Montana Gold FMJ vs. JHP (9MM) Accuracy


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tts
December 28, 2011, 08:57 PM
I'm looking to purchase a large quantity of Montana Gold 9MM FMJ or JHP bullets for reloading.

I've read that the manufacturing process of JHPs lends to more accuracy. What are your thoughts?

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bds
December 28, 2011, 09:09 PM
For 9mm, especially if you plan on using less than max load data, I would definitely recommend the heavier 124 gr bullet over the lighter 115 gr bullet as you'll have easier time cycling the slide of your pistols especially with lighter target loads.

As to FMJ vs JHP accuracy, without having done any accuracy testing in your pistol with different powders, I would suggest going with the FMJ (conducting range tests would be the only way to determine accuracy difference between the two bullets in your pistols with particular powder/charges). With the FMJ RN bullet, you will have less feeding/chambering issues and the exposed lead base will expand easier with the lighter target loads to maintain consistent chamber pressures for more consistent shot group accuracy.

Also, the Montana Gold 124 gr FMJ bullet ($106/1K) costs less than the 124 gr JHP bullet ($114/1K), so on cost basis, it would be a no brainer. ;)

Bovice
December 28, 2011, 09:16 PM
The cost difference between the two isn't much. Get the JHPs if you think they will help. A lot of people shoot their FMJs and a lot of people shoot the JHPs. If you want the ultimate in reliability, I would use FMJs regardless of whether or not the gun seems to care one way or another for 9mm. In .40 S&W it doesn't matter because the FMJs are flat nosed anyway, and if it can't feed JHPs it probably isn't feeding the FMJs either.

I have heard that the adage of JHPs being more accurate was from the days when JHPs were the only bullets around without an exposed lead base. Now, you can get TMJs. Montana gold has those too.

1SOW
December 28, 2011, 11:12 PM
I have heard that the adage of JHPs being more accurate was from the days when JHPs were the only bullets around without an exposed lead base. Now, you can get TMJs. Montana gold has those too.

IF you believe more bullet contact with the rifling contributes to accuracy in a semi-auto, then the JHP has more accuracy.

tts
December 29, 2011, 01:50 AM
Sounds good! I'm set on the FMJs -- thanks all for your help!

Does anyone want some of them? I'll probably get 4 cases to save on the cost.

Price would be about $.08 per bullet + flat rate USPS shipping ($5-$10).

If so, reply or PM me.

bds
December 29, 2011, 05:59 AM
I've read that the manufacturing process of JHPs lends to more accuracy. What are your thoughts?
For the same weight bullets, due to the hollow space in the nose, JHP bullet will have longer base (bearing surface) to engage the rifling and stabilize the bullet. Although this may help, this factor alone won't necessarily translate to greater accuracy as shot group accuracy is the result of several reloading variables.

Ultimately, accuracy will benefit from more consistent muzzle velocities. More consistent muzzle velocities will result from more consistent chamber pressures. For me in theory, more consistent chamber pressures will result from (and taking into consideration the use of mixed head stamp range brass resized with slight variations in case lengths and condition of brass by manufacture and usage/work hardening):

1. Consistent bullet weight
2. Consistent powder charge
3. Consistent primer ignition
4. Consistent neck tension
5. Minimized high pressure gas leakage

1. Bullet weight. For me, accuracy is everything and have spent my early years of match shooting hand weighing bullets to sort by exact weight. Not anymore, as I learned other reloading variables like powder charge variations trump slight variations in bullet weight. :D Montana Gold (and many other quality/premium jacketed/plated) bullets will vary less than 1 grain bullet-to-bullet and I have used this as my standard for consistency in jacketed/plated bullets.

2. Powder charge. I use 1/10 grain variation or less for charge-to-charge consistency and most small ball/flake powders like Bullseye/Titegroup/WST/W231/HP-38/Universal/WSF/AutoComp will produce this level of consistency.

3. Primer ignition. I have used Winchester SP/LP exclusively over the years but tried Magtech/PMC SP and Wolf/Tula LP primers (bronze/brass colored cups) during "primer shortage" in recent years with happy results (exception being silver/nickel colored lot of Tula SP primers I am currently having ignition issues with (http://www.thehighroad.org/showthread.php?p=7805786#post7805786)).

4. Neck tension. This is where the length of bullet base may come into play as longer JHP bullet base will be seated deeper in the case neck resulting in greater neck tension and producing slightly higher chamber pressures/muzzle velocities using the same powder charge/OAL as FMJ bullet. Some USPSA match shooters I have shot with, in pursuit of absolute economy of reloading, will often use Titegroup/JHP bullet combination, but not necessarily for accuracy as long as the load met power factor minimums (most match shooters simply developed/adjusted their load's OAL/powder/charges until they achieved a certain level of acceptable accuracy/PF regardless of bullet types used).

5. High pressure gas leakage. Longest OAL that will reliably feed/chamber in your pistol/barrel/magazine will reduce gas leakage along with the use of .355" (for 9mm, .400" for 40S&W) groove diameter barrels with shorter leade/start of rifling for more consistent chamber pressures.

