The "LM5" looks like an R5 (then again the R1 was based on an LM design

)
I've only shot with R4's, R5's, an LMG's and 9mm's (incl the UZI - piece of junk though :/) before ... and yes although the .22 is a real gun I'm not listing it under military issue ones.
Had tons of fun on the farm with the .22 rifle + silencer and scope.