-> I'm not sure I fully understand the difference between a heavier
-> bullet and a hotter bullet. I grasp that a combination of grains and
-> velocity make the bullet heavy, but I don't know how one increases
-> or decreases velocity except by the grains.
Well, I think you are confusing bullet weight in grains with powder
charge in grains. Generally speaking, "hotter" refers to a cartridge
that has more powder in it than the usual load.  It will generate more
pressure and cause the bullet to travel faster.  Thus (to make up an
example, **NOT** a load recomendation!)  seven grains of Bullseye is a
"hotter" load than five grains of Bullseye would be.  Likewise, 38
special +P is considered "hotter" than regular 38 special because of its
greater pressure (22,000psi compared to 18,000psi) which gives its
bullets greater muzzle velocity.
"Hotter" is a slang term with imprecise meaning.  Heavier means EXACTLY
what it says:  a 147 grain 9mm bullet weighs 32 grains more than a 115
grain 9mm bullet.  Also, "hotter" really refers to a loaded cartridge,
not the bullet itself.
-> The reason I got the 147gr Federal Subsonic hollowpts is I assumed:
->
-> 1. quieter (subsonic)
-> 2. slightly more armour piercing (eg. able to shoot through a car or
-> a solid door)
Subsonic refers to whether a bullet's muzzle velocity will exceed the
speed of sound (approximately 1100 fps).  All bullets faster than 1100
fps are supersonic, all slower bullets are subsonic.  It's got nothing
to do with how loud the cartridge sounds when fired from an unsilenced
gun.
In the case of the 9mm, all the regular cartridges were supersonic.  The
147 gr subsonic round was developed specifically for use in SILENCED
submachine guns.  You see, a supersonic cartridge, even when fired from
a silenced gun, will still make a loud cracking sound when the bullet
breaks the sound barrier - just like a jet aircraft's sonic boom, but on
a miniature scale.  Subsonic rounds don't.
BTW, the correct terminology isn't silencer, it's suppressor.  Many so
called "silencers" don't actually silence a gun, they just lower the
amount of sound the gun makes.  Thus they are "sound suppressors".
Sorry if I'm being overly pendantic on the usage.  I'm guessing from
your sig that English isn't your native language.  American English,
especially our slang, can be a might confusing to people who didn't grow
up with it.
Generally speaking, the ability to shoot through doors varies, depending
on a number of factors; bullet construction, bullet speed, & bullet
energy are the principal ones.  A faster bullet is usually more
penetrative than a slower one, a Full Metal Jacket usually more
penetrative than a Hollowpoint, etc.
-> What I want is
->
-> 1. quiet, low flash
You'll have to buy different rounds from the various companies,
Remington, Winchester, Federal, etc. and try them in your gun to check
flash and noise levels yourself.
-> 2. very piercing (cars, doors)
This is not really a good idea, in my opinion, for self-defense
ammunition.  A round that will penetrate doors will also probably shoot
right through a human being.  If you are forced to shoot somebody in
self-defense, and the bullet exits his body and hits an innocent
bystander that was standing behind him, you are now in a **HEAP** of
legal trouble, no matter how justifiable the original shooting was.
Depending on whether the bystander lives or not, expect a criminal
charge of Assault with a Deadly Weapon or Manslaughter and massive civil
suits from the bystander or his survivors.
If you feel you may run into a tactical situation requiring such
penetration, carry such rounds in an extra, spare magazine.  With
practice, you should be able to switch magazines in two to three
seconds. Hopefully, while behind cover yourself.
Last time I looked, 130 grain Full Metal Jacket ammo is about as
penetrative as it gets, at least as far as legal-for-civilians ammo
goes.
-> 3. heavy damage (large hole)
Hollowpoints are the way to go to get this.  Federals 115gr 9BP round
has an OUTSTANDING reputation and you can scarcely go wrong with this,
as long as it feeds reliably through your gun.
-> 4. no damage to my P-1
None of the commercial cartridges from ANY of the ammo companies will
DAMAGE your gun.  Some of the "hotter" rounds, such as Corbins Plus +
9mm rounds might accelerate normal wear somewhat.  Thats the price you
pay for the improved performance.
Regards
John
--- WILDMAIL!/WC v4.12 
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