AR Sponsor
Posted: 9/18/2005 12:13:57 PM EDT
| The A2 Upper on this rifle is supposed to have M4 cuts to match with the M4 extension on the pencil barrel. Are the cuts made before the anodizing, as they are on the flat top M4 receiver or after? |
|
I just got a 6520. There is no "4" marked on the upper receiver. There is a "4" marked on the barrel or the barrel extension (can't remember). You can only see it if you take the barrel off, and that's when I noticed it. The upper receiver is an A2, but it is cut for M4 ramps. |
A "4" stamped onto the face of the barrel extension is a COLT M4 barrel extension  Is there anything stamped onto the front of the upper receiver, right above the gas tube hole ? |
| I think that Colt simply used parts on hand to put some of these together. The barrels/extensions were the M4 type, but the available uppers were not. So, they just took the standard A2 uppers they had at the time, dropped them back in the assembly line and cut the feedramps to match the barrels/extensions, but did not re-anodize them. |
I cant imagine COLT doing something like that... |
Agreed. My NIB 6520 is included in this description. The M4 feedramps were cut into the upper, not originally forged into it. They look ok for my taste, but I'm curious to hear how this pans out. |
|
I like Colt, believe they put out a quality product, and am not trying to bash Colt. Both of my AR's have Colt uppers. One is a 6520, and has the M4 feedramps done after anodizing. But, this seems to be more than just one or two occurances and rifles/uppers with this trait seem to have come from more than one source, so I do not believe some unscrupulous vendor is behind it. I also recognize the demand for these LE/Mil rifles and do not find it unbelievable that any company would use whatever they have on hand in order to meet that demand, even Colt. That said, I don't think these are defective uppers in any way, they were just modified to the new standard (M4) a little late in the assembly process. BTW, my 6520 upper with un-anodized M4 feedramp cuts is running fine after a fair bit of use with no discernable wear to the feedramp cuts in the receiver. |
All feedramps are cut into the upper. The question being presented is if they are cut before or after anodizing. |
Right. And to clarify my theory a little more, I DON'T believe that Colt "dremeled" these uppers. I don't know very much about the machining involved for finishing an upper receiver forging, but I would assume Colt has a specific step in the process for uppers designated to be M4 uppers in which the CNC machine, or whatever, cuts the feedramps. These uppers were simply put back in and that step applied later than normal. |
I don't know when mine was made ( sn: LGC 034XXX ) but the M4 ramps are shiny. No wear that I can see but I only have about 800 rounds through the gun at this time. I am not gonna sweat it unless I see it become an issue. Also, for reference, I have no "4" marks anywhere on or in the upper or upper components. |
AR Sponsor