More Load Data for RMR 124 JHP - TiteGroup

[Doublehelix]

There are a few threads already running with some data on these bullets, but some are specific to BE-86, etc. and I did not want to hijack those threads.

As I mentioned in one of those threads, I have been loading the new-style RMR JHP (Jake calls them "Multi-Purpose Rounds" or MPR) at a COAL of 1.125". I know a lot of folks are incredulous that these can chamber and fire, but they do work fine in my SIG P226 Legion SAO. The problem for me is that they WILL NOT chamber in any of my other guns, so I decided to work up a new TiteGroup load with a shorter COAL of 1.06".

Plunk tests showed that these shorter cartridges chamber fine in the rest of my guns, and I am happy with this compromise.

My previous load was 4.1 gr of TiteGroup at 1.125". I am aiming for slightly above Minor Power Factor (125), so slightly over 1,000 fps, and then a bit more as a safety buffer.

I figured with the shorter COAL, I would need to go a bit lower than the 4.1 gr I was loading previously, so I made some test loads at 3.9 gr, 4.0 gr, and 4.1 gr., all at 1.06", and then I compared the chronograph data with the longer loads at 4.1 gr.

Here are the results:

Bullet Type: RMR JHP
Bullet Weight: 124
Powder: TG
Weight: 3.9
COAL: 1.06
Primer: CCI 500
Case: Mixed

Stats - Average 1028.60 fps
Stats - Highest 1090.00 fps
Stats - Lowest 994.00 fps
Stats - Ext. Spread 96.00 fps
Stats - Std. Dev 28.49 fps
Avg Power Factor 126.36

---

Bullet Type: RMR JHP
Bullet Weight: 124
Powder: TG
Weight: 4.0
COAL: 1.06
Primer: CCI 500
Case: Mixed

Stats - Average 1036.60 fps
Stats - Highest 1054.00 fps
Stats - Lowest 1014.00 fps
Stats - Ext. Spread 40.00 fps
Stats - Std. Dev 13.08 fps
Avg Power Factor 127.05

---

Bullet Type: RMR JHP
Bullet Weight: 124
Powder: TG
Weight: 4.1
COAL: 1.06
Primer: CCI 500
Case: Mixed

Stats - Average 1054.00 fps
Stats - Highest 1072.00 fps
Stats - Lowest 1026.00 fps
Stats - Ext. Spread 46.00 fps
Stats - Std. Dev 15.72 fps
Avg Power Factor 129.58

---

Bullet Type: RMR JHP
Bullet Weight: 124
Powder: TG
Weight: 4.1
COAL: 1.125
Primer: CCI 500
Case: Mixed

Stats - Average 1049.43 fps
Stats - Highest 1089.00 fps
Stats - Lowest 1002.00 fps
Stats - Ext. Spread 87.00 fps
Stats - Std. Dev 32.87 fps
Avg Power Factor 129.21


A couple of these sets have fairly high ES and SD numbers, but that seems to be pretty common with TiteGroup. I am measuring the powder with my Dillon Powder Measure, and then verifying every load on my scale. I did have some slight COAL variation as I dialed in the seating die a bit more as I went along. This was certainly the case with the 3.9 loads at 1.06".

What surprised me about this data was the small difference in avg velocity between the same loads at 1.06" vs. 1.125"... only 4.57 fps. I guess the 6.5 thousands did not change the velocity that much at all, certainly less than I expected. In fact, I am probably going to just keep loading 4.1 gr of TiteGroup, even with the shorter COAL since these fit right into my PF range, and were the most accurate of the three loads with the shorter COAL.

AS ALWAYS: Use these loads at your own risk, and ALWAYS start low and work up, checking each load as you go for over-pressure signs and high velocities. You assume all risk, and you should always consult a reliable loading manual for more accurate and safely tested loads.

 

[Dill]

your data almost exactly matches mine. just finished another 1000 rounds on the Lee 1000, 124g FMJ's and 4.1gr of TG. It's kind of cool to see this to be honest.

 

[Doublehelix]

your data almost exactly matches mine. just finished another 1000 rounds on the Lee 1000, 124g FMJ's and 4.1gr of TG. It's kind of cool to see this to be honest.

