Sig M400 Patrol .223 - Will LaRue 6.5 Grendel fit?

[Glenn54]

I'm new to the AR scene My first AR is a Sig M400 Patrol. I am thinking about getting a LaRue 6.5 Grendel upper but now sure it will fit. Does anyone know if this will work? Thanks.

[HD1911]

I'm new to the AR scene My first AR is a Sig M400 Patrol. I am thinking about getting a LaRue 6.5 Grendel upper but now sure it will fit. Does anyone know if this will work? Thanks.

I don’t see any reason why it wouldn’t. Go for it. It may either have a little slop and be wobbly, be rock solid, or somewhere in between. But it should mate right up.

[Smokin338]

m400 is just a standard mil-spec AR... good to go

[ST911]

m400 is just a standard mil-spec AR... good to go

Will-fit for purposes of this discussion.

Not a bad rifle, but not a "standard mil-spec AR" otherwise.

[Glenn54]

Thanks for the feedback. Can you add a little detail to what you said? I'm trying to learn as much as I can. I certainly have a long way to go. Thanks.

Will-fit for purposes of this discussion.

Not a bad rifle, but not a "standard mil-spec AR" otherwise.

[ST911]

Thanks for the feedback. Can you add a little detail to what you said? I'm trying to learn as much as I can. I certainly have a long way to go. Thanks.

If you head over the ar technical discussion subforum and browse the stickies, you'll see some pretty comprehensive discussions on what that term means, when and how it applies, and matters, what the specifications are, etc.