Keep in mind that many shooters also prefer the use of JHP bullets for the purposes of reduced smoke and/or lead exposure issues. So if you have these concerns, it will affect your bullet selection.

In the end, it will probably come down to your barrel's groove diameter, leade length and start of rifling as to whether you would benefit more from FMJ's exposed lead base's ability to expand to seal with the barrel vs deeper seated JHP to produce more consistent chamber pressures (so slug your barrel to find out what the groove diameter is). For me, holes on target speak volumes. It would be nice to range test both bullet types in your pistol before you made a large purchase. Perhaps you could call Montana Gold and ask if you can obtain a bullet sample?

bds
December 29, 2011, 06:30 AM
FYI, Atlanta Arms & Ammo (http://www.atlantaarmsandammo.com/MATCH_AMMO/match_ammo.html) produces match ammunition used by team Glock/Dave Sevigny and US Army Marksmanship Unit:


9MM 115GR FMJ Match AMU - Army Marksmanship Unit
"Using a Sierra Bullet and Starline brass, this is designed for extreme accuracy at 50 yards. This is the ammo used by the Army Marksmanship Unit and the Marine team for service pistol matches. Our accuracy test requirement is 5 ten-shot groups at 50 yards with an average group size not to exceed 1.5 inches, when shot from a test fixture."

9MM 115GR XTP Match PPC - PPC Matches/Bianchi Cup/Steel Challenge
"Using a Hornady bullet and Starline brass, this is designed for extreme accuracy at 50 yards. This ammo is the PPC match ammo used by all of Homeland Security pistol teams including all of the Border Patrol Teams, as well as some of the best police teams. This is also a great Bianchi Cup and Steel Challenge round averaging 1100 FPS. Our accuracy test requirement is 5 ten-shot groups at 50 yards, with an average group size not to exceed 1.25 inches."

9MM 147GR JHP G Match - Glock Shooting Team/USAMU Action Pistol Team
"Using a Zero bullet and Starline brass, this is designed to make minor power factor. This ammo was originally designed for the Glock shooting team, and is also used by the AMU Action Pistol Team. If you are shooting a production class or any type of shooting where a minor power factor is desired, this is the ammo of choice."

40 S&W 180GR FMJ - Major Power Factor
"Using a Zero bullet and Starline brass, this is designed to make major power factor. This ammo averages 950 FPS out of our G22 test gun giving a 170 power factor."

40 S&W 180GR FMJ - Major Power Factor, USAMU Action Pistol Team/STI
"Using a Zero bullet and Starline brass, this major power factor ammo was originally designed for the AMU Action pistol team and STI."

Marlin 45 carbine
December 29, 2011, 11:25 AM
I have'nt tryed the Montana fmj but have the jhp they did as well as anything except Remmy GS 124gr jhp
crude expansion testing showed great results also.

REL1203
December 29, 2011, 01:39 PM
I have ordered a case of both actually. with FMJ, my guns liked 4.5g of Universal, with JHP, my guns liked 4.2/4.3g of Universal. I tended to like the JHP better, and when i order some in the next month, i am going with the JHP myself, but the FMJs worked extremely well.

bds
December 29, 2011, 02:32 PM
REL1203/tts, maybe you guys could work something out so they can be range tested for side-by-side accuracy comparison in tts' pistol before he makes a large purchase. ;)

1SOW
December 29, 2011, 09:15 PM
IF you believe more bullet contact with the rifling contributes to accuracy in a semi-auto, then the JHP has more accuracy.


bds knows what he's talking about.
I have very good results with the MG 124CMJ bullets, and actually don't favor the conical nose of the MG 124JHP for other than accuracy concerns.

On the other hand, the Zero 125jhp with a traditional ogive is one of my favorite loads for my pistols. Not the greatest accuracy available, but a very consistent load. Neither of the two JHPs are designed specifically for SD.

If bearing surface can contribute to accuracy, the Berry's 124gr HBRN has LOTS of bearing surface in this very long .619" bullet with a hollow base that allows using standard oals. It does shoot well with my 130pf loads. Might be a winner loaded for best groups.

Reloading is a great hobby.

His idea to do some bullet comparison/ swapping for tests is excellent. Both parties win.

bds
December 29, 2011, 09:47 PM
+1 on the HBRN-TP bullets as 124 HBRN load is outshooting my reference 115 gr Winchester FMJ load of 4.8 gr W231/HP-38 loaded to 1.125"-1.135" OAL. BTW, TP (Thick Plating) bullets can be driven to 1450 fps.

Here are Berry's 124 RN, 124 HBRN-TP, 115 HBRN-TP and Winchester 115 FMJ for bearing surface length comparison. I think their better-than-jacketed accuracy comes from the longer bearing surface length and the hollow base that expands better to produce more consistent chamber pressures.

http://www.thehighroad.org/attachment.php?attachmentid=142158&stc=1&d=1305395802

Philippe
December 29, 2011, 10:15 PM
I love their 124gr FMJ's on top of Power Pistol, very reliable and accurate out of my G19.

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