9mm 115 and other weights

Majicmike

Majicmike

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Why do most guys shoot 124 or 147.
Being a novice to comp shooting is there really any benifit. I've shot all and I can't tell a difference in any of it.
 
Heavier bullets knock down steel more reliably than lighter ones
Heavier bullets go slower, so you might not get a sonic crack - I like that, it might not matter to you.
 
Catfish said:
Heavier bullets knock down steel more reliably than lighter ones
Heavier bullets go slower, so you might not get a sonic crack - I like that, it might not matter to you.
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I was wondering which worked better ons poppers. A slower heavy bullet vs a fast lighter one. Is there any recoil difference? ( factory loads)
 
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Heavy projectiles and fast powder give more of a push recoil impulse as opposed to a snappy muzzle flip. In my opinion, it’s an easier impulse to control for a faster follow up shot. I also agree with @Catfish that the heavier variety put steel down more reliably.
 
Beats me.

All I've ever shot out of my Beretta 92FS is 115 grain. Even my carry ammo is Gold Dot 115 gr.

It's accurate and cycles reliably.
 
I shot a couple boxes of 115 and then a couple WWB 124 NATO thru the tiny Sig. In such a light gun, the difference is noticeable.
 
Go open the door to your safe. Back off and swing at it with your closed fist as hard as you can smack it. Not much, huh? Now open your hand and give it a little push. Not exactly scientific evidence but food for thought.
 
BatteryOaksBilly said:
Go open the door to your safe. Back off and swing at it with your closed fist as hard as you can smack it. Not much, huh? Now open your hand and give it a little push. Not exactly scientific evidence but food for thought.
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:confused:

160501113650_IMG_3800.jpg
 
My observation, when a popper falls fine all day and then takes three center hits or just rocks they're usually shooting 115s.

Some factory 147s are much softer recoiling than 115s. 124s are not really. I shot some WWB 147s I'm pretty sure were sub minor.
 
Majicmike said:
I buy 99% of all stuff in my life in cash. It's hard to find heavier stuff locally
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Isn't FG&G in your neck of the woods? The one time I was there, it looked like they carry everything under the sun. I'm just glad they're so far from me. ;)
 
Jeppo said:
Isn't FG&G in your neck of the woods? The one time I was there, it looked like they carry everything under the sun. I'm just glad they're so far from me. ;)
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Only thing I've seen is 115 in bulk. Maybe I should look again, I haven't been there but twice this week
 
Try one box of the WWB NATO and see if you don't notice the difference. $9.50 to $10 is a fair price for it.
 
115's less recoil. I found 135 JHP's to give the best accuracy in my Springfield EMP4C. The Hornady Critical Duty 135 is accurate in all my 9mm pistols. Accuracy is more important (to me) than any other variable.
 
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Here's my theory:

Power factor is a measure of momentum, mass times velocity. (p = m*v)

But energy is 1/2 times mass times velocity squared (ke = 1/2*m*v^2)

So a round with the same momentum but a lighter bullet must have more energy. Or, the opposite, a heavier bullet will have less energy for the same power factor. There's no perfect formula for "felt recoil" that I've ever heard, but it definitely is tied more to energy than momentum, since light bullets (higher energy) manifestly recoil with more snap than heavier bullets loaded to the same power factor (same momentum, lower energy).

Here's a chart with round numbers for common 9mm bullet weights and velocities, all around 125pf:

upload_2018-5-26_12-53-7.png

(Power factor computed as mass * velocity divided by a thousand. Energy computed as 1/2 mass * velocity squared divided by a million, just so the numbers are easy to compare.)

Even going from 115 to 125 is a large decrease in energy. This is anecdotally confirmed by the fact that while 115gr is virtually unheard of in competition (outside of perhaps Open, where all the rules are different), 125gr is fairly common. It is, essentially, the lightest 9mm considered realistically competitive.

Anecdotally, out of my 43 ounce Tanfoglio Stock 2, I can't tell much of a difference between 135 and 147 grain bullets. So I shoot blue 135s because I like the bullet profile.

