Build AR Upper or Buy BCM One?

[tiro6]

Hey THR!

So I recently took the plunge and bought a stripped lower to start building what will hopefully be my dream AR. In doing research and all that, I found a lot of threads talking about either upper build parts or completed uppers, but haven't seen one that compares either building one or buying one thats almost completed. So heres my question to you all - am i going to get more out of a spec'd out build or would i get equal results and possibly more savings with a built upper group.

So here's what I was planning to do with a build upper:
-Vltor MUR upper receiver
-BCM 16" BFH midlength lightweight barrel
-low profile gas block

vs. complete BCM upper (this one: http://www.bravocompanyusa.com/BCM-BFH-16-Mid-Length-Upper-Receiver-light-weight-p/bcm-urg-mid-16lw%20bfh.htm)

If i went with the BCM upper, I would shave down the FSB. So what are your thoughts?

 

[Tirod]

Accuracy in an upper build is based almost entirely on the barrel. A mid weight barrel from the better suppliers will do a better job. Uppers themselves don't do much at all, simply because all they provide is a channel for the bolt to reciprocate and lock up into the barrel extension. There's no stress on them other than the operator holding them, the pressure of the cartridge is entirely contained between the bolt face and barrel extension.

These things aren't like other guns, there's a different set of rules.

The bolt and carrier are more important, and that's been left out entirely. In use, the only major feature of the upper is going to be whether it's railed or not, which means A4 or retro. Very few attempt retro high accuracy builds, the handle interferes with mounting optics with any reasonable attempt at ergonomics.

Concentrate on the barrel, bolt, and carrier, you'd be money ahead. Expensive railed tubes or handguards are just accessory mounts. It's your choice, but I don't see where a $400 tube contributes as much as a $400 barrel. To shoot accurately, the barrel is required first, the tube just adds an increment of protection against disturbing it. It cannot and will not add accuracy beyond what the barrel can do.

These things aren't like other guns, there's a different set of rules.

I bought the best barrel I could afford, mounted it in a blem upper, and called it good.

 

[henschman]

For my builds, I figured that I couldn't really save any money by building my own upper, and it would involve a lot more work and buying extra tools. But I have to say it would be cool to be set up to do your own barrel swaps... I would like to do it eventually. I have no need to now though. The only way I would probably do it is if I wanted a barrel that I could not obtain on a complete upper by itself, like some kind of custom job, retro build, etc. But if you want something common like a BCM middy, I would just buy a complete upper and save yourself some trouble. I would pass on the MUR too... I haven't heard any stories about mil-spec uppers failing, so I don't really see the point in carrying around the extra weight of a beefed up upper receiver.

 

[cfullgraf]

Generally, my builds are more expensive than the Plane Jane commercially available uppers. But, my builds are generally not available as an off the shelf item. I am always using higher quality components or a combination of components that would only be available as a custom assembly.

I enjoy assembling the rifles. You get up close and pesonnal and sometimes even put yourself into the work in the form of scrapes or skinned knuckles.