For a small controller, that's unheard of. My chips were <$5 each. Fyi, I have no use for the A-D on them. It just happens to come with it, as it does many other things. That same chip is sold with more pins and will sample 9 simultaneous A-D's. at that speed, you would be able to have 4 2-axis samples simultaneously (4 sets of sensors on the barrel at the same time), and with a typical bullet ride of 2ms, lets say conservatively you could sample those 2400 times while the bullet is in the barrel. So, a super fast scope really not only isn't necessary, but, isn't going to give you this level of data collection cause this data you can actually get out of the chip and save, then move to excel or a database if you wanted to.
I would be willing to point you in the right directions (or what I think are right) but I will not do the work for you and will tell you that up front. I don't have time to invest. But I'd be happy to offer ideas as time permits. And I can give you shopping ideas that'll really help keep the cost down and fun factor up. Fun being what this is all about anyhow!
As long as you don't get discouraged, you'll find this a great experience. There's various forums full of folks who'll help with about any problem.
In the interest of not starting some flame war, I'd suggest we move this from the forum to email. Mines in my profile I think...
A scope will have a limited number of inputs. One of your inputs will be used just to tell the thing when to catch data. That is one limitation. Scopes with 4 channels or more are expensive. Scopes >100Mhz start to get expensive too. This is why your buddy said it would be an expensive undertaking. You don't need a super expensive scope, and that is why I say get a used one cheap. It might not have todays features, but people have built some pretty kewl stuff with scopes of 20 years ago. Many can be had because they are no longer young enough to be certified. They are essentially scrap to the company that is using them where they need certification with paper to back it up. It has nothing to do with them not working, it just means that nobody will stake their life that the numbers from it are dead on correct.
If you go to microchip.com, you can go TODAY and download FOR FREE, Mplab8.70. That software will allow you to simulate any processor they make, and actually run the code and sample apps, as well as pretend there is actually a device there connected to sensors and all sorts of crap, all within an integrated development environment (IDE - Program for making programs let's say). You can do that for $0.00 tonight. The new IDE is under development and that is what I use right now. I'm working on a project at the moment using a brand new type of processor (to me, not that old to anyone else really) and using the new IDE in its current Pre-release state and I love it. It will not simulate like the old Mplab will though. And for that 18F chip, it may be easier to begin with what already works.
I'll tell you this as incentive. I have personally gotten about a half dozen people started in micro-controller apps, all of whom have had virtually 0 prior experience with the stuff. Each has gone on to do projects of their own with 0 help from me or anyone else, and the stuff has worked for what they do. People from all age categories 15-60, but all folks like yourself who will stick their nose to the grindstone and learn the stuff.
Begin by making an LED flash on that board. From there, you'd be surprised how close you are to reading movement of barrels.
You have the mill / lathe and drill press. You're in business. This other stuff is cheap.
Ok, 8 years ago I would have said that programming would have been easier to learn back in the 70's or 80's on something no longer available to buy. That has changed, and now I would absolutely advocate that little gizmo I posted the link to. Not only will it be so damn much fun you won't believe it, but it's as easy and as straightforward as programming is going to get. And, it doesn't cost an arm and a leg. I recommend that device since it has good resale value, and allows you a learning and debugging experience that you will never get on a PC. Any more, PC's suck for learning to do programming. At the beginner level anyway. It isn't that programming is difficult, but, nothing today is documented AT ALL, and you are google searching all the time to find every tidbit of information. That company there produces datasheets just like the old days. Yes, that datasheet for the processor thats included on the board is 1000 pages. But the info is in there. You don't need to find some obscure website to get info. And it's not like you need to read every single page and every word. You need to know the basics of each section that pertain to you, and you need deeper information when things don't work as expected. But the info is there, and its easy to find.