There definitely is some diminishing returns to having energy be too low, though. Some folks dabble with 165gr bullets in 9mm, but they have never really caught on. My theory is that, past 147gr, the diminishing returns of a heavier bullet are so small (given that energy is an exponential formula) that the increased cost for negligible benefit isn't worth it.
 
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I can tell some difference between 115's and 124's...but not giant-ly so. Since I can bang off an easy 200 rds. in 90 minutes or so (alternating with other calibers and guns) I usually get the 115's since that's the cheap.
Where I personally notice the difference is with the 40 S&W. I greatly prefer the 180's over the 165's.
 
Ben B said:
Here's my theory:

Power factor is a measure of momentum, mass times velocity. (p = m*v)

But energy is 1/2 times mass times velocity squared (ke = 1/2*m*v^2)

So a round with the same momentum but a lighter bullet must have more energy. Or, the opposite, a heavier bullet will have less energy for the same power factor. There's no perfect formula for "felt recoil" that I've ever heard, but it definitely is tied more to energy than momentum, since light bullets (higher energy) manifestly recoil with more snap than heavier bullets loaded to the same power factor (same momentum, lower energy).

Here's a chart with round numbers for common 9mm bullet weights and velocities, all around 125pf:

View attachment 57529

(Power factor computed as mass * velocity divided by a thousand. Energy computed as 1/2 mass * velocity squared divided by a million, just so the numbers are easy to compare.)

Even going from 115 to 125 is a large decrease in energy. This is anecdotally confirmed by the fact that while 115gr is virtually unheard of in competition (outside of perhaps Open, where all the rules are different), 125gr is fairly common. It is, essentially, the lightest 9mm considered realistically competitive.

Anecdotally, out of my 43 ounce Tanfoglio Stock 2, I can't tell much of a difference between 135 and 147 grain bullets. So I shoot blue 135s because I like the bullet profile.

There definitely is some diminishing returns to having energy be too low, though. Some folks dabble with 165gr bullets in 9mm, but they have never really caught on. My theory is that, past 147gr, the diminishing returns of a heavier bullet are so small (given that energy is an exponential formula) that the increased cost for negligible benefit isn't worth it.
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You made my head hurt
 
Back when dinos roamed and everybody shot major..175.. I loaded some .45s all to major. But JUST to major, none to spare. I loaded 152, 180, 185, 200, 215, and 230. I took them to a match in Wilmington about 1985-6, along in there. A big match, 70 plus shooters, took all day. At the end of the day I took the top 5 finishers aside, actually 2 through 6. I won but I knew what the plan was, so I stayed out. I gave each man a mixed mag of the loaded ammo to shoot. Then we did it several more times. All, to a man, said they could not tell one round from another when loaded to 175. Again, not scientific, but food for thought. All were shooting 5 inch 1911 platforms. Because, well that's what we did 30+ years ago.
 
BatteryOaksBilly said:
Back when dinos roamed and everybody shot major..175.. I loaded some .45s all to major. But JUST to major, none to spare. I loaded 152, 180, 185, 200, 215, and 230. I took them to a match in Wilmington about 1985-6, along in there. A big match, 70 plus shooters, took all day. At the end of the day I took the top 5 finishers aside, actually 2 through 6. I won but I knew what the plan was, so I stayed out. I gave each man a mixed mag of the loaded ammo to shoot. Then we did it several more times. All, to a man, said they could not tell one round from another when loaded to 175. Again, not scientific, but food for thought. All were shooting 5 inch 1911 platforms. Because, well that's what we did 30+ years ago.
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Ya know that’s a good point. A blind test is the only way to know you aren’t imagining “felt recoil” differences.
 
Anecdotal evidence sometimes doesn't match statistics. I'm not saying that what you guys are feeling is not real, and "felt recoil" is not really something that can be measured. But here are recoil calculations from an online calculator. I'm not a pistol reloader, so I don't know if I picked a reasonable load. Hodgdon longshot powder for both loads. Recoil impulse, velocity and energy higher for the 147 grain load.

