Upper Differences?

[lalakai]

maybe it's a blind spot for me, but i'm having trouble seeing how significantly it can affect the platform, based on different uppers. Barrels and triggers i can see. But when i look at the different uppers (LMT, CMMT, LaRue, etc.) they are all mil-spec; some are beefier, but the basic configuration is the same.

The barrel is the actual carrier for the projectile, and the trigger will cause problems if too hard, or not smooth, etc.

Hopefully someone can enlighten me. I don't mind spending extra as long as it's justified.

thanks

edit = grammar fix

[nksmfamjp]

I don't get it either. For my money, the Spikes A3 Upper is great. I can't see why I want the VLTOR or Larue. The LMT MRP, however is an interesting platform, but I'm fine just changing uppers.

[rob_s]

If you mean the stripped down hunk of aluminum, I'd be inclined to agree with you. Buy a stripped CMT upper for $100 and motor on, unless you just want billet or an upper with an integral rail (like a Vltor VIS or LMT MRP).

If you mean that buying a Spike's tactical complete A3 upper with barrel, bolt, charging handle, and handguards, then I couldn't disagree more.

[C4IGrant]

Couple things. The LT upper receiver is billet. The VLTOR MUR used to be billet, but is no longer.

Upper receivers are mass produced items that are sold to distr. for around $50. The manufacturer has maybe $25 in them. So when you are dealing with mass produced items like this, attention to detail (meaning making sure that the rail is square and true) is NOT a priority. This is where the LT Stealth and VLTOR MUR come in. They do pay attention to detail (which is why they are more).

So why does this matter? Well, if you are going to put a magnified optic on said weapon, you do NOT want the rail canted in any way. If you going to use an Aimpoint or EOTech then it does not matter what you use.


C4

[lalakai]

good point about the rail and alignment where optics are concerned. I can see the importance of having a stable solid frame to hang the components on, but i didn't know if there was a noticeable difference in specs and quality control, for the uppers. it's looking like there's more of a difference then i was first thinking. Hopefully the M4 i'm building will never be fully tested, but it will be used under harsh conditions and i pretty much demand that it functions well. I don't mind paying for quality, but i hate paying for "name" when the name-quality is the same as generic.

thanks for the input. hopefully others will add their knowledge so i know just how deep to dig in the wallet

[nksmfamjp]

I hope this is all making sense. There are upper receivers which are just a receiver and there are upper receivers which also have the handguard built in. The primary advantage of built in is a single continuous upper rail. A separate handguard always requires tedious alignment and generally all optics are mounted to the receiver with a special mount.

In the case of a duty M4, I think the mil guys use the separate handguard exclusively.