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View Full Version : Why are 9mm fmjs made so pointy?


Ben86
January 19, 2009, 01:57 AM
I know that this is sort of a silly question, but it's been on my mind for the past week. With the potential for over penetration with standard 9mm fmj being so high why are most made so pointy? As opposed to being more round like the .45 fmjs or better yet flat nosed like most .40 fmj bullets.

Does it improve function? What is its purpose? Its reason?

9mmepiphany
January 19, 2009, 02:45 AM
you're asking the question backwards.

it should be, "why are the bullets in .40 not as pointy?"

the .40 bullets are shorter so that they will fit into the same lenght magazine/action as the 9mm. also as calibre goes up, for any given weight (remaining proportional), the bullet will be shorter.

the 9mm was originally designed with a 124gr bullet, that determined OAL. as lighter bullet, to maximise reliable feeding, would be pointier to try to duplicate the lenght

armoredman
January 19, 2009, 03:17 AM
Luger was the first 9mm, magazine was angled pretty hard, so a severely pointed bullet ogive allowed good feeding. One possible reason, I should say. :)

Kind of Blued
January 19, 2009, 10:02 AM
I say the pointier the better. It's like stabbing and shooting at the same time. :)

Anyway, 9mmepiphany has got it. Cartridges are generally released in one form, then people/manufacturers mess around, loading lighter or heavier bullets for different effects. Those bullets are made of the same material, and are the same caliber, so the heavy ones are longer, and vice versa. Things have to extend into the brass case, or out of the brass case.

expvideo
January 19, 2009, 10:04 AM
Because that's the pokey end.

franconialocal
January 19, 2009, 12:07 PM
Did somebody say "wadcutter"??:):D

9mmepiphany
January 19, 2009, 05:24 PM
Did somebody say "wadcutter"??

in 9mm?

actually that's a good example of weight/lenght and the standard loading for the .38 spl is 158gr whereas the wadcutters run right around 148gr

Dr.Rob
January 19, 2009, 09:36 PM
If its not going to expand, 2 holes are better than one. I'm sure thats the military reasoning.

Beagle-zebub
January 19, 2009, 10:10 PM
If its not going to expand, 2 holes are better than one. I'm sure thats the military reasoning.

I've heard of thinking along such lines before, but isn't it actually the case that bullets with flat ogives, such as wadcutters, cause greater permanent cavitation, even controlling for expansion? I have to think they'd still exit, too, given that they aren't expanding.

Ben86
January 21, 2009, 12:46 AM
As far as fmj, the military reasoning was based on economics and politics, not what works best at killing the enemy the quickest.

Good thing specops don't have to worry about much of that and enjoy modern expanding bullet technology regularly. :)

jpwilly
January 21, 2009, 01:28 AM
That poor 9mm will need all the help it can get. That's why it's so pointy! :neener:

Claude Clay
January 21, 2009, 01:34 AM
for those who reload in the dark, pointy end makes it easier to know which end is up

Gun Slinger
January 21, 2009, 03:35 PM
I suspect that it has more to do with reliable feeding and chambering than anything else.

The smooth, tapered contour of the FMJ ogive offers no sharp edges to hang up on crudely machined or steeply angled feed ramps and the relatively hard guilding metal (usually 90Cu/10Zn) jacket doesn't deform as readily as lead does, so there is nothing to snag on sharp interior edges.

Smooth, hard and tapered makes for smooth feeding and chambering.

:)

redneckrepairs
January 21, 2009, 03:46 PM
The 9mm came in on the literal " dawn " of recycling handguns ( here recycle means a slide lol ) . The round is " pointy " because at the time auto weapons were new , and no one understood how the feed cycle worked , nor how the angle of feed could work . Nowadays you can buy all sorts of ammo for the 9mm up to and including some " flying ashtray " loads. However if its 9mm then that " pointy " full patch load will likely run in any pistol , kinda the same as back when .

barnetmill
January 21, 2009, 05:57 PM
Functioning is important. but a nato spec pointed 9 mm also has great penetration. Some of the military barrel if I recall correctly also have a fast rifling twist that might aid penetration. When the 9 mm was invented people were still fighting from horse back and winter clothing was very heavy, both of these call for max penetration.