# Recoil energy: Comparing 9mm 115gr vs. 124gr vs. 147gr

Discussion in 'Caliber Corner' started by coal, Jan 10, 2010.

1. ### coal

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I freely admit I ate some crow in an earlier thread regarding recoil energy (mainly) because I had the wrong velocities ingrained in my memory for 115gr and 124gr. I did a little research, and thought I'd share it here.

The short, inconvienient answer: Recoil really depends mostly on how fast each relative object being compared is moving.

The crow I ate was because: I did not realize just how "weak" many current 9mm target factory loadings had become for 115gr and 124gr.

Concern I then shared: Folks shoot "weak" factory 115gr (~1150fps) or 124gr (~1050fps) target loads thinking "Sweet, light recoil", then load up that 124gr +p (~1250fps) defensive load and have a slightly different experience. This does not occur w/ 147gr.

Numbers I ran using factory data to satisfy my curiousity:

Weight = Velocity = Free Recoil Energy in ft/lbs

Blazer FMJ
115 = 1145 = 7.14
124 = 1090 = 7.39
147 = 950 = 7.76

Federal FMJ
115 = 1180 = 7.53
124 = 1150 = 8.13
147 = 1000 = 8.50

Federal HST
115 = N/A
124 = 1150 = 8.13
147 = 1000 = 8.50
124 +p = 1200 = 8.77
147gr +p = 1050 = 9.28

S&B FMJ
115 = 1287 = 8.78
124 = 1188 = 8.62
147 = N/A

Remington GSHP
115 = 1180 = 7.53
124 = 1125 = 7.82
147 = 990 = 8.35

Remington Express
115 = 1250 = 8.33
124 = 1100 = 7.52
147 = 990 = 8.35

Gold Dot
115 = 1210 = 7.87
124 = 1220 = 9.04
147 = 985 = 8.28

Winchester FMJ
115 = 1190 = 7.64
124 = 1140 = 8.01
147 = 990 = 8.35

Winchester Ranger T-Series
115 = N/A
124 = 1250 = 9.44
147 = 990 = 8.35

Winchester Ranger JHP
115 = 1335 = 9.37
115 = 1225 = 8.04

Double Tap
115 +p = 1415 = 10.40
124 +p = 1310 = 10.27
147 +p = 1135 = 10.69

Fiocchi FMJ
115 = 1260 = 8.45
124 = 1180 = 8.26
147 = 1000 = 8.50

MagTech
115 = 1155 = 7.25
115gr +p = 1328 = 9.28
124 = 1109 = 7.62
147 = 990 = 8.35

Wolf
115 = 1150 = 7.19
124 = 1130 = 7.88
147 = 985 = 8.28

PMC FMJ
115 = 1160 = 7.30
124 = 1110 = 7.64
147 = N/A

Sorted by Free Recoil Energy:
Make, Weight, Velocity Recoil (ft/lbs)
Blazer FMJ 115 1145 7.14
Wolf 115 1150 7.19
MagTech 115 1155 7.25
PMC FMJ 115 1160 7.30
Blazer FMJ 124 1090 7.39
Remington Express 124 1100 7.52
Federal FMJ 115 1180 7.53
Remington GSHP 115 1180 7.53
MagTech 124 1109 7.62
Winchester FMJ 115 1190 7.64
PMC FMJ 124 1110 7.64
Blazer FMJ 147 950 7.76
Remington GSHP 124 1125 7.82
Gold Dot 115 1210 7.87
Wolf 124 1130 7.88
Winchester FMJ 124 1140 8.01
Winchester Ranger JHP 115 1225 8.04
Federal FMJ 124 1150 8.13
Federal HST 124 1150 8.13
Fiocchi FMJ 124 1180 8.26
Gold Dot 147 985 8.28
Wolf 147 985 8.28
Remington Express 115 1250 8.33
Remington GSHP 147 990 8.35
Remington Express 147 990 8.35
Winchester FMJ 147 990 8.35
Winchester Ranger T-Series 147 990 8.35
MagTech 147 990 8.35
Fiocchi FMJ 115 1260 8.45
Federal FMJ 147 1000 8.50
Federal HST 147 1000 8.50
Fiocchi FMJ 147 1000 8.50
S&B FMJ 124 1188 8.62
Federal HST 124 1200 8.77
S&B FMJ 115 1287 8.78
Gold Dot 124 1220 9.04
Federal HST 147 1050 9.28
MagTech 115 1328 9.28
Winchester Ranger JHP 115 1335 9.37
Winchester Ranger T-Series 124 1250 9.44
Double Tap 124 1310 10.27
Double Tap 115 1415 10.40
Double Tap 147 1135 10.69