It seems to be pretty accurate as well. Are you loading to 1.06" as well?

 

[Sunray]

You do not need bullet specific data. Any 124 or125 grain jacketed data will do.
And 'power factors' are a shooting game invention.

 

[Doublehelix]

You do not need bullet specific data. Any 124 or125 grain jacketed data will do.

Not sure what you are saying here. Sorry. Different bullets have different geometries and construction and have different seating depths, even for the same weight. Maybe you can elaborate more on what you mean here?

And 'power factors' are a shooting game invention.

Yes. I am not sure what your point is here.

I just mentioned that I am aiming for a specific PF because I *do* participate in shooting games, and want the softest loads I can get that meet PF. That does not mean that these loads work for everyone, these are for *me* to meet Minor PF.

 

[Dudedog]

Yes PF is a shooting game invention, but if you are playing the game it is important.

 

[Dill]

right around 1.10" give or take a little as I'm using a Lee 1000 and pulled FMJ's. I just used my last 1000 pulls, will probably try the 124 RMR's next once I shoot these up.

It seems to be pretty accurate as well. Are you loading to 1.06" as well?

 

[ray15]

You do not need bullet specific data. Any 124 or125 grain jacketed data will do.

Yes, you can use any load data, but you also don't know what kind of chamber pressures will result in your gun with your bullets' hardness, bearing surface area, diameter, base design and the seating depth. As such this constitutes dangerously poor advice.

Let me give you an example. This is the only 115gr. jacketed data available from Hodgden for my powder of choice, CFE Pistol:



I referenced this data when loading the RMR-produced 115gr. FMJs, which do measure .355". But low and behold, they produce ~1200fps with a 5.4gr charge at an OAL of 1.13", indicating pressures nearing max. If I were to use the listed max of 5.9gr, pressures would be far in excess of SAAMI max for 9mm luger, and might exceed +P levels as well. Sure I could use their data verbatim - if I was stupid. And likely this is not the furthest deviation from the available load data one might encounter.

 

[LiveLife]

ray15, you may be getting extra velocity from RMR sizing their 115 gr FMJ slightly larger at .3555". Since many factory barrels run groove diameter around .356"+, slightly larger sized .3555" bullets can produce greater accuracy than .355" sized bullets from tighter fit with barrel and less gas leakage.

FYI, Hornady 125 gr HAP made for match shooting and bullet many consider to be reference bullet for accuracy is sized .356" and clearly marked on box as .356" - https://www.thehighroad.org/index.p...re-sized-the-same.818806/page-2#post-10567453

This is from MidwayUSA bulk packaged box

Also, Zero 115 gr FMJ, bullet I believe Atlanta Arms used/currently use to produce their Elite Match AMU ammunition (which must meet less than 1.5" 10 shot groups at 50 yard requirement) is also sized larger at .356" - https://atlantaarms.com/products/9mm-115gr-fmj-match-amu.html

Of course, using larger .356" sized bullets will require use of even less powder to produce same velocities.

 

[ray15]

The point was not why, but that it happens. You can't just use any load data, and this is an important safety point I would prefer not to dilute. I agree the bullets are .3555 (a slight imprecision to my original post), but that's not all that's at work here.

What I related is actually the best-case scenario for this combination - as at 1.13" OAL these round would not chamber in a gun with less leade. If you care to make them chamber in anything, you are at 1.100", and hit max pressures below the starting charge listed by Hodgden - at 5.1-5.2 grains. Loading up 5.9 grains would not be safe.

 

[Doublehelix]

The point was not why, but that it happens. You can't just use any load data, and this is an important safety point I would prefer not to dilute. I agree the bullets are .3555 (a slight imprecision to my original post), but that's not all that's at work here.

^^^THIS^^^

We have to be careful with blanket statements as Ray points out as they can lead to dangerous generalizations.

 

[vaalpens]

I don't want to be critical or anything, but you are trying to make minor, your averages are just above minor, but your ES numbers are 40fps and higher. It seems to me that you will need to increase your velocity with those ES numbers to make minor safely. Out of all my 9mm loads that I have chrono'd, I just have a handful with ES numbers of 40fps and higher.

