Defensive Carry banner

115, 124, 148 +p and +p+

4K views 9 replies 9 participants last post by  Madcap_Magician 
#1 ·
I am new to guns and trying to learn as I go. I think I understand but want to ask for more knowledge. The 115, 124, and 148 are the weight of the bullet in grains. What is the reason for the different weights. What is the +p and +p+ I know it deals with the pressure generated by the gunpowder charge but again why do we need +p and +p+. Sorry for the weird questions but I dont have anyone local to ask.

I am using a 9mm Px4 full size F model if you need that info.

Also if I can find any ammo, can I use the Tulammo steel cased stuff or will that be bad for my pistol.
 
#2 ·
Len, I have basically the same questions and no one local to ask, also. Plus, why is FMJ considered a target round? What is the difference between it and whatever else is available.
 
#3 ·
I am new to guns and trying to learn as I go. I think I understand but want to ask for more knowledge. The 115, 124, and 148 are the weight of the bullet in grains. What is the reason for the different weights. What is the +p and +p+ I know it deals with the pressure generated by the gunpowder charge but again why do we need +p and +p+.
Different weights and grains of powder charge result in different performance characteristics. Raise the pressure, and you'll generally push the bullet faster, assuming the added pressure can be utilized in the given barrel's length to do the work. Reduce the weight of the bullet being pushed by a given level of pressure, and you get a faster bullet.

Some want different performance for short-bbl guns; others for self-defense; others for target/accuracy purposes. Most just want to avoid 3ft of muzzle blast, unspent powder, unneeded kick. And the manufacturers and reloaders are open to try the path they see fit, for best matching a given gun/purpose. Every gun (and everyone) is different. Hence the choices.

Whether something's good, bad or fine on a given gun depends on the gun. Accuracy-wise, I'm of the opinion that the better loads for a given gun match the gun's balance, length of barrel, and how the gun shoots in the hand. I've had pistols with 4-5" barrels where the balance was so exceptional with 124gr or 115gr hot "range" loads that that's practically all I shot through them. I've had other pistols with sub-4" barrels where the balance and accuracy worked best with 124gr +P or +P+. And still others with ~3" barrels (or shorter) where a good short-bbl defensive load in 115-124gr worked best.

So. Depends on your needs. Depends on what you find works most reliably in your specific gun, as there often are differences from gun to gun that'll mean a given brand/type of ammo that works perfectly in a buddy's gun might be unreliable in yours, despite being the same make/model of gun.

Any decent defensive JHP 124gr load ought to work fine in that gun, assuming you find it to be reliable in yours.

Any decent "range" round in FMJ in any weight ought to work fine in that gun, too, again assuming reliability.

And given the crappy market conditions for availability over the counter, you might need to take anything you can get. Or, buy online and have it shipped.
 
#4 ·
In things pertaining to ammunition, weight is measured in a unit called grains. 1 grain is equal to 1/7000th of a pound.

Bullets come in all kinds of different weights because they usually offer different terminal results, one might be more accurate than the other in a particular gun or a certain velocity window is met by one weight of bullet when using a full power load, but not the others. An example of this is 147gr (not 148) sub-sonic ammo. It will not produce a sonic crack and is a good option for use in a suppressed weapon. A heavier bullet will also have more inertia and can penetrate deeper than a light weight (115gr) bullet. I believe bullet design is more of a factor in terminal performance than bullet weight (within reason).

The reason heavier bullets are slower is because more force is required to move that bullet out of the case and down the rifling in the barrel. You can't just put more powder behind that bullet because the added length of the heavier bullet takes up space in the case that could otherwise be used for powder. Another thing that limits velocities with any bullet weight are chamber pressures. More powder will usually mean higher velocities, but when chamber pressures exceed safe levels bad things happen, so chamber pressure is another thing that limits the velocities that bullets can be driven to.

+P means the chamber pressures of that load are higher than the maximum pressure of a standard load. For 9mm, a +P load might be up to 10% higher pressure than a non +P load.
The normal maximum chamber pressure for a standard 9mm load is 35,000 PSI. For a +P load, it is 38,500 PSI. It is this pressure that pushes the bullet down the barrel.

Target rounds are usually FMJ because full metal jacketed bullets are cheaper to make than a jacketed hollow point bullet. FMJs will not cause any feeding issues that might occur with older guns as well because there is no cavity at the front of the bullet going over the feed ramp.

