Bushmaster Serial # Prefixes

Can anyone tell me the difference in BFI and L prefix Bushmasters?

Both of mine are “L”. DOM late '90’s.
It’s my understanding that “L” is made by http://www.larmanufacturing.com/ and “BFI” is made in house at BM.

That was my understanding also. I bought a L prefix bushmaster lower in 1998.

Is all the new stuff BFI?

Hootbro

I bought a L- prefixed Patrolmans Carbine in 2005 and then a B- prefix Patrolmans Carbine in 2007.

I was under the impression the BFI- prefix is in house manufacture as well.

L- was LAR I was told.

Could probably get a definitive answer from Bushmaster directly.