RMR Jacketed 9mm 124gr Choices

[Doublehelix]

When we go to the RMR site under 9mm 124gr bullet, there are several choices for jacketed bullets:

• 9mm Jacketed MPR (JHP)
• 9mm FMJ (Round Nose)
• 9mm FMJ (Flat Nose) *Match Winner*

I started with the standard RN jacketed, and those worked fine, but based on the great reviews around here on the JHP ("Multi-Purpose Rounds), I decided to give those a try.

I found a great load for my SIG P226 using 4.1gr of Titegroup at a COAL of 1.125". These are coming in at about 1072 fps with a Power Factor of about 130.

Today, I took my family to the range, and we tried shooting these cartridges in my HK VP9 and my small SIG P938, and got tons of jams and failure to feeds. Dang. I never bothered to plunk test these in any of my other guns. They feed fine in the P226. I will have to work up a new load with a shorter COAL (after some plunk testing to see if this is indeed the problem).

With the RMR FMJ RN bullets, I was loading at 1.150" (corrected value, had a typo originally) and they plunked and fed well in all of my guns, and I get why this is with different ogive angles, etc. I have no problem with understanding that part.

But, as I look back, I am not sure why I switched other than what others were saying. The RN FMJs worked fine, and are after all, less money than the JHPs.

I do not make my own SD loads, and I don't want to open up a debate on handloads for SD vs. factory loads. I am using Federal HST, and have ZERO plans to switch.

So after all of that...

Why would one choose one of these 3 bullet types over another? I have no need for expansion since as I mentioned, I use factory self defense loads. Benefits/advantages of one type vs. another?

I just ordered another 3,000 of the JHPs, and I have another 2,000 of the FMJ RNs.

Thanks,

 

[noylj]

In terms of accuracy, I find the rating as follows:
1) L-HBWC
2) JHP or L-SWC
3) FMJ-FN or L-CFP
4) FMJ-RN or L-RN
8) Plated

For those that don't know:

The solution to chambering problems is to determine the cause:

Take the barrel out of the gun. Drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop round in barrel (or gage) and rotate it back-and-forth a few times.

Remove and inspect the round:

1) Scratches in the ink on bullet--COL is too long

2) Scratches in the ink on edge of the case mouth--insufficient crimp

3) Scratches in the ink just below the case mouth--too much crimp, you're crushing the case

4) Scratches in the ink on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit

5) Scratches in the ink on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.

 

[Hokie_PhD]

Since I'm not competing all of my range ammo is for practice and learning.

Like you Ive used factory loads for SD so I pick my range bullets by price. So I use the least expensive RMR 124gr. They've worked fine in all my guns so it's what I do!

 

[Laphroaig]

I just bought some of the MPR's to try out. I was going to get the Match Winners but changed at the last minute. I don't know why. I'm trying to find a good 9mm load so I'm still testing various combinations.

 

[2bfree]

With the RMR FMJ RN bullets, I was loading at 1.250" and they plunked and fed well in all of my guns, and I get why this is with different ogive angles, etc. I have no problem with understanding that part.

You sure about that 1.250

 

[Doublehelix]

You sure about that 1.250

UGH!!! Sorry! 1.125". I had .45's on my brain. I went back and edited my original post to avoid confusion. Thanks for catching that.

 

[Doublehelix]

In terms of accuracy, I find the rating as follows:
1) L-HBWC
2) JHP or L-SWC
3) FMJ-FN or L-CFP
4) FMJ-RN or L-RN
8) Plated

I have never used any type of wadcutter in 9mm, but I do use them occasionally in my .45.

For those that don't know:

The solution to chambering problems is to determine the cause:

Take the barrel out of the gun. Drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop round in barrel (or gage) and rotate it back-and-forth a few times.

Remove and inspect the round:

1) Scratches in the ink on bullet--COL is too long

2) Scratches in the ink on edge of the case mouth--insufficient crimp

3) Scratches in the ink just below the case mouth--too much crimp, you're crushing the case

4) Scratches in the ink on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit

5) Scratches in the ink on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.

I have seen this before, but it has been a while. Great post, thanks.

 

[Walkalong]

Why would one choose one of these 3 bullet types over another?

Makes no difference to many people, but a covered base in the JHP is one thing to consider.

 

[Walkalong]

Love that pic noylj.

