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Post by Richard on Dec 14, 2010 21:29:51 GMT -5
DISCUSSION THREAD CAN BE FOUND BY FOLLOWING THIS LINKYes, this is the looooooooooooooooong awaited TUESDAY  And boy was it mentally draining for a non-geek! OK, so I managed to get it going (See a cold winters day a CVWC on the Back Porch for pictures) and produce some Traces. There were minor complications but nothing major. Be very new, there is a lot to be learned about the instrument and computer. I need to learn how to name the traces and add notes with each trace. One thing you will notice on each trace..........there are a number of squiggly lines going across the bottom in different colors. There will be corresponding Traces listed in the upper right side of the window. These are low level traces caused by the movement of the gun and wire. Being a ML, is hard to avoid movement when getting the rifle from the rest to floor for cleaning and loading. If you are extremely careful, some can be avoided. So, when you read the trace just pick the numbers with PSI reading in excess of 20,000. It seems there is supposed to be a way to remove them in the lower right side of the window. I "unchecked" the mistakes, but when I "saved" the file, they still appeared there??? Edge???. Also, there is another weird occurrence on the saved traces...............I physically wrote down every PSI and velocity from my chrono. In looking at the files when I got home, I noticed that the PSI numbers were slightly different from those I viewed at the time of the shot?  ?? Not a whole lot, but everyone is different? Look at my log sheet and compare to the numbers in the upper right and you will see what I mean. The original reading might have been 28650 psi and it shows up as 29639 or something like that? There are none that differ by more than maybe 50psi or so......which is not a real big deal, I just don't know why? Since I have not run this past the Administrators, I left out load information for the Triplex loads. I fired two five shot groups with both saboted and sabot less 200 gr. bullets. All I can say is that a couple of the duplex loads are WAY higher and even those are not HIGH pressure. From what I observed today? Nothing I have shot so far in any of my ML's would have exceeded maybe..................35,000 psi......................With the exception of when I bulged my barrel So, here are the targets and work sheet and Pictures I took of the computer screen. I'm working on the file transfer from the lap top to my PC.........via Flash Drive. Richard        
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Post by deadon on Dec 14, 2010 22:01:13 GMT -5
I am 5'8" tall and this is soooooo far over my head. I do not understand any of it. Richard, you are the man for taking this on and Jon , God bless you too. Is there some way for you to say "this one is OK " or" this one is not OK" for us dummies. It may be that I am the only one here who would benefit from this elementary explanation so if its too much trouble, thats ok too ;D Rusty
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Post by spoonover on Dec 14, 2010 22:01:17 GMT -5
How many milliseconds before the bullet exits the barrel? Good for us you are learning, some how takes out some of the mystery of how this works.
I am proud of you Richard, thanks!
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Post by Richard on Dec 14, 2010 22:16:46 GMT -5
Each trace has a milli-second reading that can be brought up. As I recall, most were in the .4 or milli second range? Deadon.............I believe the administrators are feeling that under 40,000 psi would be a good place to stop.........even though higher is do-able. From my initial impression, I can't see the need for exceeding 35,000 psi. As far as the traces go, I believe the theory is that closer you can get each trace to overlap one another, the more accurate the load should be. Now that I have completed this much, I have to read further in the manual Richard |
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Post by edge on Dec 14, 2010 22:17:58 GMT -5
Those numbers seem very low! When you call up the trace does the barrel information look correct? Especially the ID and OD where the gage is attached. I traced a load for dave once and I'll see if I can find it. If you call up the trace to save the picture you need to uncheck the box and they won't show up. When you do a save it saves everything. You can delete the bad traces, but unchecking does not delete them, it just hides them. If the gage is in an easily accessible location you can detach it between shots and you won't get the false readings...just remember to reattach it before shooting  edge. |
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Post by chuck41 on Dec 14, 2010 22:20:43 GMT -5
Is there any kind of a calibration on that system? Comparing results to a known value and adjusting it accordingly to adjust the output of the strain gauge?
