问问ar15 upper 和枪管的匹配问题

akak47

准备自己装个ar15. 在看upper 和管子的时候遇到个问题。 有的upper 分有M4 feed ramps 和没有两种。 是不是如果枪管有M4 feed ramps， upper就需要有M4 feed ramps。 还是枪管有了M4 feed ramps， upper就不需要了？ 求帮助

kisskaren

M4 Barrel extension 一般都有, barrel的其他讲究就多了去了。

Upper Receiver要买M4的，有两个预带的小槽。高级的Upper推荐Vltor MUR larue stealth mega LMT等，二手的也不贵。便宜的forgedUpper我个人推荐BCM的blem upper, 79-89块，很划算，一般是BAFE（方块标http://www.baforging.com）做的。或者Anchor Havery做的，AH标。尺寸规格和表面处理质量稳定。

iPad 其他讲究就不多说了，自己首先要有明确的用途和充分的知识，知道怎样配和装，为什么这样做。注意螺纹的防锈死，扭矩，barrel nuts装正，gas tube free, gas block装好并减少震动，muzzle device的共振和回流，怎样accurize等等。GL!
另，Bill Alexander 建议他的6.5要用loctite bedding barrel extension 和GB, 我的223只弄了GB，搜发搜古德。

journey

M4 profile in the upper was created to solve the rapid fire feeding problem for the GI. It is not something you must have to shoot the gun but definitely nice to have for a little extra or even the same cost. There are a few combinations that you will see if you build your own upper.
If you have M4 feed ramp barrel extension, you should get a M4 profile feed ramp upper. So they match. If the upper doesn't have the M4 feed ramp, you can file the two grooves yourself an touch up black "alodine" or cold blue, whatever chem film solution.
If you have a non M4 barrel extension, do not pick an upper with M4 feed ramp. It will cause the tip of round to get caught at the gap.

akak47

感谢各位的回答