The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Thread Tools Search this Thread
Old February 20, 2019, 09:55 AM   #1
Join Date: April 14, 2013
Location: Akron, Ohio
Posts: 22
RMR 115 MPR (JHP) Load Development

For those that don't know, Rocky Mountain Reloading has released new in-house 115 and 124 grain JHP 9mm bullets. The price is very attractive, and since I have always been happy with everything else I've gotten from RMR, I decided to try out these new bullets. I went with the 115 for 9mm Luger. With this being a new bullet, there is not much information out there for loading it, so I thought I would post load development and results here for anyone interested in trying these out.

So far, the only powder I have tried out with them is CFE Pistol, but I will update this as I play around with more powders if anyone is interested.

These loads were all developed in CBC (Magtech) once-fired brass, with Hodgdon CFE Pistol and CCI 500 Primers.

The first thing that I learned about these bullets is that the need to be loaded somewhat short. My first rounds were loaded at 1.125'' with 5.3, 5.5 and 5.7 grains of CFE Pistol. I test fired them through my Glock 17, G4. I had one round where the slide didn't go into battery, but with a light touch on the back of the slide, it other problems with the Glock and these rounds.

Chrono Data:

5.3 CFE Pistol 1.125''

1.) 1096
2.) 1089
3.) 1095
4.) 1091
5.) 1090

5.5 CFE Pistol 1.125''

1.) 1079
2.) 1139
3.) 1124
4.) 1128
5.) 1160

5.7 CFE Pistol 1.125''

1.) 1167
2.) 1170
3.) 1150
4.) 1161
5.) 1186

Since I had the slight hiccup with the Glock 17, I decided I should try some of these in the CZ 75B....yes, I should have used this gun's barrel for a plunk test, since these are know for there short leads but I was feeling lazy....and that's is where the saying 'why is there never time to do it right, but always time to do it twice' comes from.

The first round chambered and fired....the second round required a lot of pulling on the slide to get the cartridge that would not fit into the chamber back out...back to the bench.

This time, I used the CZs barrel as a cartridge gauge and ended up with a COAL of 1.065''. A big difference, but they chambered perfectly in the CZ. Because of the large reduction in OAL, I backed way off on the powder and started over. Seated to this depth, there is .210'' of bullet seated into the case, which is perfectly fine for a 9mm Luger. I consider anything up to .300'' of bearing surface in the case safe for 9mm, but I work up accordingly, just as I did here.

Hodgdon lists a starting charge of 5.3 grains of CFE Pistol for a 115JHP, but this is seated much longer, and since I did not have the same bullet for comparison, backed off .5 grs. and started at 4.8 grains for the new shorter rounds, and also loaded a few 5.0 grains. These were fired from the CZ 75B.

Chrono Data:

4.8 CFE Pistol 1.065''

1.) 1086
2.) 1062
3.) 1073
4.) 1049
5.) 1070

5.0 CFE Pistol 1.065''

1.) 1093
2.) 1128
3.) 1144
4.) 1137
5.) 1138

Both of these loads cycled the CZ just fine, and made a nice pile of brass close to where I was. The 5.0 grain load was my favorite, and the most accurate of the bunch. Jake at RMR says these need to be loaded to 1100 fps of faster for reliable expansion, and I would say the 5.0 load accomplishes this with good accuracy as far as I'm concerned, so I don't really see the need to try for more velocity, although I may mess with some different powders. I'll add more info as I get more time to mess with this bullet.

All in all, this is a great bullet, and I hope this gives some people enough info to give it a try...Maybe I'll pick up some of the 124s for 9mm and .357 Sig

Also posed on thehighroad
Blue Dot is the best 10mm Powder.

Last edited by KASarich; February 20, 2019 at 10:07 AM.
KASarich is offline  
Old February 22, 2019, 07:12 PM   #2
Senior Member
Join Date: March 21, 2013
Location: Taxifornia
Posts: 4,924
KASarich, Good load work up. And good personal experience for you. Now that you've got the correct OAL, you can focus on spending more time on the propellant charge levels. Might I recommend going with 10 round samples, now that you have things narrowed down a bit.

Your velocities look pretty consistent. Might I also suggest that once you get to testing 10-round samples, you focus on your Standard Deviation (probably not a valuable number with 5-round samples). When your SD's are low, you know you've got a well crafted, good, consistent burner. And - I've never shot low SD pistol ammo that wasn't accurate.

I like to see load work up range reports. Thanks.

Gun control laws benefit only criminals and politicians - but then, I repeat myself.
Life Member, National Rifle Association

Last edited by Nick_C_S; February 22, 2019 at 07:35 PM. Reason: Typo
Nick_C_S is offline  
Old March 1, 2019, 01:15 PM   #3
Join Date: April 14, 2013
Location: Akron, Ohio
Posts: 22
So, I've finally had a little time to put a few more of these rounds together and fire them over the chrono. I made two ten-round samples of both 5.0 gr. and 5.1 gr. CFE Pistol. The results are as follows:

5.0 CFE Pistol Avg. Vel.) 1123 ES:90fps SD:23pfs

1.) 1064
2.) 1119
3.) 1121
4.) 1135
5.) 1154
6.) 1128
7.) 1112
8.) 1130
9.) 1134

5.1 CFE Pistol 1.065'' Avg. Vel.) 1154fps ES:108fps SD:30fps

1.) 1083
2.) 1156
3.) 1189
4.) 1159
5.) 1146
6.) 1154
7.) 1170
8.) 1128
9.) 1191

For the 31fps I gain with the additional powder, I give up in SD and ES, although both rounds were accurate for me, but I'm not doing any scientific accuracy chrono is 6 feet from me, and my target is about 12 feet beyond that. I'm shooting from a standing position. After the 20 rounds, the center of the target was cleared out nicely...perfect for the plinking / general purpose round I am loading.

I would like to try out some different powders with this bullet, maybe I can get those SD numbers down. Any recommendations?
Blue Dot is the best 10mm Powder.
KASarich is offline  

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 08:25 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent:
Contact Us
Page generated in 0.07413 seconds with 8 queries