Buffalo NY 槍擊案

itoen

TKMRSK 发表于 2022-5-15 20:48
https://www.underwoodammo.com/10 ... treme-defender.html
这个速度更快点

一般认为，fmj比jhp穿透力大，要不以后ccw防身换fmj吧。

itoen

easycity 发表于 2022-5-15 19:53
据初步报道，上个星期六在Buffalo, NY行凶的18岁枪手，被超市的保安击中，毫发无伤，还把保安杀了。这是几 ...

找到一个一般认为

Unfortunately, there is an extremely prevalent misconception about bullet impacts in this reddit, and I see it surface again and again in discussions pertaining to armor and helmets.

In every discussion about helmets, I see people saying “Even if the helmet stops the bullet, you would die from the shock, your neck would snap etc. Etc.” This is just plainly wrong, and people need to stop spreading this nonsense.

So once and for all; Bullets do not kill because of the force they exert on your body. Bullets kill because a force is concentrated into a very small area (the bullet), causing it to penetrate your body and do a lot of damage. So bullets do not kill because of a large force, but rather because of a very high “Force density”. This very well exemplified by considering the firing of a rifle. Due to Newton’s third law, the same force that accelerates the bullet is also exerted on the rifle. However, since the bullets mass is roughly 1000 times smaller than the rifle’s, the acceleration is 1000 times smaller. This is why you don’t die from the recoil when firing a rifle.

So how does this relate to armor and helmets? Lets assume a bullet impacts on an armor plate or a helmet, and it is completely stopped. That is, no penetration, and no sizable backside deformation. In this case, the bullet transfers its momentum to the armor plate/helmet, exerting the same force as was used to fire it. However, the mass of the helmet/armor plate is comparable to a rifle, I.e. 1000 times larger than the bullet. The bullet impact on armor plate/helmet is thus comparable to the recoil felt in the rifle that fired the bullet.

Imagine putting on a helmet, placing the buttstock of your rifle against your helmet and squeezing the trigger. Do you think you would become brain dead, or that your neck would snap? No? Then stop saying this would happen when a bullet impacts a helmet!

“Then why is so difficult to make helmets withstand rifle calibers?” It’s not difficult to make a helmet capable of withstanding rifle calibers. It’s difficult to make such a helmet while keeping it light enough to be practical. A helmet needs to cover most of your head, while at the same time only weighing a couple Kgs at most.

itoen

easycity 发表于 2022-5-17 13:44
这么说吧。射击发烧友平时一直买子弹，家里保持几万发子弹。遇到枪击案，再买几万发。
枪械发烧友一直买枪 ...

这听起来不像发烧友，倒像临时抱佛脚的，或者凑巧事发连贯，短期内多次抱佛脚的 （佛说，放过偶吧，我有脚气）

发烧友不是应该平时没有来由的就一堆枪一堆弹，隔三岔五的把靶场当夜总会逛么。 遇到这样的新闻，发烧友一般是抱着看笑话的心态，呸，让你们平时歧视偶，把偶当怪物，然后照常岁月静好，生活本来就应该是这样。有份世界因为有了偶才不乏味的得意。