Send it Back Or Keep it

[sawacs]

Apparently, I have a receiver that is out of spec and creates a lip between the top of the hand guard and the top front of the receiver. Since there are no plans to run front and rear fixed sights on this build, I cannot imagine there would be any issues but it still bugs the crap out of me





Thanks

[howl]

How do you know it is not the handguard that is out?

[sawacs]

How do you know it is not the handguard that is out?

I have taken measurements of the upper receiver (1.829" from the bottom of the receiver to the top of the rail) and sent those to the manufacturer. They told me it looks like it is on the small end of the proper specs. Also, I placed three Aero Precision upper receivers up to the rail and they all meshed perfectly.

[85_Ranger4x4]

If it bugs you send it back.

[StoneHendge]

If that is out of spec, maybe something else is too.......

[mdram]

I have taken measurements of the upper receiver (1.829" from the bottom of the receiver to the top of the rail) and sent those to the manufacturer. They told me it looks like it is on the small end of the proper specs. Also, I placed three Aero Precision upper receivers up to the rail and they all meshed perfectly.

what should it be? and what are the tolerances?

[howl]

I'd send it back assuming costs weren't an issue. Your enjoyment is part of what you paid for.

[Kilco]

Send it back... once noticed it will forever haunt that upper!

[Troutguide]

Send it back unless you really need to use it asap.

[derek45]

Send it back, you'll be happier in the end.

[LRRPF52]

I have yet to find a handguard upper rail that matches an upper receiver when the 2 are made by different companies.

The best match is the LaRue Stealth 2.0 upper and handguards. You have to really look closely to see where the seam is.

[sawacs]

what should it be? and what are the tolerances?

The three Aero receivers I measured came in at 1.839" from the bottom of the receiver to the top of the rails where this receiver measured 1.829" so I am guessing the measurement should be 1.839" or right around there. The manufacturer told me their receiver was .010 undersized and to send it back.

[sawacs]

I have yet to find a receiver and rail that don't line up like they should when different manufacturers are used until now. However, I must admit the only uppers I have ever used for my builds are the Aero Precision uppers so I have no experience with others until now. I am sure there are some out there that have problems matching but I am only on build #8 and this was the first for me.

True story: A few weeks ago, I received an absolutely beautiful upper/lower matching set for a 6.8 build. When I put the upper and lower together, I could get a .020 feeler gauge between where the front and rear upper lugs mate with the lower. Also, there were no M4 feed ramps milled into the set: had to send that set back The excuse was we must have pulled that set out of our pile of rejects by mistake...LOL!

Basically, out of the last two upper receivers I have ordered from different manufacturers in the last three weeks, they have both been out of spec. Boy, what luck I have!

If the third one coming in this week is within specs, I'll be jumping for joy and do a few back flips!

[rabiddawg]

I think all of yall need some kind of medication.

[sreyemj]

I've always noticed a small difference similar to that between upper and rail. Doesn't bother me as long as it's symmetrical.