Pressure Trace:PN45 XMR5744 250gr ftx sabotless.
Mar 29, 2011 13:13:43 GMT -5
Post by TGinPA on Mar 29, 2011 13:13:43 GMT -5
Pressure Trace:PN45 XMR5744 250gr ftx sabotless.
For hunting, I am interested in an accurate single powder load which always ignites, is temperature insensitive, with an inexpensive effective bullet, operating in a velocity range for optimal performance out to 200yds. The problem with powders with fast burning rates and sabotted bullets is the sabot which can only take a certain amount of abuse before disrupting, often at velocities which are less than optimal for some purposes. With these powders, sabotless bullets may obturate quickly lowering (at least theoretically) extreme velocity spreads due to seating pressure variance and thereby improving accuracy. With those factors in mind, I am beginning a series of tests of powders with relatively rapid burn rates behind sabotless bullets in a PN45 barrel. To date N110 has been the prototype and I have posted several examples of its usefulness in this regard. But there are other powders with similar burn characteristics (XMR 5744, IMR 4227, IMR SR4759) which may be more available, as good and perhaps even better. Further, as sabotless loads, they are also optimal for warm weather testing because there is no sabot, no need for long waits between shots, and maybe no need for a cooling rod setup. Today, I started this series. Without stretching this powder bullet combination to its limits, I think the test shows pressure/velocity characteristics that may make this combination useful.
Gage and Module Manufacturer = RSI USB model
Trigger Sensitivity = 2, Strain Gage Voltage =4.9 Gage Factor =2.1 PSI Correction Factor: 0
Barrel Temp = 64-66 degrees F. measured at the sensor (IR). Rifle Stand: Caldwell Lead Sled
Altitude: 450 ft Chronograph: Chrony Alpha Model 8 ft from muzzle. (8 fps added to all recorded velocities to correct for distance of chrony from muzzle.)
Barrel Type: PacNor .45 Cal Muzzleloader Barrel OD = 1.06 in Barrel ID = .452
Breech Plug:Savage Std. (screw-in ventliner) ventliner orifice .033 in. Sensor dist fm BP=1.1 in. Bullet Diam.= .458 in. Bullet Type = Hornady 250gr ftx. Bullet weight = 250gr. ,knurled. Resized to .448in. Sabot: None. Wads:Wool lubed over .462x.060in lubed fiber.
Powder: T1= XMR5744 40 gr. T2=XMR5744 45gr. T3=XMR5744 50gr. Primer :Fed 209
Shot fm dirty barrel. This load seemed safe in my barrel under the test conditions but may not be so in other conditions.
For hunting, I am interested in an accurate single powder load which always ignites, is temperature insensitive, with an inexpensive effective bullet, operating in a velocity range for optimal performance out to 200yds. The problem with powders with fast burning rates and sabotted bullets is the sabot which can only take a certain amount of abuse before disrupting, often at velocities which are less than optimal for some purposes. With these powders, sabotless bullets may obturate quickly lowering (at least theoretically) extreme velocity spreads due to seating pressure variance and thereby improving accuracy. With those factors in mind, I am beginning a series of tests of powders with relatively rapid burn rates behind sabotless bullets in a PN45 barrel. To date N110 has been the prototype and I have posted several examples of its usefulness in this regard. But there are other powders with similar burn characteristics (XMR 5744, IMR 4227, IMR SR4759) which may be more available, as good and perhaps even better. Further, as sabotless loads, they are also optimal for warm weather testing because there is no sabot, no need for long waits between shots, and maybe no need for a cooling rod setup. Today, I started this series. Without stretching this powder bullet combination to its limits, I think the test shows pressure/velocity characteristics that may make this combination useful.
Gage and Module Manufacturer = RSI USB model
Trigger Sensitivity = 2, Strain Gage Voltage =4.9 Gage Factor =2.1 PSI Correction Factor: 0
Barrel Temp = 64-66 degrees F. measured at the sensor (IR). Rifle Stand: Caldwell Lead Sled
Altitude: 450 ft Chronograph: Chrony Alpha Model 8 ft from muzzle. (8 fps added to all recorded velocities to correct for distance of chrony from muzzle.)
Barrel Type: PacNor .45 Cal Muzzleloader Barrel OD = 1.06 in Barrel ID = .452
Breech Plug:Savage Std. (screw-in ventliner) ventliner orifice .033 in. Sensor dist fm BP=1.1 in. Bullet Diam.= .458 in. Bullet Type = Hornady 250gr ftx. Bullet weight = 250gr. ,knurled. Resized to .448in. Sabot: None. Wads:Wool lubed over .462x.060in lubed fiber.
Powder: T1= XMR5744 40 gr. T2=XMR5744 45gr. T3=XMR5744 50gr. Primer :Fed 209
Shot fm dirty barrel. This load seemed safe in my barrel under the test conditions but may not be so in other conditions.