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Post by edge on Dec 14, 2010 22:33:51 GMT -5
Here is a load that I did for dave d. it was not as high as I had thought  62 grains of H4198 w a 195 BX in a harvester sabot...I don't remember if he gave me regular or crush rib. No chrono. I forgot to mention that this was with a LRM primer and not a 209 as I normally use!  edge. |
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Post by Richard on Dec 14, 2010 22:35:34 GMT -5
Edge........I have got to play a little more with it. I am finding out more as I explore different windows. Chuck.........Unfortunately, there is no calibration. What they have you do is compare your readings with a known "FACTORY CARTRIDGE"............Which in this case, we do not have Richard |
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Post by edge on Dec 14, 2010 22:35:40 GMT -5
I also suspect that you need to adjust the sensitivity. I think that it starts your time from sear release and that may be why there appears to be a delay.
edge.
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Post by rossman40 on Dec 14, 2010 23:19:55 GMT -5
Edge may be right on the sensitivity. Several charts show traces where if you adjusted the time they would match the others. Then you have traces that apparently no shot was made which could be just closing the bolt.
Usually the bullet is out of the barrel around the 1.0 millisecond mark.
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Post by deadon on Dec 14, 2010 23:25:15 GMT -5
Each trace has a milli-second reading that can be brought up. As I recall, most were in the .4 or milli second range? Deadon.............I believe the administrators are feeling that under 40,000 psi would be a good place to stop.........even though higher is do-able. From my initial impression, I can't see the need for exceeding 35,000 psi. As far as the traces go, I believe the theory is that closer you can get each trace to overlap one another, the more accurate the load should be. Now that I have completed this much, I have to read further in the manual Richard Thanks Richard, So as you explained ES ,the trace stuff can tell you something about accuracy also? Rusty PS maybe I should just call you instead of boring all these folks with my dumb a#$% questions. |
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Post by chuck41 on Dec 15, 2010 0:00:18 GMT -5
Edge........I have got to play a little more with it. I am finding out more as I explore different windows. Chuck.........Unfortunately, there is no calibration. What they have you do is compare your readings with a known "FACTORY CARTRIDGE"............Which in this case, we do not have Richard This is what I suspected. Many of the readings look a bit low to me but perhaps that is because I have most often seen 45 cal data with heavier bullets. Although you do not have "known" factory cartridge, you do have lots of reloading data for 45-70 cartridge rounds available right from Hogdon's web site. Straight sided case with a 45 cal bullet is about as close to the inner dimensions of your ML10 as you can hope to get. Your bullet is not fully engaged in the rifling so it should be a bit less pressure, but probably not an awful lot. For example Hogdon's data shows 59.5gr of H4198 behind a 300gr bullet to produce 37,300cup and 2300fps. A max load with that bullet of 63 grains behind that 300gr bullet produces 50,000cup with 2532fps. If you don't like the idea of shooting a 300gr bullet look at loads for the 45 Colt. If you have a bit of 4227 or Sr4756 lying around you can get a calibration load from that with a 200gr bullet as well. Unfortunately with those your calibration pressures will be pretty low but it will still give you a good idea of how close you are reading. If you try a few of those loads you should be able to calibrate that thing to a gnat's eyebrow even without a known "factory cartridge". |
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Post by esshup on Dec 15, 2010 0:21:31 GMT -5
I don't think there is any correlation that can be determined between CUP and PSI. i.e. there is no conversion chart to convert one to another.
I think the flatter the bell curve, the gentler the push on the sabot, so the velocity might be the same with less peak pressure because the bullet is seeing pressure for a longer time.
Richard, think of how long it took you to understand all the nuances to loading great rounds for 600 and 1000 yd competition. Look at PT that way, and don't get discouraged. It'll all fall into place sooner than you think!
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Post by Dave W on Dec 15, 2010 5:33:57 GMT -5
Sabotless 250 or 300gr bullets with H4198 should give close numbers to 450 Marlin data on Hodgdons site.
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Post by Jon on Dec 15, 2010 5:49:47 GMT -5
Richard. Great report as usual great start with the pressure trace. What is your impression? Was it informative to you and worth all the work you are putting into it?
