Federal 9mm ammo puzzlement

[DENALI]

Hi there I also post on the CZ-Forum and posed the following question pertaining to federal's published ballistic's. Please keep in mind that while a shooter of 35+ years I don't reload my own. I'm very curious about these loads all Federal manufacture. 9mm P9HS31 124 gr=1150fps, 9mm P9HST3 124gr +P=1200fps, and last but not least 9mm P9HS3G1 124gr +P+=1170fps..Now I understand that the +P+ designation is outside of SAMMI specs and as such there can be some varience, none the less is this nothing more than some marketing slight of hand and therefore an oversight and a mistake? I mean there's a 30fps difference between the two +p loads with the slower bullet actually designated as the +P+! What am I missing here...Thanks guy's.............................::::

 

[sig226]

+p+ designates pressure, not velocity. It's a NATO load, which is the kind of stuff that snapped the slides on the original Beretta pistols. It may be that the powder didn't burn completely in the test barrel with the +p+ loads.

 

[DENALI]

Hey there Sig226, what I'm most curious about is this, what benefit is derived by loading the exact same bullet, lets say 124 gr hydra-shock's. What is gained by loading one to 1200fps and calling it +P and the other identical 124gr bullet to 1170fps and calling it +P+, what benefit is realised by an additional amount of pressure at no increase in velocity and then claiming or at least implying increased power?

 

[Mainsail]

That’s an interesting question! Well, I’m going to throw my guess in that it has something to do with the type of powder with which it’s loaded. IOW, some powders burn slower than others, so in the (short) test barrel it didn’t get to burn completely, thus a lower velocity.

Total guess though.

 

[DENALI]

Hey there Mainsail, maybe thats it but I just don't know. Thanks for taking a shot at it though. Maybe we'll get some further comment's from the gallery as the holiday winds down.......

 

[sig226]

IMO, the difference is the barrel used to test it. The +p+ ammunition is intended for a submachine gun with a barrel of eight inches or more. When the cartridge is fired, the powder burns for a specific time, depending on the powder and the load. Handgun rounds are designed to give a very short burn because the barrels are typically five inches or less in length. But the submachine gun barrels are longer and intended for higher pressures. A slower burning powder can be used because it will take longer for the bullet to leave the longer barrel, therefore there is more time for the powder to burn.

So if you put the hot stuff in a short barrel, you get less performance.

 

[DENALI]

I can't agree with that as Winchester states on the back of the box of there RA9TA 127gr +P+ that it is only for use in pistol's. Further they insist that it's not for use in Uzi firearms! I don't see the same warning from Federal on there package.

 

[Pumpkinheaver]

I would guess the velocity for the +p+load is a typo if it is in their published balistics instead of a true chrono reading.

 

[DENALI]

Hi there, it is no mistake. Federal markets the P9HS3G1 as +P+ and LE only. This is what has sparked my curiousity. The load is a tactical one which I take to mean developed to contend with barriers. There are other interesting examples, for instance the Remmington GS9MMD is a 124gr 9mm +P at 1180fps, a slight obvious increase in velocity over the +P+ federal load. Now if +P+ is actually the Ne plus Ultra of 9mm then what's going on at Federal ? My understanding is these loads are restricted to LE only and indeed the boxes are marked accordingly, keeping that in mind the next question becomes why ? All loads have been described by there manufacture's as having been chronographed out of 4-inch barrels. Speer loads the 124 gr Gold Dot to 1150fps and sells it as a standard load. What happens in those additional 20fps that leads Federal to restrict the load ? I'm very very curious about this and hope I'm making sense to you guy's......Keep in mind that all my life I've just been a shooter and have never loaded or reloaded ammo...........

 

[sig226]

This I have to see. Pretty much every handgun manufacturer in the world tells you not to use +p+ ammunition. The reason is that there is no pressure standard for it. SAAMI (Sporting Arms and Ammunition Manufacturer's Institute) sets safe chamber pressures for firearm cartridges. The SAAMI pressure limit for the 9mm is 35,000 psi. +P ammunition exceeds this pressure by ten per cent, so SAAMI pressure specification for the +p load is 38,500 psi. There is no standard for +p+ ammunition chamber pressure. It's more than +p. That's what that means. It's the NATO load that broke the slides on the Beretta 92 F pistols.

Here is SAAMI's take on how +p+ ammunition should be used in handguns:
In firearms chambered for:
9mm Luger (Parabellum)

Do not use these cartridges:
9mm NATO (Military)

All loads have been described by there manufacture's as having been chronographed out of 4-inch barrels.