Notes & Assumptions:
Recoil Calculator
Velocity pulled from manufacturer website today
115gr = 4.6gr powder*
124gr = 4.4gr powder*
147gr = 4.2gr powder*
1lb = handgun weight
*Manufactures don't list powder charge weight. I suspect slight variations and more velocity to come from more of the same powder, or same/less of a faster powder. And, heavier bullets use less powder as they have less remaining case volume and greater weight. Still, differences of 0.xgr in powder amounts will not skew results significantly.

Observations:
If the 147gr is traveling at 950fps:
- 115gr needs to be traveling >1214fps
- 124gr needs to be traveling >1126fps
for the 147gr to have less recoil.

If the 124gr is traveling at 1050fps:
- 115gr needs to be traveling >1132fps
for the 124gr to have less recoil.

Others:
147gr vs. 115gr
If 147 = 900 , then 115 velocity > 1150 fps
If 147 = 925 , then 115 velocity > 1182 fps
If 147 = 950 , then 115 velocity > 1214 fps
If 147 = 975 , then 115 velocity > 1246 fps
If 147 = 1000 , then 115 velocity > 1278 fps
If 147 = 1025 , then 115 velocity > 1310 fps
If 147 = 1050 , then 115 velocity > 1342 fps
If 147 = 1075 , then 115 velocity > 1374 fps
If 147 = 1100 , then 115 velocity > 1406 fps
147gr vs. 124gr
If 147 = 900 , then 124 velocity > 1067 fps
If 147 = 925 , then 124 velocity > 1097 fps
If 147 = 950 , then 124 velocity > 1126 fps
If 147 = 975 , then 124 velocity > 1156 fps
If 147 = 1000 , then 124 velocity > 1185 fps
If 147 = 1025 , then 124 velocity > 1215 fps
If 147 = 1050 , then 124 velocity > 1245 fps
If 147 = 1075 , then 124 velocity > 1274 fps
If 147 = 1100 , then 124 velocity > 1304 fps
124gr vs. 115gr
If 124 = 1050 , then 115 velocity > 1132 fps
If 124 = 1075 , then 115 velocity > 1159 fps
If 124 = 1100 , then 115 velocity > 1186 fps
If 124 = 1125 , then 115 velocity > 1213 fps
If 124 = 1150 , then 115 velocity > 1240 fps
If 124 = 1175 , then 115 velocity > 1267 fps
If 124 = 1200 , then 115 velocity > 1294 fps
If 124 = 1225 , then 115 velocity > 1321 fps
If 124 = 1250 , then 115 velocity > 1348 fps
If 124 = 1275 , then 115 velocity > 1375 fps
If 124 = 1300 , then 115 velocity > 1402 fps
If 124 = 1325 , then 115 velocity > 1429 fps
If 124 = 1350 , then 115 velocity > 1456 fps

Last edited: Jan 18, 2010
ScottR65 likes this.
2. ### pimuk

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Thanks, Coal.

I have got a Chrono, therefore I have made my own conclusion on perceived recoil, shootibility and accuracy of all loads I use. I tend to shoot fast with muscle memory so recoil impulse characteristic is something I am serious about. And I tend to shoot far as well so I am a bit paranoi dabout 50-meter accuracy.

I wish everyone, if serious, does each own test of the carry load(s). I don't worry about reliability because U.S. made loads are too good to be false.

For me, 147 gr at 960-980 fps is easiest to control, followed by the 115/1,220-1,260, 124/1,150-1,200 and 127/1,233-1,260. Those are real world velocity ranges, measured at 15 feet from the muzzle. (They varied based mainly on light intensity).