Jon
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Post by tar12 on Dec 15, 2010 6:18:01 GMT -5
Excellent start! You have all winter! ;D
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Post by mike3132 on Dec 15, 2010 9:46:30 GMT -5
Richard,
We saw the same double spike with Lil Gun powder when RB was tracing pressures. I read once what cause that double spike but cant remember now. Anyone else remember? Mike
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Post by jeremylong on Dec 15, 2010 10:44:58 GMT -5
Mike even the second H4198 trace is showing a double bounce. I would bet it is the setup or wire etc.. Especially since the first trace does not show the bounce.
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Post by screwbolts on Dec 15, 2010 10:48:45 GMT -5
Hi Chuck 41:
I think your theory of 45/70 to the 45 ML has some merit, but very little in the aspect of Pressure. As you may be aware I shoot cast boolits, I shoot these in cartridge rifles also. The sizing and engraving of a J bullet into the rifling creates much more resistance and higher pressure than sizing and engraving a Cast boolit of the same weight, and of any lead alloy. IMHO there is no way in oops, that any projectile that can be loaded from the muzzle, will even begin to create the pressure of a projectile being sized and engraved as it enters the rifling. That is of coarse in regards to the same powder charge being used in all examples. It is just physically impossible IMO.
Ken Hall
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Post by Jed on Dec 15, 2010 11:01:00 GMT -5
Richard,
I suppose the simplest way to find a "standard" would be to look up some of the old information that RB had on the .50 and shoot some of those loads. If your info equals his (or close to it), when using the same powder charge, sabot, bullet, etc. you will then have a "known standard."
I think comparing your trace readings to his is probably more accurate than comparing them to the Hogdon data, for the reason screwbolts mentioned above.
Great job, though, and thanks for tackling this project!
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Post by pposey on Dec 15, 2010 11:10:22 GMT -5
Saboted or even sabotless loads should be way lower pressure than regular rifle loads, as said above we are not forcing a jacketed bullet into the bore like a centerfiore round
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Post by edge on Dec 15, 2010 11:44:20 GMT -5
Saboted or even sabotless loads should be way lower pressure than regular rifle loads, as said above we are not forcing a jacketed bullet into the bore like a centerfiore round Hence the use of a duplex load to artificially increase the initial pressure! I would agree that it is hard to get the slower powders to get up to pressure quickly in a ML. I can assure you that duplex will get you a trace that looks just like a centerfire trace  edge. |
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Post by chuck41 on Dec 15, 2010 13:22:27 GMT -5
Hi Chuck 41: I think your theory of 45/70 to the 45 ML has some merit, but very little in the aspect of Pressure. As you may be aware I shoot cast boolits, I shoot these in cartridge rifles also. The sizing and engraving of a J bullet into the rifling creates much more resistance and higher pressure than sizing and engraving a Cast boolit of the same weight, and of any lead alloy. IMHO there is no way in oops, that any projectile that can be loaded from the muzzle, will even begin to create the pressure of a projectile being sized and engraved as it enters the rifling. That is of coarse in regards to the same powder charge being used in all examples. It is just physically impossible IMO. Ken Hall Instead of using a wild guess on what appears to be "intuitively obvious", go actually look at the reloading data available to you. Pick a cartridge like the 45 ACP and compare the same loads with lead and XTPs of the same weight and the pressures measured. There is not much difference in the pressures actually achieved with the same loads between cast and jacketed "boolits" even though as you indicated the lead engraves much easier. Most are well under 5% with 2% or less on many pressure recordings. The engraving is done in the first tiny fraction of a millisecond considerably before max pressure is ever achieved. There will be some difference in pressure because of engraving just as I indicated in the original post, but percentage wise it will not be that great, especially with the use of duplex loads with slower powders to increase the initial pressure build to compensate for the pressure rise of engraving as edge noted. It would be a whole lot less error than the possible difference in depending on a completely uncalibrated system relying on a glued on strain gauge with only estimated values for several variables. Unfortunately most of RB's pressure readings were done with a 50 cal weapon. I don't remember him using a 45 in any of them and haven't seen any in the ones I looked up on the old board. Richard is using a 45 and there is a very large difference between pressures with similar loads between the two. My point is some calibration is better than no calibration. |
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Post by spaniel on Dec 15, 2010 14:29:45 GMT -5
If I am reading these posts correctly, using 62gr H4198 and a 195/200gr bullet edge and Richard's traces show either 20K or 30K psi? Both shot in a .45? That is a concerning discrepancy. Let's say Richard's is reading low for some reason (which we do not know to be the case!), perhaps his loads are hitting 43K and not 33K like they look?
