Pressure Traces:PN45 5744/RL7 200xtp
Sept 23, 2011 15:45:19 GMT -5
Post by TGinPA on Sept 23, 2011 15:45:19 GMT -5
Pressure Traces:PN45 5744/RL7 200xtp
On 9/19, I posted a trace expected to perform well in cold weather, using RL7 as a primary with SR4759 as booster. Several pointed out that pressures attained with that load might cause sabot disruption under some conditions and suggested that I tone it back a bit, decreasing the booster and increasing the primary. The traces below show two attempts to lower pressure while maintaining or even increasing velocity by altering the booster-primary ratio, increasing the primary while decreasing the booster. In both, using the tracings as a guide, this was easily accomplished.
Yesterday, I posted traces using SR4759 as the booster with RL7 as the primary. Comparison with today’s results shows the similarity between identical weight charges of XMP5744 and SR4759(metal can) as boosters for almost the same amount of primary. The major difference between the two was shown by the relative quickness of the rise in curve upslope of XMP5744 (130 v. 150) in comparison with the same charge weight of SR4759(metal can) posted on 9/22. Because quickness of upslope rise may affect sabot stability, these trace comparisons might suggest that at a given weight of booster (XMP5744 or SR4759) with comparable loads of primary, SR4759 as traced on 9/22 might theoretically be the better choice in some circumstances if sabot disruption is the major concern when using a duplex load designed to give maximum velocity.
TG
Gage and Module Manufacturer = RSI PTII Bluetooth model.
Trigger Sensitivity = 7 Strain Gage Voltage =4.992 Gage Factor =2.11 PSI Correction Factor: 4kpsi.(calibrated to my standard load) Rifle Stand: Caldwell Lead Sled. Altitude: 450 ft Chronograph: Chrony Alpha Model 8 ft from muzzle. (13 fps. added to all recorded velocities to correct for distance of chrony from muzzle.)
Barrel Type: PacNor .45 Cal Muzzleloader Barrel OD = 1.06in. Barrel ID = .452in.
Breech Plug:Savage Std. (screw-in ventliner) ventliner orifice .032 in. Sensor dist fm BP=1.125in. Bullet Diam.= .400in. Type = Hornady XTP Bullet weight = 200gr. ,unknurled. Sabot:Harvester smooth blue Sabot wt.= 9gr. Wads: None Primer: Fed 209A
Powder:Panel 1:XMP5744/Reloder 7 11/56gr. Panel 2:XMP5744/Reloder 7 11/58gr
Shot fm. dirty barrel. These loads seemed safe in my barrel under the test conditions but may not be so in other conditions.
On 9/19, I posted a trace expected to perform well in cold weather, using RL7 as a primary with SR4759 as booster. Several pointed out that pressures attained with that load might cause sabot disruption under some conditions and suggested that I tone it back a bit, decreasing the booster and increasing the primary. The traces below show two attempts to lower pressure while maintaining or even increasing velocity by altering the booster-primary ratio, increasing the primary while decreasing the booster. In both, using the tracings as a guide, this was easily accomplished.
Yesterday, I posted traces using SR4759 as the booster with RL7 as the primary. Comparison with today’s results shows the similarity between identical weight charges of XMP5744 and SR4759(metal can) as boosters for almost the same amount of primary. The major difference between the two was shown by the relative quickness of the rise in curve upslope of XMP5744 (130 v. 150) in comparison with the same charge weight of SR4759(metal can) posted on 9/22. Because quickness of upslope rise may affect sabot stability, these trace comparisons might suggest that at a given weight of booster (XMP5744 or SR4759) with comparable loads of primary, SR4759 as traced on 9/22 might theoretically be the better choice in some circumstances if sabot disruption is the major concern when using a duplex load designed to give maximum velocity.
TG
Gage and Module Manufacturer = RSI PTII Bluetooth model.
Trigger Sensitivity = 7 Strain Gage Voltage =4.992 Gage Factor =2.11 PSI Correction Factor: 4kpsi.(calibrated to my standard load) Rifle Stand: Caldwell Lead Sled. Altitude: 450 ft Chronograph: Chrony Alpha Model 8 ft from muzzle. (13 fps. added to all recorded velocities to correct for distance of chrony from muzzle.)
Barrel Type: PacNor .45 Cal Muzzleloader Barrel OD = 1.06in. Barrel ID = .452in.
Breech Plug:Savage Std. (screw-in ventliner) ventliner orifice .032 in. Sensor dist fm BP=1.125in. Bullet Diam.= .400in. Type = Hornady XTP Bullet weight = 200gr. ,unknurled. Sabot:Harvester smooth blue Sabot wt.= 9gr. Wads: None Primer: Fed 209A
Powder:Panel 1:XMP5744/Reloder 7 11/56gr. Panel 2:XMP5744/Reloder 7 11/58gr
Shot fm. dirty barrel. These loads seemed safe in my barrel under the test conditions but may not be so in other conditions.