S&B .40, 180/931 has more recoil than all abovementioned loads. Speer Lawman clocked at 970 fps give discernable more recoil.

Last edited: Jan 11, 2010

3. ### 481

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Awesome list, cole!

If you wish to calculate momentum equivalence between two bullet weights at two different respective muzzle velocities, there is a quick and easy way to do so.

A simple rearrangement of the equation M1V1 = M2V2 (the expression of Newton's "Conservation of Momentum") will provide the exact numbers.

Solving for "V2" we get:

M1V1/M2 = V2

An example:

What velocity must a 115 gr. bullet have in order to possess the exact same momentum as a 147 gr. bullet with a velocity of 1,000 fps?

So, we "plug in" the numbers and we get...

M147 x V147 / M115 = V115

147 x 1,000 / 115 = V115

147,000 / 115 = V115

1278.261 = V115

Therefore, a 115 gr. bullet with a velocity of 1,278.261 fps will have the same momentum as a 147 gr. bullet with a velocity of 1,000 fps.

I hope this provides a useful option for those who'd like to repeat the math used to compare the momentum of different bullet weights and velocities.

BTW, did you calculate your results above "by hand" (using the equation) or just run them through the 'site's calculator?

Last edited: Jan 11, 2010
4. ### coal

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Here's the list via formula
"Free Recoil Energy" = ((Mbullet x Vbullet + 4700 x Mpropellant) ÷ 7000))² ÷ (64.34809711) ÷ (Mfirearm)
using data above with same "Notes & Assumptions":

Sorted List:

115gr 1145fps 7.45
115gr 1150fps 7.51
115gr 1155fps 7.57
115gr 1160fps 7.62
124gr 1090fps 7.70
124gr 1100fps 7.83
115gr 1180fps 7.85
124gr 1109fps 7.94
124gr 1110fps 7.95
115gr 1190fps 7.96
147gr 950fps 8.06
124gr 1125fps 8.14
115gr 1210fps 8.20
124gr 1130fps 8.20
124gr 1140fps 8.33
115gr 1225fps 8.37
124gr 1150fps 8.46
147gr 985fps 8.59
147gr 990fps 8.66
115gr 1250fps 8.67
115gr 1260fps 8.79
147gr 1000fps 8.82
124gr 1180fps 8.85
124gr 1188fps 8.95
124gr 1200fps 9.11
115gr 1287fps 9.13
124gr 1220fps 9.38
147gr 1050fps 9.61
115gr 1335fps 9.73
124gr 1250fps 9.79
124gr 1301fps 10.64
115gr 1415fps 10.78
147gr 1135fps 11.04

Raw List:

115gr
((115*1145+4700*4.6)/(7000))*((115*1145+4700*4.6)/(7000))/(64.34809711)/(1)
7.4528810692894531088479420539341
((115*1180+4700*4.6)/(7000))*((115*1180+4700*4.6)/(7000))/(64.34809711)/(1)
7.8493932385275306981880416336313
((115*1287+4700*4.6)/(7000))*((115*1287+4700*4.6)/(7000))/(64.34809711)/(1)
9.1253164245897557022061051259197
((115*1250+4700*4.6)/(7000))*((115*1250+4700*4.6)/(7000))/(64.34809711)/(1)
8.673245994456479765709936798852
((115*1210+4700*4.6)/(7000))*((115*1210+4700*4.6)/(7000))/(64.34809711)/(1)
8.1974397800558078269069442953257
((115*1190+4700*4.6)/(7000))*((115*1190+4700*4.6)/(7000))/(64.34809711)/(1)
7.9645698838681729005816433098199
((115*1335+4700*4.6)/(7000))*((115*1335+4700*4.6)/(7000))/(64.34809711)/(1)
9.7288990892328647879034414554987
((115*1225+4700*4.6)/(7000))*((115*1225+4700*4.6)/(7000))/(64.34809711)/(1)
8.3742942320145907279967554634426
((115*1415+4700*4.6)/(7000))*((115*1415+4700*4.6)/(7000))/(64.34809711)/(1)
10.777820264279762164982534943526
((115*1260+4700*4.6)/(7000))*((115*1260+4700*4.6)/(7000))/(64.34809711)/(1)
8.7942947193119398516924329523408
((115*1155+4700*4.6)/(7000))*((115*1155+4700*4.6)/(7000))/(64.34809711)/(1)
7.5651216748726863694470964914726
((115*1150+4700*4.6)/(7000))*((115*1150+4700*4.6)/(7000))/(64.34809711)/(1)
7.508896513518305134083431871323
((115*1160+4700*4.6)/(7000))*((115*1160+4700*4.6)/(7000))/(64.34809711)/(1)
7.6215565533525968149389359143829