This was the point I made about a control. Not that I have an answer on how to arrive at one, I'll leave that to the experts.
Thanks Richard, and keep up the good work!
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Post by ET on Dec 15, 2010 14:52:03 GMT -5
Richard, We saw the same double spike with Lil Gun powder when RB was tracing pressures. I read once what cause that double spike but cant remember now. Anyone else remember? Mike Mike3132 The so called secondary hump is a secondary pressure spike. If you scroll down to “Secondary Pressures” & “Catch Up Theory” this will provide a better explanation. www.shootingsoftware.com/barrel.htmEd |
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Post by Richard on Dec 15, 2010 15:19:27 GMT -5
OK, so look.............This being the very first time out for a non-geek type person, I was just happy to see some activity on the screen when I pulled the trigger ;D. I am more confident now that I have actually produced, what appears to be a trace, that I can better refine some of this stuff. So based on this raw information, don't go "hanging your hat" on it ;D However I will say this: Since all the traces were performed under the same criteria, if you look at the triplex graph and compare it to the other duplex and single loads, it is definitely much lower. That load consisted of 65 gr. total weight of powder. Nothing scary!
I would also go along with the theory that a load stuffed down the muzzle with no throat to engrave a bullet, will produce much less pressure than a cartridge rifle with a throat.
Thanks for all the encouragement and I look forward to doing more work and refining the results.
Richard
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Post by edge on Dec 15, 2010 16:16:38 GMT -5
Richard, You might be able to set it up without a load in and pull the trigger and see if that triggers the device. If it does move up to another setting until it stops triggering. I used to disconnect the gage while I loaded, but then you need to ensure that the unit is ready and reading the correct barrel I think. I might suggest that you send Jim an email and include some of the traces. What setting you should have the sensitivity on to exclude the false triggering I don't know but I bet that he might be able to suggest one. He is only an email away and very willing to help. He always has gotten back to me in less than a day. rsi@commspeed.netedge. |
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Post by stubblejumper on Dec 15, 2010 16:28:21 GMT -5
"The so called secondary hump is a secondary pressure spike"
ET
I posted this previously on the board with a couple of questions but no one replied to it. If these are real pressure spikes they should be a cause for concern in certain loads such as the examples given on their website as they can be very substantial.
Richard
Keep up the good work, your effort is truly appreciated.
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Post by Dave W on Dec 15, 2010 16:31:47 GMT -5
I have shot sabotless loads with the 300SST and H4198 that surpass Hodgdon 45/70 loads velocities, and right at 450 Marlin data with 250gr bullets. RB posted he was getting speeds same as 450 Marlin data for 300's and 250's.
Swinglock and Richards Customs are shooting similar charge weights to a .458 Mag at higher pressures without throat engraving.
The 62gr H4198 load was blowing sabots for many. How could a 23k psi load blow sabots, radiused bullet bases or not? Isn't 23k psi lower than BP sub pressures?
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Post by ET on Dec 15, 2010 16:49:08 GMT -5
"The so called secondary hump is a secondary pressure spike" ET I posted this previously on the board with a couple of questions but no one replied to it. If these are real pressure spikes they should be a cause for concern in certain loads such as the examples given on their website as they can be very substantial. Richard Keep up the good work, your effort is truly appreciated. Stubblejumper The answer to Mike’s question I came across this morning while brushing up again on the pressure trace unit from RSI. This is why my answer is forth coming now. And yes that secondary pressure spike should be closely monitored from what I interpreted that was conveyed in the article. Yep it’s an eye opener for sure. Ed |
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And boy was it mentally draining for a non-geek!
?? Not a whole lot, but everyone is different? Look at my log sheet and compare to the numbers in the upper right and you will see what I mean. The original reading might have been 28650 psi and it shows up as 29639 or something like that? There are none that differ by more than maybe 50psi or so......which is not a real big deal, I just don't know why? 
