Seater plug for RMR's 9mm 124 Gr. Truncated Cone Flat Point

[Walkalong]

Do I detect the absence of any taper crimp in the photos.

You are seeing proper taper "crimps'.

 

[YBOT]

You are seeing proper taper "crimps'.

I have noticed in my recent reading of late mention of this. I’ll be making a few dummy rounds to start for a plunk test. BTW, thanks Walkalong for the link to plunking. The learning is a good part of the fun.

Update: As for the taper I’ll try to approach the #28 post of bds. Looks like a precise touch to remove the bell.

 

[LiveLife]

Thanks very much bds.

Do I detect the absence of any taper crimp in the photos.

You are very welcome.

As to amount of taper crimp, since case wall thickness average .011", I usually add .022" to the diameter of the bullet. So for .355" sized bullet, .377" taper crimp and for .356" sized bullet, .378" taper crimp. This ensures I return the flare back flat on the bullet.

Here's RMR 124 gr FMJ (.3555" diameter) loaded to 1.120" with .378" taper crimp. I am using Lee combo seat and taper crimp die and it applies very gradual taper crimp that runs the length of the case neck towards case mouth.

 

[1MoreFord]

My dies are RCBS and I've had about equal success with truncated cone bullets using both seater plugs. I always felt they were more relevant to Keith style vrs round nose.

 

[Dudedog]

These are the 124 MPR JHP not the FN but maybe helpful

5" 9mm 1911 S+B SP Mixed range brass
String: 1
Date: 10/29/2017
Time: 9:37:06 AM
Grains: 124
Hi Vel: 1012
Low Vel: 981
Ave Vel: 998
Ext Spread: 31
Std Dev: 11
RMR 124 MPR JHP 4.0 HP38 1.055 OAL 5inch 1911
Velocity Power Factor Ft/Lbs
1002 124.248 276.413
995 123.38 272.565
981 121.644 264.948
1012 125.488 281.958
1004 124.496 277.518
Does not make PF almost

Longer OAL
String: 2
Date: 7/23/2017
Time: 10:44:23 AM
Grains: 124
Hi Vel: 1046
Low Vel: 1003
Ave Vel: 1026
Ext Spread: 43
Std Dev: 16
RMR 124 MPR-HP 4.5 HP38 1.08 OAL
Velocity Power Factor Ft/Lbs
1003 124.372 276.965
1036 128.464 295.49
1022 126.728 287.558
1025 127.1 289.248
1046 129.704 301.222

 

[YBOT]

Thanks to you all. Itching to get to the loading bench now. Rain here so a good time to hunker down in the shop.
I’ll sure keep you all posted on my progress. Got to get it in gear while the range I use is still open because of the ugly low temps and snow we’ll be getting.....lol

Gents, I’m love’in the details you all are providing.

 

[thomas15]

I’ll sure keep you all posted on my progress.

Hog Heaven dude, Hog Heaven!

 

[YBOT]

What would you suggest to clean the mfg. oils from a new powder through expanding die that I have on the way please?

 

[longdayjake]

Don't use brake cleaner. That will eat the paint away. Are you using a Dillon powder through expander? I personally just took mine apart and wiped it out.

 

[YBOT]

Are you using a Dillon powder through expander?

Hi Jake, it's a Lee. Just ordered some of your 9mm 124 Gr. RMR Jacketed Hollow Point (Multi Purpose Round) Bullets today to give a try.

 

[Blue68f100]

What would you suggest to clean the mfg. oils from a new powder through expanding die that I have on the way please?

Hornady OneShot Gun cleaning solvent works good. Leaves a dry film behind to lubricate and help prevent rusting. Paste wax is about the best to comve bare metal to keep if from rusting.

 

[drband]

Jake said wipe it out and I agree!

Don't use brake cleaner. That will eat the paint away. Are you using a Dillon powder through expander? I personally just took mine apart and wiped it out.

The graphite in the powder will take care of any small amounts remaining. Just be sure to check your powder wt. regularly till you’ve used it for a bit.

 

[Dudedog]

I have more chrono data for some loads with different powders for the MPRs in 9mm, if your interested PM me.

 

[YBOT]

Setup the Lyman dies to make up a couple of dummy loads with the RMR 9mm 124gr FMJ FN bullets. Checked these with a Lyman 9mm gauge and did my first plunk test in the barrel that I plan on using with the live rounds. I'm not sure about the amount of taper crimp that I applied and measured at the mouth of the case and being 0.0005". I'm wondering if this should be more like 0.001" to 0.002" ?

