Originally Posted by BigEd
Domestic Munich malt is essentially a specialty malt.
Briess 10L Munich has a diastatic power of 40 and can be used at 100% of the grain bill, similar to Weyermann Munich I.
Briess 20L Munich has a diastatic power of 20 and can be used at about 80% of your grain bill. Again, similar to Weyermann Munich II.
edit to say:
"Similar" in that it'll make beer, not saying it'll be nearly the same or as good as using the real thing.