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hey everyone,

I see so many different varieties of ammo that one can choose, I am wondering what some of the things mean, such as the different numbers such as 155gr., 180gr. etc..

Do these nubers signify the strength of the charge? Could someone please explain, as well as explain how you make your choice for which ones to use?

I have an XD-40 sub compact..thanks!
 

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155 gr. = 155 grains, the weight of the bullet.


FMJ = full metal jacket, a lead bullet with a copper jakcet. good target load, usually cheaper


HP = hollow point, a bullet with a hole in the center, they expand on impact. good for self defence, usually more expencive
 

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Discussion Starter #3
wJAKE19 said:
155 gr. = 155 grains, the weight of the bullet.


FMJ = full metal jacket, a lead bullet with a copper jakcet.


HP = hollow point, a bullet with a hole in the center, they expand on impact.
thanks Jake, by weight do you mean the weight of the actual bullet part? So these numbers do not have anything to do with the charge itself?

Also still wondering what makes someone choose the different weights. Is a heavier weight bullet just more lead, to do more damage?
 

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is the 155 grains as in how heavy the slug is, or how much powder is in the cartridge? thats why 180 goes faster then 165?
 

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the number 155 or 165 or 180 is the weight of the slug, not powder.

normally the smaller the slug, the faster it will go. another rule of thumb is a lighter bullet will have a lesser recoil. there are exceptions to every rule, but this is how it works most of the time.

you can decide what bullet you want to shoot just by preference, get out there buy a bunch of different bullets shoot em up and decide what you like best.
 

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I have a 9SC and have run the full gamit for loads 95g-147g and did some informal tests on each and found that the 124g starfire did the best for penatration and frag but this is just me
 

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what did you use as a media to test penitration? I would like to do some tests myself but I dont feel like buying a side of beef for shooting at.

I guess I could go shoot my neighbors pigs... naaa, I better not.
 

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A cartridge, which is what we're talking about here, consists of the various parts, which when combined together, make the actual cartridge.

First, there is the case of the cartridge, which basically holds it all together, and is the part expelled from the chamber upon firing. The case has a primer in the base, which is the sparkplug that fires the gunpowder inside the case.

Gunpowder does not explode, but instead burns very rapidly and produces gases from the rapid burning. As the gases expand, they produce pressure on the base of the case, as well as the walls of the case, and the base of the bullet. Since the case is confined within the chamber, and can only expand as far as the chamber will allow, the pressure has to go somewhere. That somewhere is by pushing the bullet from the case, since that's the only way to alleviate all that excess gas, and pushing the bullet all the way out the barrel.

The bullet itself, is the projectile, or the hunk of material we are trying to make go downrange rapidly.

Bullets come in various materials and coatings. There are bullets made from a mix of lead, tin and antimony, which are usually referred to as "cast bullets", but can also be formed by swaging. Swaging is the process of placing great pressure on an object and forming it into a mold. These bullets require some form of lubrication to keep them from coating the bore of the barrel with lead.

Another type of bullet is formed by making a lead core in the shape desired, and then coating it through electrolysis with copper. These are referred to as "plated bullets". These bullets will be fully encapsulated by the copper jacket, with no lead exposed. They are generally formed from pure lead, but are able to be driven through the barrel without any lubrication. Velocities of plated bullets are recommended to be kept at 1,200 fps or below.

A third type of bullet is referred to as "full metal jacket", which is usually a thicker jacket than a plated one, and is formed by swaging a lead core into a copper jacket. These bullets will have lead exposed at the base, but the nose of the bullet will be the metal jacket.

A fourth type of bullet is what is normally referred to as either a "jacketed hollow point" or a "soft point" bullet. The jacketed hollow point is formed in a copper jacket, with the open portion facing forward, and the final step is a die which makes a hole down into the center of the bullet, facing forward. This helps the bullet to expand by allowing hydraulic pressure to get into the cavity and push the lead core in an outward direction. Without moisture, there can be no hydraulic pressure, but some bullets will expand in dry material from the forward momentum and contact with a hard medium, which overpowers the structural integrity of the lead material the bullet is constructed from. A soft point bullet is formed the same way, but instead of a hole being punched into the lead core, it is formed into a solid point, which can be either flat or rounded, depending on the purpose of the bullet.

There are other types, but these are the basic designs and construction.

When people refer to a cartridge of a given caliber as a number, other than caliber, it refers to the weight of the actual projectile, or the portion you intend to send towards the target. The case, primer and powder don't figure into this number, only the actual bullet. Bullets in this country are weighed in grains. There are 437.5 grains to the ounce, or 7000 grains to the pound. So when someone refers to a 9mm bullet as 124 or 115, they are talking about the weight of the projectile, in grains. This may, or may not, refer to the "power" of the bullet, since there are various power levels cartridges can be loaded to.

Other numbers will refer to the caliber, which can be very confusing, since there are several different methods used for this around the world. In the XD pistols, all you have to worry about is 9mm, 357 Sig, .40 S&W and .45 GAP.

The 9mm refers to the 9x19 cartridge, also known as the 9mm Luger, 9mm Parabellum or just plain 9. The bullet is .355" in diameter, or 9mm, and the case is 19mm long, hence the 9x19 designation.

The 357 Sig, and there is no period before the 357, is solely a name for a cartridge, and has nothing to do with the size of it. The bullet is 9mm, or .355" in diameter. It was designed to compete with the .357 Magnum revolver cartridge in the 125 grain loading, so the catchy name of 357 Sig was coined, because it was the Swiss firm of Sig who developed it. This case resembles the .40 S&W case necked down to 9mm, but in reality is a case that was designed from the ground up to handle the pressures of this high pressure round. The base and web area, directly above the base, are made thicker than the .40 S&W round, again due to the higher internal pressures of this great cartridge.

The .40 S&W, which stands for Smith & Wesson, the company that pioneered the round, is a 10mm Auto case, which has been shortened to fit in the 9mm framed pistols, and shoots a bullet .400" in diameter, or 10mm. It also uses a small pistol primer, whereas the 10mm uses a large pistol primer. This was done primarily as a law enforcement round, in answer to a demand from the Federal Bureau of Investigation (FBI), for a round that would deliver better ballistics than the 9mm, but not the recoil and grip size of the 10mm pistols.

The .45 GAP, which stands for Glock Auto Pistol, is also a shortened case from the .45 Automatic Colt Pistol (ACP) cartridge, which would fit into a smaller grip frame, but deliver similar ballistics as the .45 ACP. Both .45's shoot a bullet that is .452" in diameter.

This is a very simplistic explanation of what a cartridge is, but should give new shooters an idea of some of the terminology used.

A good medium for testing expanding bullets is phone books that have been soaked overnight in a bucket of water. Newspapers will also serve this purpose, but they have to soak up enough moisture to assimilate tissue, as far as moisture is concerned. If the phone books or newspaper are dry, all you'll get is deformed bullets, with no indication how well they will expand in tissue. If you decide to use this, make sure you have at least 24" of material to shoot into, and a safe backdrop. Depending on the density of the material, some bullets will travel a long way before coming to a stop, so use great caution when testing them. Bullets will also sometimes change direction in test medium, so again, use great caution, especially with full metal jacketed (FMJ) bullets.

Hope this helps.

Fred
 

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