 

[egd]

I have had the same curiosity as the OP. But I stated with RN and they work for me so I have never switched.
Just out of curiosity also, what are the pros and cons of a covered base?

 

[goldpelican]

Just out of curiosity also, what are the pros and cons of a covered base?

Less lead exposure while handling and while shooting.

 

[Dudedog]

Makes no difference to many people, but a covered base in the JHP is one thing to consider.

Less lead exposure while handling and while shooting.

One advantage of a covered base is no exposed lead to be vaporized by the burning powder charge.

The RN shot well for me the FNs a bit better but I will be using the MPR JHPs because I have had lead issues in the past. (traced to indoor range)
and I want to do everything possible to limit my lead exposure. I seem to be one of those people who just absorb any lead around.
RMRs FMJs like other FMJs do have exposed lead at the base.
Probably not an issue out doors, and I don't mind shooting the FMJs every now and then but since I tend to shoot a lot I need to do what I can about lead exposure.
The MPR JHPS do need to be seated short in some guns, something to be aware of. 1.08 is fine for me but othe people have reported needing to go as short as 1.04.
While I don't load my SD ammo the JHPs are inexpensive enough for everyday use, and could do double duty in case of a Zombie attack.

If it wasn't for my lead issues in the past I would probably use the FMJ-FNs, a little less money.
I prefer FN over RNs as I feel like I get a more consistent OAL.
(and I just find the shape more appealing)

I did do a quick velocity test on a couple different OALs with a mild charge of WSF,
I was not attempting to make 125 PF just to explore the change the OAL had on the velocity of the loads. (so I loaded light)
I had just got finished shooting a match and was pretty beat (107 ish outside when we finished)so I didn't try shooting any for accuracy.
Mixed Range Brass, S+B SP, 4.0gr WSF RMR 124gr MPR JHP
Charges as thrown by Lee autodrum after setting measure.
5" 9mm 1911
Temp 107 ish

Vel, PF, ME

OAL 1.08
981 121.64 265.04
966 119.78 257.00
977 121.15 262.89
955 118.42 251.18
948 117.55 247.51
Avg 965.40
Lo 948.00
Hi 981.00
ES 33.00
SD 14.05


OAL 1.065
975 120.90 261.81
989 122.64 269.38
960 119.04 253.82
988 122.51 268.84
976 121.02 262.35
Avg 977.60
Lo 960.00
Hi 989.00
ES 29.00
SD 11.80

OAL 1.055
992 123.01 271.02
983 121.89 266.12
987 122.39 268.29
977 121.15 262.89
1010 125.24 280.94
Avg 989.80
Lo 977.00
Hi 1010.00
ES 33.00
SD 12.56

OAL 1.04
989 122.64 269.38
1003 124.37 277.06
1012 125.49 282.06
995 123.38 272.66
1007 124.87 279.28
Avg 1001.20
Lo 989.00
Hi 1012.00
ES 23.00
SD 9.23

So going from 1.08 to 1.04 picked up about 36fps average.
The change would probably be larger if you were running a hotter load.

As a side note I would urge anyone who shoots at an indoor range get their lead levels checked if you haven't already
I am sure some indoor ranges are ok but for my personal experience and that of some other members there appear to be quite a few where the ventilation is inadequate.

 

[egd]

OK, thanks. I never thought about the lead exposure. I've never shot indoors so I'm probably ok with that. I've got a physical coming up in a month so I might get that checked just in case... What is it-a blood test?
I tried a few FP one time and I did like that the oal seemed more consistent, but I always thought that maybe, since there was no edge to snag on anything, a RN would enter the chamber easier if there was any misalignment during feeding.
Wow, 4.0 of WSF. My load is 4.5 at 1.135 with the RN. It has been a while since I worked that out and shot it though. I've been using 231/hp38 lately. Maybe I'll get some WSF out and revisit that.

 

[Doublehelix]

OK, thanks. I never thought about the lead exposure. I've never shot indoors so I'm probably ok with that. I've got a physical coming up in a month so I might get that checked just in case... What is it-a blood test?
I tried a few FP one time and I did like that the oal seemed more consistent, but I always thought that maybe, since there was no edge to snag on anything, a RN would enter the chamber easier if there was any misalignment during feeding.
Wow, 4.0 of WSF. My load is 4.5 at 1.135 with the RN. It has been a while since I worked that out and shot it though. I've been using 231/hp38 lately. Maybe I'll get some WSF out and revisit that.

