Is there a way to rip MW3 maps?

Well im sure a few talented people on facepunch will know!!

short answer: There is no process/application to rip a map from MW3 for use in the source engine.

To get a MW3 map into the source engine you’d have to rebuild it in hammer and rip/import all the MW3 models and textures that the map uses.

Wrong section dude

Check the mapping section and ask there.