In shotguns, recoil is determined mainly by the mass of the ejecta, and powder charge and velocities have a much smaller effect.

115 1166.PNG 147 1004.PNG
 
What that does not take into account is a specific power factor that you are trying to achieve. If you take your same figures you will see that the 115s=a power factor of 132.8 while the 147s =a power factor of 147. If you loaded either one to equal the other the recoil would be roughly the same. Using your data. What the anecdotal evidence does is compare apples and apples. Beware statistical evidence, remember? Lies, Damn lies and statistics.
 
BatteryOaksBilly said:
What that does not take into account is a specific power factor that you are trying to achieve. If you take your same figures you will see that the 115s=a power factor of 132.8 while the 147s =a power factor of 147. If you loaded either one to equal the other the recoil would be roughly the same. Using your data. What the anecdotal evidence does is compare apples and apples. Beware statistical evidence, remember? Lies, Damn lies and statistics.
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Yep, if power factor is the same, recoil should be the same. For the power factors to be the same, you would apply less force to a heavier projectile versus a greater force to a lighter projectile... it's just physics...

Think of it like torqueing a bolt... if you apply 100 lbs of force on a 1 foot long wrench, you get 100 foot pounds of torque. If you apply 50 lbs of force with a 2 foot long wrench, you still get 100 ft lbs of torque.

Sent from my SM-T820 using Tapatalk
 
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BatteryOaksBilly said:
What that does not take into account is a specific power factor that you are trying to achieve.
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You'll have to school me on power factor. I don't think you can get 9mm to major power factor for USPSA easily, if that's the issue. If you're going to load 147 down to 115 power factors, then the 115 loaded similarly would have less recoil.

I had to use different powders for the 115 and 147, but "physics" calculations do not support the anecdotal evidence, or even the felt recoil responses.

115 986.PNG 147 986.PNG
 
I'm sure what the calculator I'm using doesn't take into account is faster- and slower-burning powders. I would have to bet those factors are minuscule in relation to the major recoil factors: 1) ejecta and 2) power factor, relating to speed of the load.

I realize the above chart shows two loads with vastly different power factors. Without going from minor to major, what other purpose is there in power factor? For hunting or self-defense, recoil is not a big issue like it is in practice or competition.
 
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demar, the old rules were a 175 for major. That was figured by massxvelocity. The number you decide on as the power factor is really moot. What you want to achieve to look for recoil is the same number. no matter what you decide on. Remember, we are only trying to test for felt recoil, not qualify for the match. What we found out 30+ years ago was that bullet weight had no effect if loaded to the same power factor. As to achieving major in a 9mm. Cooper did that before the 70s. His trick was to use .223 brass.
 
115 1203.PNG 147 986.PNG
My last attempt for the day. As I stated, you can school me on this. However, the major factor in recoil is the ejecta. Why would anyone want to load up 115 gain with 6 grains of powder, if it takes that to achieve the same "calculated" recoil as 147 grain going much slower? And, why would you not load the 115 grain down to a reasonable speed, for practice or competition, if the "calculated" recoil is lower?

Those power factors are not equal, but I ran out of research time. I'm not sure about the performance of 9mm 147 gr loaded below 986 fps.

I am a novice at pistols, and obviously not a reloader. You guys have much more practical knowledge than I do, and maybe more than I can acquire. That's why I am participating in this discussion, not to prove anybody wrong. My recoil training goes to my trap and sporting clays shooting, where recoil is an issue. Especially for trap when you shoot 300 max rounds in a one-day registered shoot.
 
dmarbell said:
Anecdotal evidence sometimes doesn't match statistics. I'm not saying that what you guys are feeling is not real, and "felt recoil" is not really something that can be measured. But here are recoil calculations from an online calculator. I'm not a pistol reloader, so I don't know if I picked a reasonable load. Hodgdon longshot powder for both loads. Recoil impulse, velocity and energy higher for the 147 grain load.

In shotguns, recoil is determined mainly by the mass of the ejecta, and powder charge and velocities have a much smaller effect.