With the RMR JHP bullets which are very consistent in their diameter, I would think you should see better ES numbers. This is one of my loads (sorry no Titegroup) that I chrono'd:

9mm, SIG SP2022, 3.9"
COL: 1.075"
RMR, 124gr, JHP, BE86, 5.6gr, SBPRSP
Average: 1109
ES: 8
SD: 3.6
Force: 339
PF: 137
Velocities: 1110, 1106, 1112, 1106, 1114

 

[LiveLife]

ES: 8
SD: 3.6

That's pretty impressive.

 

[Doublehelix]

I don't want to be critical or anything, but you are trying to make minor, your averages are just above minor, but your ES numbers are 40fps and higher. It seems to me that you will need to increase your velocity with those ES numbers to make minor safely. Out of all my 9mm loads that I have chrono'd, I just have a handful with ES numbers of 40fps and higher.

Yeah, those are great numbers you got, no doubt! I appreciate your feedback, and I seem to get high numbers a lot with Titegroup, much higher than with any other powder. Does anyone else see that? The numbers I got look horrible, especially compared to yours...

I am not really sure how to get tighter spreads and lower SD numbers with TG, I am pulling my hair out. I am dropping from a Dillon powder measure, but with those loads from above that I worked up for testing, I was checking *every* load on my RCBS Chargemaster. There is some COAL variation for sure, especially on the first set (3.9 gr) as I fine tuned the seating die a bit. But the 4.0 and 4.1 loads were pretty consistent from a COAL standpoint. I am using nice dies as well (Redding Competition with a Lee FCD).

Also as mentioned, my numbers look much better with other powders. Here is an example with 5.6 BE-86 and these same bullets (the same load you posted, but at a longer COAL):

Bullet Type: RMR FMJ
Powder: BE-86
Weight: 5.6
COAL: 1.125
Primer: CCI 500
Case: Federal

Stats - Average 1213.91 fps
Stats - Highest 1229.57 fps
Stats - Lowest 1211.81 fps
Stats - Ext. Spread 17.76 fps
Stats - Std. Dev 9.15 fps

Avg Power Factor 146.63

The numbers aren't as good as yours, but they are better than I get with Titegroup... consistently.

I'd love to hear some suggestions on this and others experiences with TG.

 

[Jesse Heywood]

Despite Hodgdon's claims, TiteGrope is position sensitive. Walkalong has posted his results numerous times.
www.thehighroad.org/index.php?threads/position-sensitive.436766

 

[Dudedog]

Some people really like Titegroup. I only burned a lb but for me it just didn't work as well as a lot of other powders I had tried.
At that burn speed I had better results with Bullseye and Promo.

 

[LiveLife]

Despite Hodgdon's claims, TiteGrope is position sensitive. Walkalong has posted his results numerous times.
www.thehighroad.org/index.php?threads/position-sensitive.436766

But for semi-autos, when the round is chambered and powder charge slams forward, we are always shooting "powder forward" unless we are pointing up.

 

[vaalpens]

That's pretty impressive.

Thanks. I have a few with those numbers, but since the sample was only 5, the next 5 will definitely be different.

 

[Jesse Heywood]

But for semi-autos, when the round is chambered and powder charge slams forward, we are always shooting "powder forward" unless we are pointing up.

Agreed. But an very consistent grip is needed. Far better than I can do.

It could also a good reason to exclude the first shot from the results. Perhaps someone would be willing to test and report.

 

[LiveLife]

It could also a good reason to exclude the first shot from the results. Perhaps someone would be willing to test and report.

I have, along with shooting a magazine full of rounds to "foul" the barrel, shooting powder forward vs back using OAL from 1.110" to 1.160".

What I found is that unless I am near max or at max load data, using shorter OAL (which increases neck tension) produces smaller shot groups than longer OAL. I thought this was mainly from greater neck tension producing more consistent initial chamber pressure build but fuller case fill with powder covering the primer when primer ignites could also explain the smaller shot groups.

With my newest Lone Wolf barrel with no leade, I started doing load development with RMR 115 gr FMJ at shorter 1.110"-1.115" OAL which almost ensures my rounds are near/full case fill loads.