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Discussion in 'Handguns: Autoloaders' started by rogerjames, Oct 26, 2006.

  1. rogerjames

    rogerjames member

    Sep 21, 2006
    I don't want this to be a big load/bitch load/best deffense load thread, I truly do not underdstand the differences between the semi-auto loads. I own a Ruger SP-101, I understand the ammo for this revolver, .38, .38+P, .357, grain weight etc. I also understand the differences in recoil, price, etc. Been looking to add semi-auto in near future but am confused about semi-auto ammo (speed, recoil, cost, availability, etc). I understand the whole 9mm, width of the bullett stuff, but when we start talking 357sig, 40SW, 45AP, 45Glock, 10mm, I get confused as to their differences.
  2. ceetee

    ceetee Participating Member

    Sep 7, 2003
    There are several types of 9mm. They're named based on case length (in millimeters). 9x17, 9x18, 9x19, and so on. They also have Imperial names: .380 ACP, 9mm Makarov, 9mm Parabellum. MOst times, if you hear someone talking about a generic "9mm", they're talking "Parabellum".

    A step up in power and recoil is .40 S&W. While some people find it harder to shoot, the advantages are that it's more powerful, and you can fit nearly as many rounds into a gun chambered for .40 as you can for a similar gun in 9mm.

    A .357 Sig is just a .40 S&W case, with the neck downsized to hold a 9mm bullet. Think of it as a "9mm Magnum", like a .38 and a .357 Magnum. It's a step up in power from a "forty", and a gun chambered for .357 Sig can hold the same amount of rounds as a .40 S&W.

    The 10mm was actually invented before the .40 S&W. The bullet is the same width, but the case is longer, and the round is more powerful. Think of it as a .40 Magnum. You won't be far off.

    .45 ACP is probably the most highly regarded (commonly available) self-defense caliber. It was invented in the early 1900's, for use in a Colt .45 Auto. Many people think that gun and it's offshoots are the best fighting handguns around.

    The .45 GAP is a Glock invention, designed to fit the power of a .45 ACP round into a narrower grip. The bullet is the same width as a .45 ACP, but the case is a smidge shorter.

    As you're just learning, don't let all the experts confuse you with their talk about things like how "the 9mm bullet really isn't 9mm wide at all"... at the start, just figure that the bigger the number, the more powerful the caliber. Find a shooting range that rents a wide variety of guns, and shoot a whole bunch, in as many calibers as you think best. When you find a platform you like, and a power level you're comfortable with, buy one. They're all plenty good enough for self-defense, as long as you can hit what you aim at.
  3. ugaarguy

    ugaarguy Moderator Staff Member

    Mar 19, 2006
    Ok, here we go on the semi auto calibers. First, the abbreviation ACP after a caliber stands for Automatic Colt Pistol, and most, if not all, of these rounds were invented by John M. Browning for pistols he designed for Colt or the US Military that were produced by Colt. "9mm" As everyone calls it is 9mm diameter x 19mm case length. This is the 9mm Luger/9mm Prarbellum/9mm NATO round. 9mm = .355" bullets, so yes your .356" and .357" 38 specials and 357 Mags are roughly 9mm in dia. The .380 ACP is 9mm x17mm.

    Next, the 10mm Auto is 10mm x(I believe)25mm. The round was shortened to fit 9x19 handgun frames and became the 40 S&W. The 40 S&W was necked down to hold 9mm bullets, and became the .357 SIG.

    After the success of the 40 S&W and 357 SIG, Glock decided to take the old .45 ACP (the orignal round used in the 1911) and shorten it to fit the 9mm handgun frames. This new short 45 is the 45 GAP (Glock Automatic Pistol).

    Confused yet? :D
  4. Ops Officer

    Ops Officer New Member

    May 18, 2006
    Welcome to the forum. I'll defer to others about the differences among the calibers you cited. Hopefully, you'll get more info than you can handle. But when you sort out these opinions, which will be laced with fact, please keep in mind the choice should come to what you are comfortable and effective with. As far as home defense, the most important thing is shot placement. A .38 spl is more effective if your shots hit your intended target consistently than a heavier caliber that you can't control, especially in a highly stressful situation. Also, keep in mind that the larger the load, the more penetration you can expect. I have no doubt my wife's 5-shot, .38 Spl will stop an attack from an intruder in the house as well as my array of .45 ACP pistols and revolvers because my wife and I can put all 5 shots rapidly in a small circle within the tactical distance of a snubby. And we are quite certain our ammo won't travel through an intruder and three walls behind him.
  5. kengrubb

    kengrubb Member

    Dec 28, 2005
    Bellevue, WA
    Cartridges of the World is a pretty good read on the subject. Pictures, history, even some loading info.

