BC question

[FALrunner]

I have a bolt carrier with what I think is a pretty dreadful level of finish machining. Please look at these pictures and see if I'm just overly sensitive, or if you agree that machining of them should be a little less rough.

I have emailed and called the manufacturer. Awaiting a response from them at this time.

8078

8079

8080

[Sanpete]

It's unfortunate that the question, "how does it shoot?" seems rhetorical right now.

[Scorpion]

If it still functions 100%, you're being overly sensitive. Put it in a weapon and go out and shoot it.

Just my opinion of course, but if it bothers you that much, then see if the manufacturer will exchange it. Or, buy another and keep that as a spare.

[Belmont31R]

It looks a bit rough in spots but the parts that touch the receiver look smooth.

[021411]

The rails/bearing surfaces look smooth. It's hard to tell on my screen but is that nickel boron'ed? It's either FZ, ST, or R-Guns. Only three that I know of that put something out with the NiB treatment.

[Quiet-Matt]

Your just overly sensitive, like the others said the bearing surfaces look fine.

[sonofagun2012]

I've seen several bcg that look like that and thought the same. I was told that it was fine and it didn't mess with the cycle of operation. So I wouldn't get my feeling hurt over it's looks long as it works.

[az doug]

As others have pointed out, the four bearing surfaces that matter look fine. The rest is merely cosmetic and has nothing to do with function.

[markm]

As others have pointed out, the four bearing surfaces that matter look fine. The rest is merely cosmetic and has nothing to do with function.

Agreed.

[ZRH]

If it works etc.

I will say those look like chatter marks which would be weird on a turned piece. Looks like someone missed it in visual check, or they didn't polish it before parkerizing. That would be a blemish/second and I would call about it.

[FALrunner]

Thanks to those with useful comments.

I'd like to say that not _everyone_ needs to hear the "does it shoot reliably" speech. If we have have looked here, and read comments, and learned here, then we (well, I, for sure) already know that. However, I'm sure you can't know that because you don't know me. No harm, no foul.

There are, on occasions, other, additional questions in play in a post of this nature. For example, in this case, if the initial rough machining is also an indicator that potentially the rails (rails? the bearing surfaces on the BC) are out of spec, then that would be a good visual clue for me. Do I know that? No. Do master armorers here know that? Probably. Hence, my initial questions. Perhaps I should have been more explicit.

Also, where the forward assist notches are cut INTO the rail (rail?), the bolt carrier is literally sharp enough to cut into whatever gets in its way. Should I care about this? Maybe, maybe not.

Is the machining on this part equivalent to that on a Colt? BCM? LMT? I don't know, I don't have those to compare with. According to pictures I have seen, I believe the QC on this part is of a lower standard than Colt, BCM, LMT, and DD. Believe, yes. Know? No.

And no, my feelings are not hurt (for the crowd who are thinking that). I tend to me more of the "engineer in the corner" with my questions.

The manufacturer has responded to my inquiry with a request for more information, which I have provided. I anticipate an amicable outcome for all. I'll post an update when it's all finalized.

[Belmont31R]

Slight cuts into the rail below the notches for the FA are not abnormal. I have them both on a BCM and Colt BC.



I don't think its anything to worry about, and especially not when you see sand cut carriers. If tiny little cuts into the rail will cause a problem my SR25 should have shattered to pieces by now:


http://i274.photobucket.com/albums/jj245/BM31R/e6a4b942.jpg

[mtdawg169]

Is is possible that the finish allows imperfections that would normally be hidden by the parkerizing process to show through?

[ZRH]

Slight cuts into the rail below the notches for the FA are not abnormal. I have them both on a BCM and Colt BC.

I don't think its anything to worry about, and especially not when you see sand cut carriers. If tiny little cuts into the rail will cause a problem my SR25 should have shattered to pieces by now:

[IG]http://i274.photobucket.com/albums/jj245/BM31R/e6a4b942.jpg[/IMG]
The pics are gone now but they didnt look like sand cuts. They looked like chatter marks like when you dont properly tighten workpieces in a mandrel.

[Eric D.]

Absolutely. Chrome plating, especially, will "amplify" any surface imperfections.


Is is possible that the finish allows imperfections that would normally be hidden by the parkerizing process to show through?