PN45 XMP 5744 35-45gr 200xtp

[TGinPA]

PN45 XMP 5744 35-45gr 200SST
A pressure trace test of this load did not go as planned. After completing the test I managed to accidentally erase the results before I could make a hard copy of the traces. Using the pressure trace setup I have describe in many other posts, I tested 4 shots:
1) 35gr 200sst v= 1991, Peak P~27k psi, rise=60
2) 40gr 200sst v= 2144, Peak P~ 29.5k psi, rise=60
3) 45gr 200sst v=1596, Peak p~ 31k psi, rise=60
4) 45gr 200sst v=1996, Peak p~ 31k psi, rise=60
All shot with Harvester Blue sabot from dirty barrel Under the bullet, two wads were used: .060 x .462in fiber,under a lubed wool wad.
Of interest was a steep pressure rise of all initial traces. Because of that, despite relatively low velocities and peak pressures, IMO, sabot disruption was present for the last two shots. This was also manifested by falling velocities at increased powder volume. No secondary peaks were seen. From this test I believe that for XMP 5744 as a single powder behind a 200gr sabotted bullet, might make a good reduced load, giving velocities approaching 2100fps using 40gr or less with very light recoil and certain ignition while maintaining sabot integrity.
TG

[Savage Shooter]

5744 at 40gr with 200sst would make excellent reduced load for the recoil sensitive shooters around 2100fps.

It would make and excellent 150yd load.

2" high at 100yds makes it zero at 150 and minus 6" at 200.

This would make 900ft/lbs energy still at 200, would have no ignition problems, low ES and should be accurate. Not to mention 10.6 ft/lbs recoil.

[TGinPA]

PN45 XMR 5744 36-40gr 200xtp
When I tested 5744 on 3/28, I lost the pressure trace before I could download it. Today, I repeated some of the load tested on 3/28 with several changes. Conditions and equipment were unchanged from yesterday with exceptions noted below. Today, because I had good evidence that sabot disruption occurred at powder loads above 40gr., I tested only two powder loads below that and recorded the traces shown below. Two warnings are in order. First, for these loads the pressure sensor is .1 in front of the powder charge. Theoretically, this may lower recorded pressures. By how much, I do not know. Second, today, I did not place wads over the powder charge. Past PT tests have shown that wads under the bullet may raise pressures. This may account for the higher pressures seen on 3/28 with similar loads. Comments made on 3/28 test remain unchanged.
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 = 62-64 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 .032 in. Sensor dist fm BP=1.1 in. Bullet Diam.= .458 in. Bullet Type = Hornady 10 mm 200xtp. Bullet weight = 200gr. ,unknurled. Sabot: Harvester Smooth Blue
Powder: Traces 3 and 4: XMR 5744 40gr. Traces 1 and 2:XMR 5744 36gr. 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.

[deadon]

Thanks TG. I wonder why no second peak? This is the way they are supposed to look, correct? Rusty

[Jon]

Tg you may be on to something the lack of a secondary peek is interesting actually that is a good trace now if it can be recreated pressures that would be great. You have to understand since I'm very limited so I look for speed and accurate. Keep up the great work. If there is anything I can contribute let me know? I'm more than willing to help with components etc.
Jon

[GMB54-120]

I would love to see how well these loads work in terms of accuracy. They sure look promising and very economical/pleasant to shoot. A Nosler and XTP 200gr side by side shootout might even show its full potential.

[Savage Shooter]

Mar 29, 2011 11:53:41 GMT -5 deadon said:

Thanks TG. I wonder why no second peak? This is the way they are supposed to look, correct? Rusty

Because the bullet is not "out running" the powder burn....

[Savage Shooter]

5744 can be shot to about 43grs easily according to this PT info.

It is making about 687.5psi/gr and about 54fps/gr.

To reach 30K (30000 divided by 687) would take about 43 - 43.5grs.


43gr times 54.3fps = speed of 2325 to 2350fps with 200gr bullet in a very easy (probably very accurate too) shooting setup @ 30K peak pressure!!

Remember that sabot disruption is not just a product of peak pressure but also a product of time (longer time to peak pressure the sabot can hold more pressure reliably). IMO 43.5gr of 5744 would be about all the sabot can take under any conditions.......due time of rise.