    To track down every cartridge with 9mm in it's name would take some doing. A few others are the 9x21, 9x23, 9x25, 9mm Glisenti, 9mm Action Express, 9mm Largo, 9mm Steyr, 9mm Ultra, 9mm Winchester Magnum, 9mm Browning Long, 9mm Mauser, 9mm Bergman-Bayard.

    However, as ceetee said, chances are darned good that when someone mentions 9mm they are almost certainly talking about the 9x19 or 9mm Luger or 9mm NATO or 9mm Parabellum cartridge.
  6. Cousin Mike

    Cousin Mike Participating Member

    Nov 27, 2005
    Columbus, Ohio
    Welcome to the forum, rogerjames!

    Here's the breakdown from my understanding. Since you are familiar with grain weights, and asked about speed and recoil, I'll just post some estimated, top-of-the-head figures.

    9x19mm - usually simply referred to as 9mm. Also called 9mm Luger, and 9mm Parabellum. Defense loads usually weigh 115 grains, pushed at about 1100-1300 fps., with 30-35k psi pressure. Recoil is often defined as 'snappy,' to me it's similar to .38 Special with lighter loads. With the hot stuff some of it can start to feel like .357 SIG. Good self defense round IMO.

    9x18mm - usually called 9mm Makarov. Never fired this round, don't know much about it, don't own anything chambered for it... but from what I read it can be a very mild or very hot round, depending on who makes the load. General concensus is that it's less powerful than 9x19, but suitable for self defense.

    9x17mm - Often called .380ACP, 9mm Short, 9mm Browning and 9mm Kurz. Defense ammo usually comes in 90-95 grain weights, vast majority of .380 ammo moves under 1000 fps. Recoil is slight, like a very light push - depending on the gun it's being fired from. I hear .380 can be wild in some of the really small pocket autos. Not a very loud round, not very powerful either.

    .380 is around the minimum for self defense for me personally, and lots of others.

    .357SIG - If I remember right, the .357SIG uses a 9x21mm round? SD load weights are offered from 115-147 grains, 125 grain being the most common. Most move between 1350-1500 fps, recoil is manageable but it comes back with some authority. Just under .357 Magnum in terms of noise, recoil. LOUD. Excellent self defense round IMO. Some .357 Magnum revolvers I've fired, although always louder than .357SIG, have given off less felt recoil.

    .40 S&W - Very little difference from .357SIG in my opinion. The round is slightly bigger and heavier, but moves just as fast. Defense loads usually are in the 165gr. neighborhood. The .40 seems to have more "torque" (push) than "snap," so some find .357SIG easier to control effectively. I like them both. Every bit as loud and flashy as .357SIG. Some .40 loads flash more than .357SIG in my experience. Excellent self defense round IMO.

    10mm - best description I can give is .40 Magnum, like ceetee said. Essentially that's what it is. General concensus is that full house 10mm is more powerful than .357 Magnum. Only fired 10mm on one occasion, in a Glock 20. I thought the recoil was manageable, but stiff... similar to .40S&W/.357SIG. Could just be the way that the G20 manages the recoil. 10mm is LOUD. Also one of the faster rounds... lots of people hunt deer with 10mm. Great self defense round.

    .45ACP - The manstopper. :D Probably will always be my favorite round. Big, slow, heavy, and powerful. Speeds vary, most defense ammo moves at about 1000 fps. - Pills weigh from 165-230 grains. Recoil is very manageable - usually described as a big, slow push compared to the 9mm's quick snap. Same noise level as 9mm (roughly). "Designed by John Moses Browning specifically for the purpose of killing human beings, and has arguably done that better than any other round for nearly 100 years," is how my CCW instructor put it.

    I'd have to say I agree.

    .45GAP - Stands for Glock Automatic Pistol, if I recall correctly? Don't know anything about the round itself... I think you get a prize if you can actually find one. :evil: All I know about the ammo that hasn't been posted is that it's incredibly expensive locally, and it's also really hard to find.
  7. rogerjames

    rogerjames member

    Sep 21, 2006
    Thanks for all the great info fellas. I have a much better understanding now. Will definitely shoot a few before I decide.
  8. miko

    miko Member

    Aug 10, 2005
    Remember also that revolver cartriges of the same power - caliber, weight velocity - could perform much better than similar auto cartriges, because the bullets can - and usually do - posess a more radical hollow-point, ensuring better, more reliable expansion at relatively low velocities.

    Putting a radical hollow-point on a semi-auto is asking for feed problems, except for 357 Sig which is a bottleneck cartrige.


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