do 147gr 9mm bullets "slap the steel" any harder?

[VforVandetta]

Not sure where else to put this:

 

So up to this point in my shooting "career" I would basically run the cheapest 115 grain 9mm for practice and then some decent factory ammo like blazer or federal or fiochi in matches. 

 

This year it seems like federal is pumping out 124/147 gr ammo for pretty decent prices so ive been running that, and mostly sticking with 124gr lately just cuz i was able to score a good deal on a couple cases and its just a bit cheaper than the 147 in general. 

 

last couple matches I hit a popper or 2 that didnt fall probably because i just knicked the edge or whatever...but accuracy and target calibration issues aside, is there aaaaannnny little edge/advantage when it comes to the 147 in terms of hitting a steel target with more force?

 

ive never reloaded and only have a pretty passive interest in the nuances of ammo so this might be a stupid question thanks in advance for any help. 

 

 

[Sarge]

6 hours ago, VforVandetta said:

Not sure where else to put this:

 

So up to this point in my shooting "career" I would basically run the cheapest 115 grain 9mm for practice and then some decent factory ammo like blazer or federal or fiochi in matches. 

 

This year it seems like federal is pumping out 124/147 gr ammo for pretty decent prices so ive been running that, and mostly sticking with 124gr lately just cuz i was able to score a good deal on a couple cases and its just a bit cheaper than the 147 in general. 

 

last couple matches I hit a popper or 2 that didnt fall probably because i just knicked the edge or whatever...but accuracy and target calibration issues aside, is there aaaaannnny little edge/advantage when it comes to the 147 in terms of hitting a steel target with more force?

 

ive never reloaded and only have a pretty passive interest in the nuances of ammo so this might be a stupid question thanks in advance for any help. 

 

 

If you will do a search you will find page after page on the subject. It gets pretty nerdy with energy dwell times blah blah but in the end steel has to fall if you hit it properly with a legal PF round. 

[4n2t0]

Down the rabbit hole you go...

 

 

My experience and eyes tell me that knocking down steel with a 147gr bullet is easier. That's as scientific as I get.

[SnipTheDog]

If Force = Mass * Acceleration

147gr * 1096ft/s = 161,112grft/s - Titegroup 3.6g
115gr * 1151ft/s = 132,365grft/s -   Titegroup 4.3gr

 

Then 147gr has 28kgrft/s more oomph than 115gr whatever that means.  147gr slaps!

[Guy Neill]

Snip - those look to be momentums (m x v) than force (m x a)

 

 

[Guy Neill]

Hitting the steel higher (with whatever) will also increase the chance of knocking it down. Years ago, when Tommy Campbell was using the Wonder-nine against all the Major caliber stuff, he would shoot the upper tab of a popper to better put it down.

[SnipTheDog]

12 minutes ago, Guy Neill said:

Snip - those look to be momentums (m x v) than force (m x a)

 

 

You're right.  Don't have good acceleration values.

[Guy Neill]

And if you divide by 1,000 you get power factor.

 

[Guy Neill]

I took a little different comparison. What if the power factor was the same? I came up with;

BW     BV        PF        F

115     1151     132.4    901

124    1065    132.3    833

147     900    132.1     705

[VforVandetta]

4 hours ago, Guy Neill said:

Hitting the steel higher (with whatever) will also increase the chance of knocking it down. Years ago, when Tommy Campbell was using the Wonder-nine against all the Major caliber stuff, he would shoot the upper tab of a popper to better put it down.

Ah nice. Didn't even consider that seems so obvious once you say it lol

[Guy Neill]

One other factor is the bullet hardness.

 

Before chronographs were used, Cooper (then president of IPSC) had "Peter the Power Meter" to determine the ammunition power. It was a ballistic pendulum with a steel bob. It was calibrated by shooting it with 230gr Ball from a Commander.

 

A couple of shooters (Finke? for one. cast bullets from pewter that is much harder than lead or lead core (most everyone shot cast bullets back then)). The hard pewter bullets flipped Peter the Power Meter, so it was retired, and we went with the power factor method to determine ammunition power.

[Sarge]

4 hours ago, VforVandetta said:

Ah nice. Didn't even consider that seems so obvious once you say it lol

Also obvious that shooting above the calibration zone is much more difficult, not to mention unnecessary. It will needlessly slow you down.

[VforVandetta]

21 hours ago, Guy Neill said:

One other factor is the bullet hardness.

 

Before chronographs were used, Cooper (then president of IPSC) had "Peter the Power Meter" to determine the ammunition power. It was a ballistic pendulum with a steel bob. It was calibrated by shooting it with 230gr Ball from a Commander.

 

A couple of shooters (Finke? for one. cast bullets from pewter that is much harder than lead or lead core (most everyone shot cast bullets back then)). The hard pewter bullets flipped Peter the Power Meter, so it was retired, and we went with the power factor method to determine ammunition power.

 

thank for the info. Also, I read that in like an old civil war documentary narrator voice in my head. 

[Guy Neill]

I finally remembered - it was Charlie Funke and a shooting buddy that did the pewter bullets.

[NoSteel]

When I moved from 115gr to 160gr for 9mm I simplified the logic.  Would you rather be hit by a bicycle while crossing the road or by a bus??   Ok Ok,  just adding some humor since this question has sparked so much controversy in the past!! LOL…

[VforVandetta]

On 9/9/2024 at 9:01 PM, 4n2t0 said:

Down the rabbit hole you go...

 

 

My experience and eyes tell me that knocking down steel with a 147gr bullet is easier. That's as scientific as I get.

This helped. Thanks

[Joe4d]

On 9/9/2024 at 9:32 PM, SnipTheDog said:

If Force = Mass * Acceleration

147gr * 1096ft/s = 161,112grft/s - Titegroup 3.6g
115gr * 1151ft/s = 132,365grft/s -   Titegroup 4.3gr

 

Then 147gr has 28kgrft/s more oomph than 115gr whatever that means.  147gr slaps!

nobody is running 147's at 1096 feet per second.  The question really is will 147's knock down steel better when loaded to the same power factor as a 124 or 115...  

Old school power factor was originally calculated by hitting a steel pendulum and seeing how far it swung when hit. "minor" was calibrated using basic 9mm ball,, probably 124's back then,, and major with 45acp ball.

I would think bullet design has an affect ( effect ?)  as well.. A bullet that hits and mushrooms and falls down, will transfer more energy than one that bounces , ricochets  or fragments in all directions.