Your accelerometer is just one way to collect data. But like almost all methods, it's an analog device. Meaning, it will give you voltages between 0-5Vdc as a result. You need to catch those really fast, and you need to catch them as a number (Analog to Digital Conversion ADC). An oscilloscope is the easiest way. However, in some cases, it is not the best way. It sure is nice to have a scope for all the work on the circuits, and it doesn't have to be the fastest thing in the world. But when I did this, I did not collect usable data nearly as well with a scope as I did with a processor. I also didn't use an accelerometer, though I'd probably use a few now if I was to do it over again. I made my own devices. Be that as it may, you'll need to try all ways before it's all over. That 18Fxxx chip on those boards I linked has A-D converters on it. You simply set them up and read the values from ram. Easy as pie. The controller I'm working on right now will do 5 at one time, and sample them >1,000,000 times a second. For a small controller, that's unheard of. My chips were <$5 each. Fyi, I have no use for the A-D on them. It just happens to come with it, as it does many other things. That same chip is sold with more pins and will sample 9 simultaneous A-D's. at that speed, you would be able to have 4 2-axis samples simultaneously (4 sets of sensors on the barrel at the same time), and with a typical bullet ride of 2ms, lets say conservatively you could sample those 2400 times while the bullet is in the barrel. So, a super fast scope really not only isn't necessary, but, isn't going to give you this level of data collection cause this data you can actually get out of the chip and save, then move to excel or a database if you wanted to.
I would be willing to point you in the right directions (or what I think are right) but I will not do the work for you and will tell you that up front. I don't have time to invest. But I'd be happy to offer ideas as time permits. And I can give you shopping ideas that'll really help keep the cost down and fun factor up. Fun being what this is all about anyhow!
As long as you don't get discouraged, you'll find this a great experience. There's various forums full of folks who'll help with about any problem.
In the interest of not starting some flame war, I'd suggest we move this from the forum to email. Mines in my profile I think...
A scope will have a limited number of inputs. One of your inputs will be used just to tell the thing when to catch data. That is one limitation. Scopes with 4 channels or more are expensive. Scopes >100Mhz start to get expensive too. This is why your buddy said it would be an expensive undertaking. You don't need a super expensive scope, and that is why I say get a used one cheap. It might not have todays features, but people have built some pretty kewl stuff with scopes of 20 years ago. Many can be had because they are no longer young enough to be certified. They are essentially scrap to the company that is using them where they need certification with paper to back it up. It has nothing to do with them not working, it just means that nobody will stake their life that the numbers from it are dead on correct.
If you go to microchip.com, you can go TODAY and download FOR FREE, Mplab8.70. That software will allow you to simulate any processor they make, and actually run the code and sample apps, as well as pretend there is actually a device there connected to sensors and all sorts of crap, all within an integrated development environment (IDE - Program for making programs let's say). You can do that for $0.00 tonight. The new IDE is under development and that is what I use right now. I'm working on a project at the moment using a brand new type of processor (to me, not that old to anyone else really) and using the new IDE in its current Pre-release state and I love it. It will not simulate like the old Mplab will though. And for that 18F chip, it may be easier to begin with what already works.
I'll tell you this as incentive. I have personally gotten about a half dozen people started in micro-controller apps, all of whom have had virtually 0 prior experience with the stuff. Each has gone on to do projects of their own with 0 help from me or anyone else, and the stuff has worked for what they do. People from all age categories 15-60, but all folks like yourself who will stick their nose to the grindstone and learn the stuff.
Begin by making an LED flash on that board. From there, you'd be surprised how close you are to reading movement of barrels.
4
4Mesh
Guest
I should also mention that as of last year, C Compilers for those chips (lite licenses) are available for free and that means you can now program those chips in the exact same language you use for programming your PC. And the compilers for your PC are free too. Now, this is NOT Basic, so, it's not 'quite' as simple as that. But is is fast, and basic is certainly not fast. C is fast... fast fast...
Hi Brandon,
4mesh is correct, putting together the equipment for good firearm vibrational analysis can be done for well under $2,000..................but requires a particular skill set readily proficient in electronics, mechanical vibration analysis, experiment developement and analysis, advanced firearm functioning, etc..
The few people that I know that are capable of providing assistance are somewhat reluctant to do so due to the complexity of the subject matter and the commitment that it takes to follow thru......................simply put, most individuals lose interest in face of the amount of effort that would be required.
My suggestion would be to duplicate some of Vaughns' equipment/experiments first; simple band pass filters, integrators, and accelerometers, and procure an inexpensive oscilliscope, then mirror some of Vaughns' experiments. This will be a good first step in seeing just how far you want to take this and provide an entry level of experience to learn the language, equipment, and scope of the task at hand in order to take the next step, all for less than $500.
