M4 and 551 replica trouble

[sethb7290]

the parts in question are the 551 replica and the upper receiver on my M4, the issue is that when i placed the 551 onto the flat top it was slanted to the left (the angle of the camera makes it look like the whole receiver is slanted but it's straight) the thing is i want to make sure what is causing this problem hopefully its the upper receiver. now in the first photo it makes it look like the front sight is crooked but it is straight i triple checked to see it was properly aligned.




i just received a 551 replica last night and i noticed something on the underside of the sight, it looks like a piece was grinned off or something which may be a factor to why its slanted.


the other probability is the upper receiver itself, the picatinny rail on top is crooked where it seems to slope down to the left. (this is the one i believe is the issue)



any comments that can help, will be appreciated.

[XavierMace]

I would check the front sight again because it doesn't look straight in either of those pictures.

[sethb7290]

i just straightened the front sight but the problem is still there so it cant the front sight.

heres a new photo for reference on the front sight

[RecoilEF]

I am the previous owner of that Eotech 551 replica. I gave it to anguyenmp and he sold it for me. I had the same problem you did with it canting to the left, G&P did a bad job on their 551 replica's and messed up the rails. I simply grinded away the rail clamp on the right and it fixed the problem for me, it was a messy job but it worked. We must different uppers since the problem is worse than ever on yours.

[sethb7290]

I am the previous owner of that Eotech 551 replica. I gave it to anguyenmp and he sold it for me. I had the same problem you did with it canting to the left, G&P did a bad job on their 551 replica's and messed up the rails. I simply grinded away the rail clamp on the right and it fixed the problem for me, it was a messy job but it worked. We must different uppers since the problem is worse than ever on yours.

i really hope for my case its the upper because if you could see it in person you can definitely see that the flat top slants downward to the left. what company was your receiver made by? the one on my M4 is a AG-K which is poor quality as it is

[RecoilEF]

I have a King Arms metal body. Actually both of them are almost completely King Arms aftermarket externals. Good stuff, I recommend all their external accessories. Its mostly the fault of the Eotech, the rail clamps are way off its embarrasing. You could try to grind off more where i had already started, i never finished the job completely.

[sethb7290]

I have a King Arms metal body. Actually both of them are almost completely King Arms aftermarket externals. Good stuff, I recommend all their external accessories. Its mostly the fault of the Eotech, the rail clamps are way off its embarrasing. You could try to grind off more where i had already started, i never finished the job completely.

well ill look into King Arms receivers to see if that can solve it like you said.