Which is best, Gold Dot HP 115 gr. or 124 gr.?

[ACP]

My choice is 147 grain for reasons covered in this forum. I use Federal Hydra Shock and Golden Sabre. Nothing but premium stuff for my Robar R9.

Comments regarding  Glock are both humorous and true, in my experience.

Fiocchi, (which I love), is not a good choice for the R9. Admittedly, I have not shot Fiocchi in my R9 because of fear of a hot round.

[Richard S]

There was a chart posted a couple years ago showing the difference in expansion between 115 and 124gr gold dots fired from the R9. Basically the 115gr expanded perfectly and the 124gr didn't. I have a copy, but with my new service provider have no way to post it. If someone with posting ability will PM me with their email address, I will send them the picture for posting.

Rick

Here is the expansion chart Rick sent to me for posting:

[RickP]

Thank you Richard.  

Rick

[C0untZer0]

There are a lot of really good rounds in 124gr.  Winchester +P Bonded expand between .65 and .68 and have decent penetration (12" to 12.6").

Federal's 124gr +P EFMJ expand to about .590 and penetrate between 12"  in bare gel.

Of course these aren't usually tested out of a <3" barrel so I'm not exactly sure how they perform out of a Rohrbaugh R-9, but I think the best you can do is try to pick the best performing ammo you can, and see if it feeds reliably in you R-9.  The reasoning goes that the best performing rounds out of  a 5" will also be the best performing rounds out of a 2.9" barrel.

[Joe_from_NY]

There are a lot of really good rounds in 124gr.  Winchester +P Bonded expand between .65 and .68 and have decent penetration (12" to 12.6").

Federal's 124gr +P EFMJ expand to about .590 and penetrate between 12"  in bare gel.

Of course these aren't usually tested out of a <3" barrel so I'm not exactly sure how they perform out of a Rohrbaugh R-9, but I think the best you can do is try to pick the best performing ammo you can, and see if it feeds reliably in you R-9.  The reasoning goes that the best performing rounds out of  a 5" will also be the best performing rounds out of a 2.9" barrel.

We would hope you dont try these two in your R9 since they are +P.

[C0untZer0]

Well here is a larger set of ballistics data, you can discard the +P offerings.

http://demigodllc.com/~zak/firearms/fbi-pistol.php

To me, the 124 std pressure rounds don't look that great but they look better than most of the 115gr ballistics.

[yankee2500]

Here is the 9mm portion of the above referenced chart with the +P & +P+ removed.


[COLOR="Red"]This page offers different views of the FBI terminal ballistic testing data ("gelatin tests"). I started a discussion on The Firing Line, which is pretty interesting.

 
lbfps is momentum in units pound(mass)-feet-per-second.
ftlbs is energy in units foot-pounts(force).
cu is volume of wound cavity, in cubic inches.

Sorted by..
kinetic energy
momentum
(bare gelatin) penetration depth
(bare gelatin) wound volume
(clothed gelatin) penetration depth
(clothed gelatin) wound volume
Average wound volume for clothed and bare gelatin
Penetration over 30 inches in negatively sanctioned, and penetration over 20 inches is folded down to 20 inches.
Explanation of fields, example

 9x19    Win Ranger +P+  |115@1320, 21.7 mv, 444 E|BR  9.6", 0.53", 2.11cu|CL 10.2", 0.65", 3.37cu|avg 2.74, 3.89 re, 0.70
9x19 - caliber
Win Ranger +P+ - the name of the load
115@1320 - bullet mass in grains @ muzzle velocity
21.7 mv - bullet momentum in lb*fps
444 E - muzzle energy in ftlbs
BR - what follows is the data for bare gelatin
9.6" inches of penetration
0.53", final expanded diameter of bullet
2.11 cu, approximation of wound volume. (this does not take into account the expansion profile as a function of depth, but it should be roughly proportionate to actual wound volume)
CL - what follows is the data for clothed gelatin
same fields as the bare gelatin, as defined above
avg 2.74 - Average wound volume, clothed and bare gelatin
3.89 re - Free Recoil Energy, assuming a 1.88 lb pistol
0.70 - Average would volume per unit Free Recoil Energy. This is a measure of "bang for buck", and is discussed in the text below the data table.
 Sorted by s_none

9x19    Win Ranger Talon|147@ 864, 18.1 mv, 243 E|BR 13.8", 0.61", 4.03cu|CL 15.2", 0.59", 4.17cu|avg 4.10, 2.72 re, 1.51

9x19    Win Ranger Talon|147@1017, 21.4 mv, 337 E|BR 13.8", 0.66", 4.70cu|CL 15.5", 0.65", 5.14cu|avg 4.92, 3.77 re, 1.31

9x19    3-D             |115@1178, 19.4 mv, 354 E|BR 11.6", 0.54", 2.66cu|CL 13.9", 0.48", 2.52cu|avg 2.59, 3.10 re, 0.84

9x19    CCI/Speer GD    |115@1259, 20.7 mv, 404 E|BR 12.3", 0.67", 4.35cu|CL 22.1", 0.40", 2.78cu|avg 3.43, 3.54 re, 0.97

9x19    CCI/Speer GD    |115@1197, 19.7 mv, 365 E|BR 12.8", 0.67", 4.51cu|CL 22.6", 0.44", 3.44cu|avg 3.78, 3.20 re, 1.18

9x19    Fed Silvertip   |115@1091, 17.9 mv, 304 E|BR 10.1", 0.63", 3.13cu|CL 11.8", 0.58", 3.12cu|avg 3.13, 2.66 re, 1.18

