Ole La. redneck with upper/bolt carrier problem

[PPCDAVE]

Hello my friends!  I’ve gotten kind of obsessed with building 80% lowers and just finished my first 308.  Finally got past the lack of knowledge concerning buffer assembly required and a problem with an “enhanced” bolt stop, And thought the weapon ready to fire. It is fitted  with a side charging upper purchased from one of the well known/often disparaged manufacturers.  Well, while inspecting the upper I noticed it had what seems to me an excessive amount of clearance between the bolt carrier and the upper receiver.  With the bolt locked in battery I can move the rear of the carrier 1/4” up and down !  My other AR uppers all have wiggle room, but NOTHING like this!  I’ve emailed the vendor but haven’t heard back from them yet.  Of course the carrier is contained by the buffer tube when cycling, but…

Does anyone have any experience/knowledge/thoughts on this issue? Is it safe to fire?

thanks for any information!

[Armed Eye Doc]

Welcome to the forum. 

There will need to be pictures, parts lists and possibly videos before any reasonable solutions can be suggested.

[Lonewolf McQuade]

Welcome to the forum @PPCDAVE

[jtallen83]

Welcome from Iowa!

[PPCDAVE]

Here are some videos showing bolt carrier movement in upper.  I think that when assembled to lower, contact between top of cocked hammer and bottom of carrier limits up/down movement, but still…Upper was bought complete, assembled.

[Rsquared]

Welcome aboard from Maryland.

[edgecrusher]

Needs parts list to try to solve tolerance stacking issues. Also, has the bolt been headspaced to the barrel?

[shooterrex]

That looks like a bear creek upper. They should have head spaced it before it left the factory.

 

[DustBuster]

My standard bolt carrier only wiggles in the back when lugs are engaged about 1/16” side to side 1/8” total movement.  Seems like a tighter fit than yours

[PPCDAVE]

 This is a BCA complete upper, assembled by BCA, so it’s all BCA parts. 

[PPCDAVE]

Finally got a reply from BCA today; they said a “small” amount of play in Thr bcg wasn’t unusual in the side chargers because they’re made differently.  Seems to me that 1/4” is not a “small” amount, but we will see when I fire it.  More will/may be revealed.