Larue Ultimate Upper Kit - Receiver Lockup Play

[GBMaryland]

So,

I have an OBR 7.62 that I picked up in 2011. Recently I picked up the UU kit in 6.5 Creedmoor to swap out the 7.62 upper and play with the new cartridge.

I was sighting in the rifle and the lower rail / bipod had a good amount of play. When I got home and started to check things, I realized the lockup between the upper and lower had SUBSTANTIAL play - I mean like USGI 1911 World War II slide/receiver kinda play!u

Has anyone else noticed the tolerances between older Larue receivers and newer upper being that poor?

I’m using an accuwedge at the moment, but i had to grind off about 1-2mils for it to fit.

GB

 

[Bigjake83]

Send the kit back and just rebarreled the OBR.

 

[Bigjake83]

Send the kit back and just rebarrel the OBR.

 

[GBMaryland]

Interesting idea, pita at this point. ...but that would work. The 7.62 upper lockup is fantasic - literally flawless. It seems they may have chaned the toleraces for the new uppers.

 

[Bigjake83]

Interesting idea, pita at this point. ...but that would work. The 7.62 upper lockup is fantasic - literally flawless. It seems they may have chaned the toleraces for the new uppers.

The tolerances with the new Larue UU Kits are shit!! Way to many variables.... The OBR isn't hard to take apart, Do yourself a favor and save $600 and have Compass Lake spin you up a new barrel in .308 or 6.5CM using a Bartlein blank. If you go 6.5CM get the +2 Gas system and use a JP Barrel extension.

 

[Primus]

Perhaps they are built so they mate with a wider range of lowers vs just larue. Makes sense since 90% won't use a large lower.