LaRue 6.5 Grendel Rifles

[revaew]

Sorry for bit of a necro post, but I had a question about the upper kit. So I didn't order a Larue lower to go with my 6.5G UU kit as I already had several lowers laying around my house. While the Larue upper fits like a glove into the lowers, the outside of the receivers do not match very well. In some places the upper is wider and in others my lowers are wider. The back of my lowers, where the buffer tube attaches is wider than the back of the upper and i can see into the buffer tube, albeit slightly. This is true in several spots. Has anyone else experienced this? They are SAA, bushmaster, PSA, BCM, and Aero lowers and are all marketed as Milspec. I read than any milspec receivers should work fine but the fit of basically every other combo of receivers I have appears better. I may be over reacting, but I have never had an upper and lower go together like this. Am I over reacting? Thanks.

Here is a picture from both sides, looking at where the receivers meet. It is more or less like this for all lowers that I have.





This last picture I used a stripped lower so the gap could be seen more clearly.