9x19    CCI/Speer GD +P |124@1223, 21.7 mv, 411 E|BR 13.4", 0.68", 4.87cu|CL 20.2", 0.53", 4.47cu|avg 4.64, 3.88 re, 1.20

9x19    CCI/Speer GD    |124@1116, 19.8 mv, 342 E|BR 11.8", 0.69", 4.41cu|CL 22.0", 0.36", 2.24cu|avg 3.22, 3.23 re, 1.00

9x19    Rem             |124@1109, 19.6 mv, 338 E|BR 12.4", 0.60", 3.52cu|CL 13.7", 0.57", 3.50cu|avg 3.51, 3.19 re, 1.10

9x19    PMC/Eldorado SF |124@1118, 19.8 mv, 344 E|BR 10.7", 0.63", 3.32cu|CL 20.1", 0.41", 2.65cu|avg 2.98, 3.24 re, 0.92

9x19    CorBon XTP      |124@1123, 19.9 mv, 347 E|BR 13.9", 0.56", 3.44cu|CL 18.3", 0.46", 3.04cu|avg 3.24, 3.27 re, 0.99

9x19    Fed HydraShok   |147@ 935, 19.6 mv, 285 E|BR 13.6", 0.60", 3.85cu|CL 16.1", 0.52", 3.41cu|avg 3.63, 3.19 re, 1.14

9x19    Win Black Talon |147@ 946, 19.9 mv, 292 E|BR 14.8", 0.60", 4.20cu|CL 16.4", 0.61", 4.78cu|avg 4.49, 3.26 re, 1.38

9x19    Rem             |147@ 987, 20.7 mv, 318 E|BR 18.1", 0.51", 3.71cu|CL 15.9", 0.59", 4.36cu|avg 4.03, 3.55 re, 1.14

9x19    Hornady XTP     |147@ 918, 19.3 mv, 275 E|BR 22.1", 0.44", 3.36cu|CL 20.5", 0.46", 3.41cu|avg 3.18, 3.07 re, 1.04

9x19    Fed HydraShok   |147@ 995, 20.9 mv, 323 E|BR 21.4", 0.37", 2.30cu|CL 15.6", 0.60", 4.41cu|avg 3.28, 3.61 re, 0.91

9x19    Win Silvertip   |147@ 902, 18.9 mv, 265 E|BR 14.6", 0.53", 3.22cu|CL 18.1", 0.47", 3.14cu|avg 3.18, 2.97 re, 1.07

9x19    CCI/Speer GD+P  |124@1155, 20.5 mv, 367 E|BR 13.2", 0.62", 3.99cu|CL 16.1", 0.53", 3.55cu|avg 3.77, 3.46 re, 1.09

9x19    CCI/Speer GD    |124@1068, 18.9 mv, 314 E|BR 12.6", 0.59", 3.44cu|CL 17.5", 0.51", 3.57cu|avg 3.51, 2.96 re, 1.19

9x19    CCI/Speer GD    |147@ 924, 19.4 mv, 278 E|BR 14.8", 0.57", 3.78cu|CL 14.7", 0.55", 3.49cu|avg 3.63, 3.11 re, 1.17

9x19    Win Ranger PG   |124@1015, 18.0 mv, 283 E|BR 12.5", 0.65", 4.15cu|CL 14.0", 0.61", 4.09cu|avg 4.12, 2.67 re, 1.54

9x19    Win Ranger T    |147@1016, 21.3 mv, 337 E|BR 13.8", 0.66", 4.72cu|CL 15.7", 0.00", 0.00cu|avg 2.36, 3.76 re, 0.63
[/COLOR]

[kjtrains]

To all the above; that's a lot of good info; thanks!

[ACP]

Yankee: Wow. Are you seeking your PhD in ballistics?

[yankee2500]

I just copy & pasted what C0untZer0 posted the link to.

[C0untZer0]

To me the wounding ballistics of the 147gr rounds look more impressive.  You have penetration to around 14" and recovered diameters of around .60 cal

Here are some ballistics from a 3.4"  barrel which is as close as I've seen to the sub 3" in the R-9.

http://www.firearmstactical.com/briefs9.htm

The regular 124gr Gold Dots are only penetrating 12.6" and expanding to 0.59

The 147gr Gold Dots were penetrating to 14.8" with a little less expansion - averaging .57"

The 115gr Gold Dots were pentrating to 12.8" with  more expansion - averaging .67"

[yankee2500]

I don't think there is a significant result difference in 12.6" or 14.8" as that is all the way through the average person on a frontal shot, and certainly deep enough to hit vitals on the biggest bad guy.
   I would feel very comfortable with any one of those Gold Dot rounds.

[C0untZer0]

Well the 14" penetration is kind of a goal that you shoot for in ballistics (pun intended).  

The 14" is not necessarily to be taken literally - meaning that anyone really thinks that to stop all BGs you have to put a 14" channel through them.

Rather, the 14" penetration in gel correlates to overall good performance under the widest circumstances.  Your round may go into a BGs forearm or bicep... you may need a round that can go through an arm and still penetrate the torso.  BG may be a weight lifter with 3" pecs and facing you at a 45 degree angle...  you may need to fire through a ski jacket, sweater and cotton shirt, you may need to fire through a leather jacket...  the 14" goal is a predictor of overall performance.

But having said that, if someone takes their R-9 to the range and a 147gr round or even a 124gr round makes the R-9 feel flippy to them, or they just don't like the way shooting a particular round feels... then they have to go with what they think is best.

You're better off shooting a 115gr round that you can shoot well than a 147gr round that you can't