124gr
((124*1090+4700*4.4)/(7000))*((124*1090+4700*4.4)/(7000))/(64.34809711)/(1)
7.7024003882508174781743593286474
((124*1150+4700*4.4)/(7000))*((124*1150+4700*4.4)/(7000))/(64.34809711)/(1)
8.4554007247282142700191749718869
((124*1200+4700*4.4)/(7000))*((124*1200+4700*4.4)/(7000))/(64.34809711)/(1)
9.1097219622099832922633695628568
((124*1188+4700*4.4)/(7000))*((124*1188+4700*4.4)/(7000))/(64.34809711)/(1)
8.9504611640452176554261587175602
((124*1125+4700*4.4)/(7000))*((124*1125+4700*4.4)/(7000))/(64.34809711)/(1)
8.1373836140841269278880486610396
((124*1100+4700*4.4)/(7000))*((124*1100+4700*4.4)/(7000))/(64.34809711)/(1)
7.8254621755045710317509030066173
((124*1220+4700*4.4)/(7000))*((124*1220+4700*4.4)/(7000))/(64.34809711)/(1)
9.3782776099149661206743057344409
((124*1140+4700*4.4)/(7000))*((124*1140+4700*4.4)/(7000))/(64.34809711)/(1)
8.327462399822835559647446768777
((124*1250+4700*4.4)/(7000))*((124*1250+4700*4.4)/(7000))/(64.34809711)/(1)
9.7884258879498780984834867795271
((124*1310+4700*4.4)/(7000))*((124*1310+4700*4.4)/(7000))/(64.34809711)/(1)
10.635055747338477900795845305456
((124*1180+4700*4.4)/(7000))*((124*1180+4700*4.4)/(7000))/(64.34809711)/(1)
8.8450675446263005892885810113848
((124*1109+4700*4.4)/(7000))*((124*1109+4700*4.4)/(7000))/(64.34809711)/(1)
7.9370516719713771317817688705891
((124*1130+4700*4.4)/(7000))*((124*1130+4700*4.4)/(7000))/(64.34809711)/(1)
8.200499382447781880634755470695
((124*1110+4700*4.4)/(7000))*((124*1110+4700*4.4)/(7000))/(64.34809711)/(1)
7.9494992702886496166864835896152

147gr
((147*950+4700*4.2)/(7000))*((147*950+4700*4.2)/(7000))/(64.34809711)/(1)
8.0573151854622107876656680827216
((147*1000+4700*4.2)/(7000))*((147*1000+4700*4.2)/(7000))/(64.34809711)/(1)
8.8175474564550025432756732532382
((147*1050+4700*4.2)/(7000))*((147*1050+4700*4.2)/(7000))/(64.34809711)/(1)
9.6120464750134706819460134926125
((147*990+4700*4.2)/(7000))*((147*990+4700*4.2)/(7000))/(64.34809711)/(1)
8.6627596624511900815088454136262
((147*985+4700*4.2)/(7000))*((147*985+4700*4.2)/(7000))/(64.34809711)/(1)
8.5858797666627689963713365198532
((147*1135+4700*4.2)/(7000))*((147*1135+4700*4.2)/(7000))/(64.34809711)/(1)
11.041336992226093816809060882578

5. ### 481

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cole,

My question above was more of a "Yes" or "No" type of question.

It is clear that you understand the equation, but I needed no proof of that and hope that you didn't go to too much trouble to post the data that you did although it would appear that such is the case.

In any event, it looks as if you have put your usual touch upon the pursuit and calculated just about every concievable 9mm arrangement that one might encounter.

Nice job.

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7. ### NG VI

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That's pretty cool, thanks for the time!

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