Project SIG P365X, RMR 115gr, MPRJHP, Continued


Aug 14, 2014
It has been a while, but finally I was able to test another group of loads with my P365X using the RMR 115gr MPRJHP bullet. My plan is still the same, find an accurate and reliable load, meeting the magical 1,150fps. This is the velocity RMR tested these bullets for expansion.

I indicated previously that it would be a long term project, but never anticipated that my testing time would dry up for a while. Hopefully now I'll be able to test loads more frequently, and not one load per year.

Following are links to my previous tests using CFE Pistol and AA5:

This time I decided to try W244. There is no +p Hodgdon load data for W244, but the regular 9mm load showed possibly reaching 1,150fps. My test results with the 3.1" P365X showed that my targeted 1,150fps was not reached, loading to the max for Hodgdon data. W244 is probably not the best powder in any case for a defensive round, so I will not proceed with any additional W244 loads to try and meet my specific goals.

Following are the test results:

9mm, P365X, 3.1"Case: FC
COL: 1.075"
RMR, 115gr, MPRJHP, W244, 4.2gr, FED100
Average: 1026
ES: 48
SD: 18.3
Force: 269
PF: 117
Velocities: 1035, 1023, 1017, 1053, 1005
Grouping @ 15yd: 0.73"
Test Date: 09/14/2023
9mm, P365X, 3.1"
Case: FC
COL: 1.075"
RMR, 115gr, MPRJHP, W244, 4.3gr, FED100
Average: 1028
ES: 22
SD: 9.3
Force: 270
PF: 118
Velocities: 1038, 1036, 1022, 1029, 1016
Grouping @ 15yd: 1.27"
Test Date: 09/14/2023
9mm, P365X, 3.1"
Case: FC
COL: 1.075"
RMR, 115gr, MPRJHP, W244, 4.4gr, FED100
Average: 1042
ES: 28
SD: 11
Force: 277
PF: 119
Velocities: 1037, 1054, 1049, 1026, 1045
Grouping @ 15yd: 1.24"
Test Date: 09/14/2023
9mm, P365X, 3.1"
Case: FC
COL: 1.075"
RMR, 115gr, MPRJHP, W244, 4.5gr, FED100
Average: 1069
ES: 14
SD: 5.6
Force: 292
PF: 122
Velocities: 1074, 1062, 1067, 1076, 1068
Grouping @ 15yd: 0.95"
Test Date: 09/14/2023
9mm, P365X, 3.1"
Case: FC
COL: 1.075"
RMR, 115gr, MPRJHP, W244, 4.6gr, FED100
Average: 1067
ES: 13
SD: 5.2
Force: 291
PF: 122
Velocities: 1069, 1064, 1073, 1060, 1070
Grouping @ 15yd: 1.52"
Test Date: 09/14/2023
9mm, P365X, 3.1"
Case: FC
COL: 1.075"
RMR, 115gr, MPRJHP, W244, 4.7gr, FED100
Average: 1103
ES: 19
SD: 8
Force: 311
PF: 126
Velocities: 1104, 1106, 1108, 1108, 1089
Grouping @ 15yd: 1.6"
Test Date: 09/14/2023
My handguns like those RMR Nukes. I use the 124 grainers over HP38/W231. Mine are of medium to med-high charge weight, but I have no 9mm chrony data.
Thanks for the information. The only reason why I am going down the 115gr path is it will be easier to reach 1,150fps out of the 3.1" barrel with a 115gr bullet vs a 124gr bullet.
I played with W244 a little and still have some left.
Normally the vels Hodgdon lists for some of their powders (HP38/CFE-P) for example are close to what I get in my guns.
W244 was quite a bit slower than I expected from listed vels, don't know if maybe I just had a slow lot?
Curious if anyone else has seen this with W244.
(don't mean to hijack the thread but since W244 was mentioned )
This is easily achievable with be86, power pistol, and sillhouette.
Thanks Jake.

My plan was to not really push it for velocity, put do normal testing and see which powder will give me the accuracy. Then the added bonus will be making the 1,150fps with the accurate load. So I am planning to stay within published load boundaries.

BE86 was going to be my next powder, and then followed by Power Pistol. I have not played with Silhouette yet.
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So what is "magical" about 1,150 fps?
For expansion of bullet. From RMR 115 gr MPR/JHP webpage -

We have been wanting to make a really good self defense HP for a while now. In the past our biggest issue with the MPR (Multi Purpose Round) was that it required 1150-1200 fps to reliably expand. This was doable through full size firearms, but left the short barrel conceal carry guns without much hope of success. So, we went full out and redesigned our bullet. We pre-cut the lead core so that it will easily open upon impact. Our NUKE is unique in that we gave it three internal petals and six external jacket cuts. The result in ballistics gel is pretty impressive. At 1100 FPS we’re getting about 14″ of penetration with a diameter of about .630″ in total expansion. At 1000 fps we are getting 16-17″ of penetration with a diameter of about .590″ in total expansion.​
So If I have a load for the 124 gr nuke that is running a consistent 1,085 fps...........perps and thugs won't be happy on the receiving end?

In other need to keep pushing it up if it's an easy shooting load?
So what is "magical" about 1,150 fps?
When I started this testing, the velocity mentioned was still 1,150fps for expansion. My plan with these load development is to find an accurate load, then see which accurate load also reaches the 1,150fps velocity. It is easy to just aim for velocity, but the combination of velocity and accuracy is what I am after.
Thanks for providing the information. I can probably change the goal to 1000fps, but I will just present that data, and everybody can take/use from it what they want.