关于223/5.56弹药问题。

SemperFortis

yankeealpha 发表于 2013-11-12 20:52
最开始的是55 grain M193在M16 1/12 rifling 后来62 grain M885用在M16A2 1/7 rifling 个人认为> 62 grain  ...

差不多。目前流行的1:7, 1:8和1:9都能打50gr以上的，基本上除了特轻特快的那些varminter弹药，啥都能打。

楼主，平时烧子弹或者练习可以用最便宜的铜壳弹，比如上述的golden wolf, pmc等55gr;

军剩弹药一般都是62gr， 比如北约各国的SS109。最好的是美国和以色列的m855. 但很多靶场不允许因为里面有钢芯。硬物侵彻力太强而且打到金属和石头会起火花，容易着火。

好的弹药就是竞赛弹了, 最便宜的竞赛弹应该是PPU的，美国能买到最好的厂弹竞赛弹是federal gold medal match (FGMM)，想知道你的枪能打多准，买一盒回来打几组。FGMM的替代品是hornady，前者买不到的时候。

打猎可以用重点的竞赛弹，比如75gr, 69gr。当然更好的弹药是猎弹，比如Barnes TSX.

SemperFortis

不建议remington umc, 很差的弹药。同价位的, pmc不错

SemperFortis

yankeealpha 发表于 2013-11-13 14:15
Question 1: Which rifling can handle 45 grain varmint ammunition?

Suggestion 1: Also, a lot of ra ...

1:9 is the mininum i think. modernized ammo jackets can handled the "faster" spin rate so they don't easily come apart. From what I heard 1:9 is also enough to stabilize lighter bullets.

but you don't want 1:9 in your ar unless you absolutely want to shoot everything with just one gun.

SemperFortis

graycat2006 发表于 2013-11-13 15:16
6mmBR.com 的数据:
Max Bullet Weight:

他的意思是每个twist rate最轻的弹头。 1:9 打45gr没问题吧？

SemperFortis

yankeealpha 发表于 2013-11-14 14:01
Question:
My understanding is that 'slow' twist cannot properly stabilize heavy bullets as there is ...

Very light bullet and fast twist rate = jacket seperation

For example 40gr vmax in 1:7, the thin jacket will come apart at high rpm. Unless the bullet is made of different construction, such as solid copper.

Rule of thumb is to stick with 55gr or heavier for 1:7.