Not a good angle on the plunk test photo but I thought it looked good.

 

[LiveLife]

If the finished rounds pass the gauge and drop freely in the chamber and spin without hitting the rifling, you should be fine.

SAAMI max for 9mm case mouth is .380" but for my KKM and Lone Wolf barrels, I prefer to taper crimp to .378" max to allow my rounds to feed/chamber reliably even when barrels are dirty.

 

[drband]

Now you’ll just have to go shoot a few!

Just for information: I have a P938 that will not cycle RMR RNFP bullets unless seated significantly deeper than the 124gr FMJ or 124RN plated bullets. Something about how the ogive shape affects clambering. They measure and plunk just fine, but have to be seated shorter than 1.10” to reliably chamber.

Hopefully the TCFP will not have that problem.

Good luck with your testing!

 

[Walkalong]

Looks real good. Time to load a few and try them.

 

[YBOT]

If the finished rounds pass the gauge and drop freely in the chamber and spin without hitting the rifling, you should be fine.

I did forget to try the spin test when I plunked but I’ll correct that his morning. Thanks for your guidance.

Now you’ll just have to go shoot a few!

Good luck with your testing!

Thanks. Yes, load up maybe five rounds only for the initial test. Does “TCFP” stand for “truncated flat point”?

 

[LiveLife]

I have a P938 that will not cycle RMR RNFP bullets unless seated significantly deeper than the 124gr FMJ or 124RN plated bullets. Something about how the ogive shape affects clambering. They measure and plunk just fine, but have to be seated shorter than 1.10” to reliably chamber.

Yes, imagine RNFP as RN with tip taken off and you will need to seat it much shorter to match the seated profile of RN.

RMR MPR has similar nose profile as RNFP and I need to load it shorter to clear the rifling. If you compare the RN loaded to 1.130" to MPR loaded to 1.050", MPR looks like RN with tip of nose taken off.

 

[drband]

I did forget to try the spin test when I plunked but I’ll correct that his morning. Thanks for your guidance.



Thanks. Yes, load up maybe five rounds only for the initial test. Does “TCFP” stand for “truncated flat point”?

Yes. Truncated Cone Flat Point

 

[YBOT]

Yes. Truncated Cone Flat Point

Thanks. I'll write "Cone" on the board fifty times and lock it in...……….. LOL Oh, this wee mind of mine.

I do think I'll tighten that taper crimp a tad more from what I have it set at now. Like bds thinking there.

I did recheck the plunk test this morning and the spin check was smooth with no grab of the rifling that I could detect. Think the new photo is more readable.

 

[YBOT]

Yesterday made it to the range to test my 1st reload of the RMR 124gr FMJ TCFP bullets. I loaded six rounds and set up my target 27 feet or 8.39 meters from the bench I was using. Why did I pick that distance; there was a flat spot on the ground where I could set up my box to attach my target. you will quickly notice that three of the rounds may look like flyers but I think that was just operator malfunction or firing over and under then for effect..... LOL. The pistol functioned good with feed/chambering. The recoil seemed to be on the mild side. Ejects landed on top of the shooting bench. No issues of any kind. Now I feel confidant enough to load more rounds before the next trip and I'll start increasing the propellent charge by a tenth of a grain as I look for a reasonable accuracy recipe. That little G43 with that 3.39" barrel surprises me. For a CCW piece I guess the distance I chose for testing was in the ball park.

Think I'm going to enjoy these bullets.

Particulars;
Propellent & charge: W231 4.0gr
Primers: CCI 500 Small Pistol
OAL: 1.080 inches



I'll also mention that this was a test of my pound of W231 I purchased in 1995 and has been stored in the powder locker. Seems to have no issues.
​

​

 

[Ole Joe Clark]

We have been shooting a lot of RMR 9 mm bullets over the last couple of years. Waiting on an order now.

 

[YBOT]

We have been shooting a lot of RMR 9 mm bullets over the last couple of years. Waiting on an order now.

I'm waiting on another RMR 9mm order also. The 9mm has really caught my interest. Has me thinking about adding a full size 9 x 19 to the inventory.

 

[YBOT]

My order arrive from RMR yesterday. Love these folks for their service, quality products and to top it off they make it fun! Now, to get to the bench and put together loads using the RMR 124 gr JHP MPR bullet addition to my RMR inventory.