I cannot seem to find an LMT 11.5" barrel for a regular LMT MRP MLOK upper.

I have a 10.5" barrel for what appears to be an LMT MLOK 9.25 upper, but I'd like to pick up additional LMT barrels for it...specifically another 10.5 and an 11.5.  The only ones I've come across seem to be for the MRP CQB upper receiver. I don't see any difference between the CQB and standard MRP upper other than the pic rails, I could be wrong.

This 11.5 is specifically listed as being for MRP CQB receiver and not the full size MRP rail. The other 10.5" barrel is also for a CQB receiver.

I'm aware of the conversion options available by some machinists (dwilson in particular), but I'd like to stay with LMT barrels.

LMT's website makes NO differentiation between barrels for CQB receivers or "full size" MRP receivers for some barrels. For example... this 11.5" barrel. I do see other barrels like this mentioning the L7X1A vs L7S1A, but why do other sites list it as CQB only?

Anyone have any guidance they could offer?

I believe I may now understand LMT parts ID for this...

The L7X1A is the designation for the MRP rail I have and the 11.5" barrel offered is only compatible with the L7S1A?

Does anyone know what the difference is between the quad rail L7S1A and the L7X1A?

The only difference between the two pic rails MRP / CQB uppers is length of rail. The shorter barrels will be covered completely by rail including muzzle.