This is what I wrote. In order to get the velocity advantage from the +p+ loads, you need the longer barrel. Anything you see when you fire a gun is wasted powder and wasted energy. When you got that bright flash, all you did was heat up the range. It didn't use that energy to accellerate the bullet because the bullet left the barrel before the powder was completely burned.

Put mathematically: A 9mm bullet travels at 1200 fps in a four inch barrel. It travels 4 inches, 1/3 of a foot, in 1/3600 of one second. The distance is twice as long in an 8 inch barrel. It takes 2/3600 of a second for it to get out. That means the burning powder has more time to act on the bullet, and that makes it go faster.

The sale of +p+ ammunition is not restricted by law, although the manufacturers probably try to control the sale of it because they know what it can do to firearms in poor condition. You can get the stuff all over the web, though, and some FFL's will order it for you. Others won't because they're afraid of a lawsuit if someone puts it in an old gun and it blows up.

 

[DENALI]

You have me somewhat confused, winchester states unequivoclly that there 127gr +P+ load is for use in pistols but not Uzi firearms, an obvious reference to sub-guns. To confirm this to your satisfaction just google RA9TA and read the factory info. As to being able to aquire any particular load over the net thats not the point. The point is the factory WANTS to restrict the load for whatever reason they feel appropriate. I mention the barrel length's only because the factory's have posted it and therefore it's available data that contrdicts the longer barrel explanation posited by yourself. As to the designation +P+ my understanding is that it simply exceeds industry standards and obviously should be used only in comparable firearms. Regardless, Federals claim of +P+ in this instance is not supported by the available data (there own and others easily avaiable) and as such appears misleading regardless of intent...............

 

[sig226]

Not all machine guns are Uzis. If they wanted to restrict it from sub guns, they would say that. I have no idea why it has a problem in the Uzi. The Winchester 9mm load you gave is +p. The +p+ load is the NATO loading, which produces the same results with the four inch barrel as Federal.

Winchester 9mm NATO

Note that in a four inch barrel, it is significantly slower than the Ranger +p load you noted. Have you ever looked at load information that mentioned losing x number of feet per second for every inch you shorten the barrel? This is what's happening here. If you put the +p+ load in a longer barrel, the powder will burn for more time and it will exert more pressure on the bullet than the +p load. The +p+ round needs a longer barrel to generate the velocity, but it will develop a higher velocity than the +p load in the longer barrel.

Changing bullet speed involves more than just putting more powder in the case. The study of it is called interior ballictics. Lots of hobbyists are pretty good at exterior ballixtics, which explains what happens after the bullet leaves the barrel. Interior ballistics, what happens in between when the primer fires and the bullet leaves the barrel, is downright arcane.

They use different powders for different applications. The powders burn at different rates. This is controlled by the shape of the powder granules and by adding chemicals to it to slow down the burn. The amount of powder in the case also affects pressure. If you put insufficient powder in a case, it can actually explode when it is fired. All kinds of interesting things can happen, which makes it as much an art as a science.

But I assure that what's happening is that the powder in the +p+, or NATO load, does not have enough time to burn and produce its full speed. if it is fired in a longer barrel, it will produce more speed than the +p fired out of the same barrel.

Here's a page that shows the burn rates of various gun powder formulations, and explains a few things about them.

 

[DENALI]

I"m not sure but perhaps you're correct to some extent in regards to the Federal tactical load, the only alternative that I can envision is they're fudging the ballistics. As to why I can only guess. Regarding Winchester's RA9TA, the load is a 127gr +P+ SXT hollowpoint and as such it is clearly marked that way on both the box and the cartridge, further there RA9115HP+ is also marked as +P+ on both box and cartridge( an interesting aside, the USA9JHP is identical to the latter but loaded to 1225fps and 383fpe) and both are claimed by Winchester to be in the vicinity of 40,000 cup...............P.S. 124gr NATO is to my understanding running at about 39,000 to 42,000psi, the latter is the max load and to my mind hotter than any American +P or +P+...............

 

[coosbaycreep]

I'm clueless on the other stuff, but as far as the warnings about not using them in an uzi, I read over on uzitalk (I think) one time that the firing pin hits so hard in uzis that it will sometimes pierce the primer (I think it's called a slam fire or something) on regular ammo, so they usually shoot ammo with harder primers.