For self defense, carry a quality jacketed hollow point round. A quality expanding bullet increases the size of a wound channel and because frontal surface area is increased, the bullet is limited to how deep it will penetrate. For 9mm, a quality expanding JHP bullet will likely penetrate 10-16" in flesh simulation. FMJs do not expand. They will produce a narrow wound channel and cause excessive penetration (20"+).

Edited: +P can be seen as advantageous because the added pressure increases the downrange velocity of the bullet compared to a standard load. A +P load delivering a 147gr bullet at 1050 feet per second will deliver more energy to your target than a standard load sending a 147gr bullet at 1000 feet per second. The disadvantages could include increased recoil and (insignificantly) increased wear on your firearm. Because +P ammo is generally only defensive ammo, there probably aren't going to be a whole lot of +P rounds going through your gun. As long as you use +P ammo modestly, you should not be overly concerned about it. Most modern handguns are designed to shoot +P ammunition without any problems. Your owner's manual should say what kind of ammo is okay to use. Manuals for most modern 9mm handguns will say +P is okay but rarely do manufacturers say +P+ is allowable. Ruger is one manufacturer that says limited use of +P+ is okay to use in their 9mm pistols with the exception of their LC9.

Really, you could learn a lot more than this with a simple Google search... 9×19mm Parabellum - Wikipedia, the free encyclopedia
 
#6 ·
This^^^ and one other reason to use fmj for target practice is the risk for over penetration. You dont want one going through the bad guy and hiting an innocent bystander. For defence i use something in the 115 to 124 gr jhp loads in my 2 9mms with 3 and 3.5 inch barrels.
 
#5 · (Edited)
Note: It is important to understand the terms being thrown about. The "P" in +P stands for pressure and as noted above, is by industry specification set at no more than 10% greater than standard. +P+ on the other hand, has no industry standard and if you fire such loads in spite of what some manufacturers may say, there is no telling what you may be shooting or whether your pistol will tolerate it because they, and you, have no way of knowing the pressures involved.

As for Full Metal Jacket or FMJ bullets, they are not considered target rounds. A proper target bullet is designed for accuracy and to cut sharply defined holes in a target. Note also that a target round also has finer tolerances of case dimensions and powder type as well as closer tolerances of the bullet itself.

FMJ bullets are used for practice not because they are target rounds, but solely because they are cheaper than the fancy hollow points designed for self-defense, thereby allowing more practice for any given cost. They are cheaper because they are easier to make, used by military throughout the world, and thus are produced in vast quantities which helps to lower the cost due to bulk production.
 
#7 ·
Thanks to all who responded so far. I don't know about the OP, but I have learned a lot. Keep 'em coming.
 
#8 ·
The +P+ ammunition needs a longer barrel length to burn the power charge in the cartridge. LEOs use it in the MP5s as they have an 8" barrel and can use all the velocity and energy. In a barrel under 4.5" it is a waste on money! In My CX4 Storm I use it to get the most out of a 9mm! But it has a 16" barrel!

JMHO I would stick with a self defense round like +P Speer gold dot. As for FMJ I purchase low cost ammunition for range time. Of course if you can find any low cost ammunition today, your a lucky person!
 
#9 ·
Also muzzle flash can be a factor depending on which brand of bullet, bullet weight, and which gun it is shot from. Cor-Bon 115GR +P in my G-19 has very little to almost no muzzle flash. Winchester Ranger T 127GR +P+ has no muzzle flash in my G-19. My reloads in 124GR Gold Dot HP's has muzzle flash using either AA-2 or Unique powder behind it. These bullets were tested in my membership range where you can control the lighting and I had someone else do the shooting so I could see the results right next to the gun. The folks who make the "Social Ammo" go to great lengths to get performance up and muzzle flash down. YMMV. BTW +P+ in 9MM is near +18% over standard loading and outside of SAMMI specs.
 
#10 ·
115-gr., 124-gr., and 147-gr. are all common 9mm bullet weights. The heavier bullets give up velocity but tend to penetrate deeper due to their increased weight. The weights are different because different people seek different performance profiles in different calibers.

148-gr. is a common .38 Special bullet weight for wadcutters, which are a type of flat-ended bullet generally used for targets because of the neat, round holes it punches in paper.

As a matter of weight, the ratio of pounds to grains is 1/7000.

+P ammo is ammo that is pressure tested up to 10% over SAAMI-specified max pressure for a given caliber. SAAMI is kind of the standards board for ammunition-related technical specifications. +P+ is ammo that is loaded beyond recognized pressure limits for the caliber. SAAMI does not have maximum pressure ranges for +P+.

If your Px4 will feed steel-case, it will not harm your pistol.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top