Once you have acquired this basic level of knowledge and proficiency you will be able ask specific questions about equipment upgrades and vibration analysis that can be answered on these messageboards..................Don
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I have Deresanators the full lenght of my heavy gun, that is were 4Mesh seen them. They work on that rifle, I've won a lot of score matches in the wind with it, I call it my wind gun. Tried them on my wife rifle,but did not see an improvement in accuracy because the rifle shot so well to begin with. I belive some are vibration sensitive some are not,you're only going to tweak so much out of a good shooting rifle or barrel. Now the bad one's you can improve.
Joe Salt
Joe Salt
F
frwillia
Guest
Reading to catch up on this thread a quote from one of my engineering co-workers drifted through my head and caused me to chuckle a bit - so thought I'd share it:
"Everybody believes an analysis, except the guy that did it. Nobody believes a test, except the guy that did it."
Fitch
"Everybody believes an analysis, except the guy that did it. Nobody believes a test, except the guy that did it."
Fitch
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I tried to passively capture muzzle movement on a 16.5lb br gun off a rest(1st attempt -FAIL).
This was using a laser mic, modified Oehler optical sensor, DAS, software/Laptop, precision mounting, etc(several $thou, nicely built FAILURE).
Some things learned so far:
1. Recoil invalidates everything
2. However fast & fine your resolution -AIN'T ENOUGH
3. This will not be cheap
It might not even relate to your endeavor. Just throwin in what I can.
This was using a laser mic, modified Oehler optical sensor, DAS, software/Laptop, precision mounting, etc(several $thou, nicely built FAILURE).
Some things learned so far:
1. Recoil invalidates everything
2. However fast & fine your resolution -AIN'T ENOUGH
3. This will not be cheap
It might not even relate to your endeavor. Just throwin in what I can.
4
4Mesh
Guest
That's pretty profound, good one.
Having always believed that anyone can do anything, I came up with a saying for nay-sayers long ago that goes like this.
Prit near everyone I ever saw who does something, when they did it for the first time, they'd never done it before.
In other words, people have no divine grace. If they can learn it, so can anyone else. Experience is obtained by getting experience. You also don't need to have someone spoon feed you data in order to learn something. The first person to discover anything did so without being shown by someone else, and so can you. School is not about learning, it's about learning how to learn.
Mikecr, did you give up after that? Had you considered that the data you wanted was in what you collected, but just wasn't obvious? Mhz isn't enough resolution? How fast do you think a barrel can vibrate mechanically? I agree, recoil's a B****. But, you might also consider that vibrations are predictable to a degree, so you don't need to take the reading while it's recoiling... You can back into what it used to be (if you want to)
Viewing(like with an oscope) should be easy, but recording is tougher. I just revisited my DAS and see that it's not as high in recording speed as I had thought. It samples at 14Kb/sec, which only provides 1.1K samples(defined) per second and a USB throughput into my spreadsheet table at only 240hz. Way too slow..
I could upgrade to 4.8K samples/sec capture software for ~$200 (keeping same hardware). But I don't know yet if that would be fast enough. I also need to point my laser mic at a dremel and watch it's output with a scope. Maybe it's not quick enough, and maybe it's 1thou resolution don't get it.
My objective was to record muzzle movement and position at bullet release. I wanted to see the differences between tuned and out of tune, and really only expected to 'see' where the muzzle was pointed -in only the vertical axis. I didn't foresee this all being so fast though.
Given the recoil, and in hindsight, my passive measure may not be a sound approach.
The field barrel doesn't just move up/down, but backward and side to side.
And lacking the resolution needed anyway, all I saw was some crazy recoil itself.
With better resolution, I will still need to subtract or normalize this recoil in my graphs..
It was ~6mos ago when I tried it, and I haven't gone back to it since(busy elsewhere).
I'll go at it again before the year's out, so I'm very intersted in this discussion.
