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Post by TGinPA on Jan 24, 2011 15:42:36 GMT -5
Pressure Trace and Velocity Comparison PacNor 45 Recessed Plug v. Savage Plug: Today I tested the same duplex load (N110/H322 15/55 200xtp) I tested and posted on 1/22, this time using a standard savage breech plug. I chose to test a duplex load because I thought that the geometry of the recessed plug theoretically might favor more consistent ignition of the booster and perhaps more consistent velocities and pressures. Velocities were virtually identical to what I saw on 1/22 with the recessed plug, but peak pressures were a bit higher. In both cases, pressures were consistent and reproducible. My take on this is that for duplex loads, a recessed plug probably doesn’t make any significant difference over the standard Savage plug, at least under the conditions in which this test was conducted. The load tested seemed safe in my gun but may not be in other conditions. Computer: Dell Inspiron Mini Notebook Gage and Module Manufacturer = RSI USB model Trigger Sensitivity = 5 Strain Gage Voltage = 4.9 Gage Factor =2.1 PSI Correction Factor: None Barrel Temp = 58-60 degrees F measured at the sensor (IR). Rifle Stand: Caldwell Lead Sled Altitude: 450 ft Temp 25 degrees F Sunny Chronograph: Chrony Alpha Model Barrel Type: PacNor .45 Cal Muzzleloader Length: 23in. from breech plug face Breech Plug: Savage (screw-in ventliner) Ventliner orifice: .031 in. Barrel OD = 1.055 in Barrel ID = .454 Bullet Diam.= .450 Bullet Type = Hornady 10 mm 200gr. xtp Bullet weight = 200 gr. unknurled Sabot: Harvester Light Blue Powder: N110/H322 15/55 gr. Primer :Fed 209 Shot fm clean barrel, 1 patch Bore Shine, 1 dry patch
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Post by dave d. on Jan 24, 2011 16:29:30 GMT -5
:)more pressure traces now this is getting interesting. Great work tg keep them coming.
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Post by Savage Shooter on Jan 24, 2011 16:37:39 GMT -5
Was this loading 13/55 as in the notes or 15/55 as noted on the trace?
Also I wonder what that secondary spike would mean to 26" barrel??
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Post by TGinPA on Jan 24, 2011 17:30:33 GMT -5
SS: 15/55. The post has been modified. In response to your 2nd question, a better man than I will have to answer that one. I have more on the effect of mixing powder rather than layering it in a duplex. With the previous smoke and fire that subject created, I am still debating whether to post it. TGinPA
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Post by Savage Shooter on Jan 24, 2011 20:01:53 GMT -5
SS: 15/55. The post has been modified. In response to your 2nd question, a better man than I will have to answer that one. I have more on the effect of mixing powder rather than layering it in a duplex. With the previous smoke and fire that subject created, I am still debating whether to post it. TGinPA I agree, have seen a lot of PT's and this is new to me, kinda concerns me. And it shows up on yours and Richards both, so IMO it means something, but what I have no idea,,,,, at the moment.... but it has had me head scratching.
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Post by Richard on Jan 24, 2011 21:22:03 GMT -5
Dang...........I still can't get those OBT marker to show up??? I got the bullet diameter in there and the barrel length from the bullet shoulder to the muzzle??? I also don't see a whole lot of difference in the two breech plugs Richard
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Post by pposey on Jan 25, 2011 8:35:08 GMT -5
How about a trace on some mixed not layered loads with the same powder,, be great to compare
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Post by craigf on Jan 25, 2011 9:50:08 GMT -5
How about a trace on some mixed not layered loads with the same powder,, be great to compare I am pretty sure that Richard tried that for safety concerns and there was no significantly different pressures.
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Post by TGinPA on Jan 25, 2011 10:37:23 GMT -5
PN 45 Duplex Loads: Mixing v. Layering on Pressure Trace and Velocity In past threads, the question as to whether duplex loads should be layered or can they be mixed has been addressed. When I searched old posts using the term “mixing powders” it was clear to me that this subject has created strong feelings on all sides. Had I done my search before my test, I might not have proceeded with what I did. In any event, having done it, perhaps others can learn something from it because it does supply some pressure data on the effect of mixing v. layering of a previously tested duplex load in a PacNor 45 cal barrel. On 1-22, I tested a duplex load which gave extremely consistent velocity and pressure curves. On 1/24, for comparison, I tested the same load, only with mixing rather than layering the powder in the barrel. Mixing was accomplished by placing the measured components in a small metal dish and pouring the mixture back and forth into a second metal dish ten times and then loading it through a funnel and then testing the load ,measuring both pressure and velocity. What I found was that the mixed version of the duplex load gave widely inconsistent peak pressures. Velocity variance was not as inconsistent At least with this duplex load, under the conditions present on 1/24, mixing of these powders markedly deteriorated performance of this load in terms of pressure and velocity consistency when compared to layering in a previously tested duplex load. The warning here is that this is a very small piece of info on one specific duplex load. Certain ammunition manufacturers have clearly shown that some powder blends can produce superior results. The powders I tested on 1/24 are relatively large grained and differ physically. Maybe mixing of finer grained powders of similar physical characteristics might have promoted more even mixing to improve consistency. This load seemed safe in my gun but may not be under other conditions. Computer: Dell Inspiron Mini Notebook Gage and Module Manufacturer = RSI USB model Trigger Sensitivity = 5 Strain Gage Voltage = 4.9 Gage Factor =2.1 PSI Correction Factor: None Barrel Temp = 59-62 degrees F measured at the sensor (IR). Rifle Stand: Caldwell Lead Sled Altitude: 450 ft T= 25 degrees Sunny Chronograph: Chrony Alpha Model Barrel Type: PacNor .45 Cal Muzzleloader Breech Plug: Pa Machine Recessed (screw-in ventliner) Ventliner orifice:.033 in. Barrel OD = 1.055 in Barrel ID = .454 Bullet Diam.= .450 Bullet Type = Hornady 10 mm 200gr. xtp Bullet weight = 200 gr. unknurled Sabot: Harvester Light Blue Powder: N110/H322 15/55 gr. Primer: Fed 209 Shot fm clean barrel, 1 patch Bore Shine, 1 dry patch
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Post by bob64 on Jan 25, 2011 11:07:41 GMT -5
Thanks to you and Richard for this very informative and interesting project. The question I have, as I look over the blended duplex loads, is "can the velocity between trace loads be so close when the pressure and areas under the curve are so widely different?"
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Post by Savage Shooter on Jan 25, 2011 11:09:46 GMT -5
This is correct, when testing duplex thru the .50 but with out any pressure info, it became quickly apparent that velocity ES went way up. Also noted accuracy not as good.
Mixing = bad but does not APPEAR to be dangerous, of course appearance can be deceiving.
Layering = good consistent velocities, lower ES etc.
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Post by TGinPA on Jan 25, 2011 11:20:27 GMT -5
bob64: Good question. Makes you wonder what we are measuring. But, unless I can see a clear reason for funny numbers, it seems right to put them out there for others to explain or refute. TGinPA
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