If you look at DudeDog's numbers however, he is shooting some light loads there. Even his shortest cartridges barely make minor power factor. 4.0 gr. might be a good starting point to work up from.

 

[Doublehelix]

BTW, I tried plunk testing those RMR JHPs in my HK VP9 and SIG P938, and they failed at 1.125 (I expected it to be so). No problem, I will work out a new COAL that fires in all 3 guns.

 

[Walkalong]

I had to load them at 1.070 to plunk in my Shield. Shot very well at that OAL, especially in my Colt with a red dot sight that I could aim finely.

 

[Dudedog]

Lead level is a blood test, they just draw off another tube for it, don't know the cost my insurance covers it if the Dr asks for it.
Explain to your Doc why you want it.

My normal match load was 4.4gr of WSF with a 125 RMR plated FN, puts me right about 128-130 PF. Those are no longer available so I am working up a new one.
I backed down to 4 for the OAL test based on some past loads I had done using 147gr bullets, to make try to make sure I was ok at the shortest OAL. Again all the 4.0gr loads were to light to make 125 PF, even though the short ones at 1.04 were close.
To make PF with some margin I would guess about 4.2gr of WSF at 1.04 with the JHPs.
Guessing that will be about 1030-1040fps
Nice to see someone else uses WSF.
I tried it at first during the last powder shortage (and had to buy a 4lb jug-was hoping it wasn't a mistake at the time) because it was all I could get.
Didn't know then it would become my favorite for 9mm.
I really like it, seems to work well for me for light-medium to full power loads. Not quite as much velocity as some other powders at MAX but seems to shoot well. (at least for me)

Might be interesting to do a work up to MAX at 1.04 then load that charge at the different OALs.
Sigh, so many things I want to do, so little time.

(and sorry this is sort of off thread, don't mean to sidetrack)

 

[Walkalong]

They'll do it if you ask, just explain why you think you should.

 

[egd]

I will ask. My doc seems pretty nice. Last year was my first visit to him (old doc retired) and as we talked I found out he shoots a 44 or 41 ? mag for fun occasionally. He even gave me a script to help with my shakes-I'm old.
Since I know someone will ask, it was propanalol (sp?). I had to take a heart test first though. I only take it on the days I will shoot. It does help.

 

[vaalpens]

I think it really depends on your needs. For me it is not that difficult. When I pick a 9mm bullet I go with one that can do double duty in 9mm and 357sig. This obviously excludes the RN bullet for me. Both the FN and JHP bullets work well in 357sig, so I can go with either one of them. The FN bullet makes a neater hole for target shooting and it is cheaper, so most of the bullets I buy will be the FN variety. The JHP bullet especially the expanding bullet is great for shooting water jugs etc, plus I think you can push it harder since it does not have any exposed lead. So for me I will mostly buy FN bullets, then JHP for training and fun, and lastly the RN variety if they are very cheap.

 

[9mmepiphany]

UGH!!! Sorry! 1.125". I had .45's on my brain. I went back and edited my original post to avoid confusion. Thanks for catching that.

If you're loading your RN to 1.150 and you want to maintain internal case volume, you might try loading the FN to about 1.114"

 

[noylj]

One advantage of a covered base is no exposed lead to be vaporized by the burning powder charge.

But, lead is NOT vaporized by the burning powder charge—in fact, there is no time for the lead to even be heated by the burning gas. Recovered lead bullets prove this. Recovered lead bullets with the base painted with temper-lac prove this.
Lead exposure while shooting is primarily from the primer, then any gas cutting.

 

[Walkalong]

I'm not sure about that noylj, simple because the flame from rounds can and does eat the barrel up over time. I have to believe there is a slight bit of lead vaporized. All it would take would be extremely tiny amounts to add up indoors. If you fire one round and look at the barrel throats you can't see the damage from that one round either. Dunno, but many indoor ranges require bullets with no lead exposed on the base.

 

[Doublehelix]

If you're loading your RN to 1.150 and you want to maintain internal case volume, you might try loading the FN to about 1.114"

Thanks, but I am loading the JHPs not the FNs (at least for now). How did you do your math?

 

[9mmepiphany]

How did you do your math?

You compare the length of the bullets and subtract the difference from the OAL of your RN cartridge