9mm std vs +P

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Does anyone know if there is a real difference between standard velocity and +P 9mm ammo in a 3" barreled semi auto?

Assuming you're talking about self defense purposes, +P may give a slight advantage in gel, but I doubt there would be much of a difference in the real world. My preferred SD 9mm load is standard pressure 147gr HST and I wouldn't hesitate to use it in a short-barrel gun.
 
A 3" auto drops off fps very fast from a 4 or 5" barrel.

It is almost impossible to get a +P speed out of a 3", even with reloads.
You also need a load that you can handle and shoot well, if possible.

I could reach +P in my 3.5" C9 but in a Kahr 3" I could only get
a 115 ball to 1168fps and a 124 ball up to 1118fps

I never got to test the 147 HST in this 3" pistol but it might be my choice
with the heavier bullet, that is slow any way.

Even with +P ammo, you will be actually shooting a "Standard" load......
out of a 3" barrel, from what I have learned in my test.

Good shooting.
 
is +P considered the fps or the pressure it generates?

I always assumed pressure, the fps was expected but generally fell off the shorter the barrel - all depending on powder burn...
 
+P refers to the pressure of the loading. Read the SAAMI page for more info on what the designations mean.


As to the OP's Q: that will depend on the individual gun and the individual load. While it is difficult to figure out what's an apples-to-apples comparison, I have found there's not always much difference between the velocities delivered by very similar loadings (same bullet, same maker) of standard or +P designation.



For instance, out of my 3" SIG-Sauer P938 (Range at 5950’ > sea level, c. 73°F, c. 45% humidity), Remington's standard pressure 124-gr Golden Saber BJHP did 1056 fps/61.29 spread/23.28 deviation



and the +P variant with the same bullet did 1114/20.02/12.76. In that little, light gun, I'm carrying the standard pressure variant.
 
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is +P considered the fps or the pressure it generates?

I always assumed pressure, the fps was expected but generally fell off the shorter the barrel - all depending on powder burn...
You are correct, the P in +P does stand for the word Pressure

Everything else being equal, more pressure will give you more velocity

The SAAMI +P designation indicates that this round of ammunition is loaded above industry standards

So if you have two identical rounds from the same manufacturer one being standard pressure and one being +P, the +P round will always leave the handgun barrel faster than the standard pressure round.

It does not matter what handgun we are talking about

The question should be, is the gain received worth the extra wear and tear that a +P round imparts on the firearm over a standard pressure round of ammunition

In my teeny, tiny polymer framed 9MM pocket pistol, I always carry standard pressure ammunition. If I am carrying a slightly large metal framed pocket or personal pistol I will usually carry the +P offering
 
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Nowadays...

Nowadays +P is only a marginal improvement over a good standard load by the most common manufacturers.

But, the manufacturer should specify whether a particular gun is suitable for +P. Many small 9mms are standard only. If your gun is suitable for +P, it's a matter of preference. Yourdefense ammo like Federal HSTs, Speer Gold Dots, Remington Golden Sabers and the like all perform well with a standard load. If you can get a little more velocity with a +P and you can handle the recoil and the extra expense, go ahead.

PS: Speer makes special 'short barrel' ammo for short barrels that are designed to expand at lower velocities. It's good stuff, but so are the others that I mentioned.
 
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ContinentalOp hit it right on the head. I carried a BHP for over 40 years and the 147gr. standard is a great load. Totally adequate. The difference between standard and +P is mostly negative--greater recoil, noise, muzzle blast, and more difficulty getting on target for the follow up shots. Any type of shooting outcome is 100% dependent on proper placement of the shot onto the target.
 
Try several ammos and bullet weights/styles, +P and standard pressure. Use what does best for you in your gun; the pressure designation matters not.

+P, the latest bullet style, etc. is more gun article, gunfighting theory, and Internet forum-oriented than something really useful. Hitting what you aim at consistently is far more important than all the other.
 
Thanks all.
I asked because my favorite lawyer (I tell him that's an oxymoron) says it's easier to defend me successfully if I shoot an auto instead of the revolvers I usually carry, mostly because I've tuned the actions. I just bought a Sig P365 with 10 and 12 round mags that is +p rated and if it shoots well and consistently the Js will probably end up in the safe. Doesn't seem to me that +P is worth the muzzle flash and it seems you all agree. Only have 75 rounds thru it but without any issues. I'll go for 400 before I carry it. Thanks again.
Joe
 
If you believe the stats at Ballistics by the Inch, +P loads will give you a 100 foot pounds of energy advantage and as much as 250 higher muzzle velocity from a 3 inch barrel as opposed to standard pressure rounds.