View attachment 57640 View attachment 57641
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So they are pretty much the same in felt recoil
 
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For most of us, who don't reload, these would be obvious choices:

Blazer CCI 9mm 147 gr 985 fps, power factor = 144.79
Blazer CCI 9mm 115 gr 1125 fps, power factor = 129.38

Recoil would have to be lower on the 115 grain.

147 gr with power factor of 130 is 900 fps. Why not load 115 gr at 900-1000 fps and get the lower recoil?
 
dmarbell said:
For most of us, who don't reload, these would be obvious choices:

Blazer CCI 9mm 147 gr 985 fps, power factor = 144.79
Blazer CCI 9mm 115 gr 1125 fps, power factor = 129.38

Recoil would have to be lower on the 115 grain.

147 gr with power factor of 130 is 900 fps. Why not load 115 gr at 900-1000 fps and get the lower recoil?
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Because that wouldn't make power factor. 125pf is the floor, most folks go for 130ish to be safe.

Pretty sure 115gr at 900 wouldn't run most guns anyways.
 
FlatFender said:
Pretty sure 115gr at 900 wouldn't run most guns anyways.
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I found a 147 gr load, 4 gr powder, 883 fps. Power factor 129.80. Would that load cycle most slides?

It takes 5 gr at 1127 fps to reach power factor 129.60 for 115 grain. "Calculated" recoil is almost identical, slightly lower for the 147 gr. But I'd bet the muzzle blast and felt recoil would be lower with the heavier bullet going that slow. If it would cycle the slide.

I shoot factory 9mm 115 gr that ranges around 136-138 power factor. That's 940 fps for 147 gr. I guess I'm going to pull my dad's reloading stuff out and load some 147 grain to that speed and see for myself. He's probably too feeble to help me, other than to supervise but he used to load pistol and rifle loads.
 
@dmarbell,,, I picking up some 125 and 147 ammo today. It suppose to be loaded as side shooting. Next time I go to the range your welcome to go with me to do blind test. That way we can see if there any true felt recoil difference. Ive been wondering myself
 
Thanks, all, for the information. I learned tons about shotgun loads from a couple of shotgun forums. I thought I knew something about shotguns and shells until I jumped into discussions with some folks who had 100,000+ rounds of registered trap under their belts. That's why I join these discussions about pistol shooting, so I can learn from all you more experienced shooters. Sometimes I can be hardheaded, but I want to be schooled - so help me out.

I'm shopping for minor power factor 147 grain bullets now!
 
dmarbell said:
I found a 147 gr load, 4 gr powder, 883 fps. Power factor 129.80. Would that load cycle most slides?

It takes 5 gr at 1127 fps to reach power factor 129.60 for 115 grain. "Calculated" recoil is almost identical, slightly lower for the 147 gr. But I'd bet the muzzle blast and felt recoil would be lower with the heavier bullet going that slow. If it would cycle the slide.

I shoot factory 9mm 115 gr that ranges around 136-138 power factor. That's 940 fps for 147 gr. I guess I'm going to pull my dad's reloading stuff out and load some 147 grain to that speed and see for myself. He's probably too feeble to help me, other than to supervise but he used to load pistol and rifle loads.
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Probably cycle. Most USPSA loads do, most competitors shooting minor load to about 130PF, some lower, some higher. I bet half if not more of those loading their own minor power factor ammo are using a 147 of some flavor.

With a coated 147 3.2gr of Titegroup runs 905 (133PF) out of my G17 reliable as the sunrise. 3.0 of Bullseye is right around 890 (131PF).

2.7gr of Red Dot and a 155gr cast runs about 825fps (128PF), also reliable, it is very soft, but noticeably slow cycling. 2.4 doesn't make PF but is honestly 22LR like in feel, still cycles sometimes doesn't catch the slide lock.

ETA: Before she fixed her grip my wife could limp wrist those 147 loads and induce all manner of malfunction when the guns had factory recoil springs. With a 13lb or 11lb spring it doesn't matter.
 
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