Here is a relatively inexpensive "Vibrations for Dummies" universal laboratory kit (complete reference and support information data included) for around $180 and along with a $300 multi channel oscilliscope will get an individual well into the analysis of gun barrel vibrations, without having to build alot of the sensors, circuits, accelerometers, and other components that Vaughn had to develope in his efforts.............Don
see pg. 22/23 "Vibrations/Accelerometer design kit"
http://apps.meas-spec.com/myMeas/MEAS_download/Catalogs/Piezo/Piezo_Product_Guide.pdf
http://parts.digikey.com/1/parts/955190-sensor-piezo-film-design-kit-0-1004308-0.html
see pg. 22/23 "Vibrations/Accelerometer design kit"
http://apps.meas-spec.com/myMeas/MEAS_download/Catalogs/Piezo/Piezo_Product_Guide.pdf
http://parts.digikey.com/1/parts/955190-sensor-piezo-film-design-kit-0-1004308-0.html
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Vern
Morethan1waytoskinacat
Mike I want to try and ask this in such a way so as not to allow the thread to be hijacked.
There have been several threads in the past where recoil, time and distance was discussed.
However I never once saw anything other than math for answers. For a basic lets say ppc or pick any other caliber.
1. How much time elapses from primer ignition and the bullet leaving an average barrel.
2. How much has the gun moved in a rearward direction due to recoil before the bullet leaves the barrel.
Rather than everyone start throwing in "depends on the variations, caliber etc etc.
Give me some kind of generalized answer..... appprooooox ? milisecs approooooxxxxx 1/4" recoil,,,2" recoil just some small idea is all I ask.
Thanks
There have been several threads in the past where recoil, time and distance was discussed.
However I never once saw anything other than math for answers. For a basic lets say ppc or pick any other caliber.
1. How much time elapses from primer ignition and the bullet leaving an average barrel.
2. How much has the gun moved in a rearward direction due to recoil before the bullet leaves the barrel.
Rather than everyone start throwing in "depends on the variations, caliber etc etc.
Give me some kind of generalized answer..... appprooooox ? milisecs approooooxxxxx 1/4" recoil,,,2" recoil just some small idea is all I ask.
Thanks
4
4Mesh
Guest
Vern,
As you'd figure, the numbers vary by what rifle..
using numbers from a 30 Cal WSM 16.5# light gun with a 210 bullet at 2850fps, the numbers would be around .050" and closer to 2ms duration.
Mike, yes, it sounds like you were seriously handicapped with the speed at which you took the measurements. Again, that's sorta why I say a scope isn't always best for catching that stuff. It happens I have a pretty nice one. 8 channels @ 1.5Ghz, storage pre, post, whatever. Trouble with that is, A, I don't really like taking it outside. B, it is very temp sensitive so it spends all it's time re-calibrating if it sees the sun, C, exporting converted values ain't its strength. Truth be told, the input devices don't have bandwidth of that level anyhow so catching extra values is kidding myself. So, it goes back to using a controller to catch the numbers, and they are getting faster by the day. I looked up the datasheet on the chip I linked above on that proto-board and it runs at 64Mhz (16mips), has 13 A-D converters. It's probably capable of 20x the real resolution you were seeing, and again, there are much better choices still. For catching a lot of data, a super fast microcontroller is a better choice. Yes, they are a LOT more work than hooking up a probe, but, you get usable data.
As you'd figure, the numbers vary by what rifle..
using numbers from a 30 Cal WSM 16.5# light gun with a 210 bullet at 2850fps, the numbers would be around .050" and closer to 2ms duration.
Mike, yes, it sounds like you were seriously handicapped with the speed at which you took the measurements. Again, that's sorta why I say a scope isn't always best for catching that stuff. It happens I have a pretty nice one. 8 channels @ 1.5Ghz, storage pre, post, whatever. Trouble with that is, A, I don't really like taking it outside. B, it is very temp sensitive so it spends all it's time re-calibrating if it sees the sun, C, exporting converted values ain't its strength. Truth be told, the input devices don't have bandwidth of that level anyhow so catching extra values is kidding myself. So, it goes back to using a controller to catch the numbers, and they are getting faster by the day. I looked up the datasheet on the chip I linked above on that proto-board and it runs at 64Mhz (16mips), has 13 A-D converters. It's probably capable of 20x the real resolution you were seeing, and again, there are much better choices still. For catching a lot of data, a super fast microcontroller is a better choice. Yes, they are a LOT more work than hooking up a probe, but, you get usable data.