If you believe Lucky Gunner results, the Federal HST 124 grain standard pressure and the +P round have the same velocity and energy from a 3.5” barrel, with the penetration advantage median depth going to the standard pressure round.
 
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Try several ammos and bullet weights/styles, +P and standard pressure. Use what does best for you in your gun; the pressure designation matters not.

+P, the latest bullet style, etc. is more gun article, gunfighting theory, and Internet forum-oriented than something really useful. Hitting what you aim at consistently is far more important than all the other.

An excellent summary, in addition to adding "100% reliable feeding and function". Fast accurate hits are the key...

For the record, 9 mm standard SAAMI pressure is 35000, and +P 38500 psi. Whether ammo is loaded to full spec for either category is often an open question.
 
I wonder why a 12 round auto would be "easier to defend" than a 5 round revolver in a trial. I wonder if the handgun of choice has ever been the subject of analysis in a trial where use of a handgun was found justifiable.

I know that Bernie Getz was considered to be legally justified ....not guilty of attempted murder, assault, etc. ....in shooting 4 men with his 5-shot revolver. Of course, he got prison time for illegal possession of a firearm that a jury decided he had not used incorrectly.

I guess if the world made sense, cowboys would ride side-saddle.
 
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Has to do with the prosecutor trying to prove the gun was fired negligently because it was modified and could be fired single action (hair trigger).
 
I wonder why a 12 round auto would be "easier to defend" than a 5 round revolver in a trial. I wonder if the handgun of choice has ever been the subject of analysis in a trial where use of a handgun was found justifiable.

I know that Bernie Getz was considered to be legally justified ....not guilty of attempted murder, assault, etc. ....in shooting 4 men with his 5-shot revolver. Of course, he got prison time for illegal possession of a firearm that a jury decided he had not used incorrectly.

I guess if the world made sense, cowboys would ride side-saddle.


Again, getting into conjectural gunfighting theory; pretty much a wasted effort, but a subject some obsess over. No two situations are the same.
 
To help answer the OP's question, no. If you have a 3" barrel 9mm then the difference with +P over standard pressure will be negligible. There is a certain threshold in barrel lengths when 9mm gets to a certain velocity when a HP performs as it was designed. Paul Harrell on his YouTube channel has clearly demonstrated there is a huge difference in FPS between a 3", 3.5" and a 4.9" 9mm barrel using the same bullet. A difference of like 90fps more in a 3.5" barrel over a 3" barrel. That is a BIG difference.

he mentions that in the middle of this video

[ame]https://www.youtube.com/watch?v=0rPTk8raXdo[/ame]
 
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My standard 9mm competition load is 124gr FMJ over 4 gr Titegroup.
It chromos PF 120 in my Shield, PF128 in my 4 1/4" M&P and PF 133 in my 5" M&P. Notice that does not follow any of the "General Rules."
Until you chrono the loads of interest in YOUR gun, you don't know squat....no matter how much fun it is to guess.
 
I like 147 gr bullets in my P938. It's pleasant to shoot.
 
With modern bullets, I have become a fan of the 147 grain JHP in 9x19mm. I've tried standard pressure and +P loads in a S&W 6946, S&W 439, and a TZ-75 Series 88. There is definitely more recoil and muzzle flash with the +P loads and based on ballistics gel results published by Federal, Winchester, and others such as TNOutdoors9, I don't think the +P has much, if any, advantage over standard pressure loads. For me, the extra recoil, which means accelerated wear on the firearm, and flash in a compact pistol is not worth a tiny gain in velocity. For years I have carried the Winchester Ranger 147gr T-Series JHP load, I expect to soon transition to the Federal 147gr HST load, both standard pressure.
 
Has to do with the prosecutor trying to prove the gun was fired negligently because it was modified and could be fired single action (hair trigger).
You need to find another attorney. That one clearly doesn't have a clue about shooting cases.
What this "attorney" is saying is you use your firearm in a self defense situation and the prosecutor is going to argue that you did not intend to shoot the person, it was an accident because your firearm had a light trigger. That makes absolutely no sense. No prosecutor is going to argue an accidental shooting if you're saying you were in fear of your life and the use of deadly force was justified. Find another attorney.
The question is did you intentionally shoot the person. Trigger pull weight has nothing to do with it. If you did not intend to shoot the person then it doesn't matter trigger pull either. The question in shooting cases is would a reasonable person believe they were in fear of their life or great bodily harm where the use of deadly force is justified.
If you say you didn't intend to shoot the person then trigger weight won't matter either. At trial it's either you were justified using deadly force or you weren't.
 
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