Q: What is the limit of replication in UBW? The highest level of NP (sword types) is probably Ea, but while it might be impossible for Shirou, could Archer make it? Also, under the meaning of weapons, to what extent can he make modern weapons? Must it be only blade types or can he make guns and mobile weapons?

A: Divine constructs like Ea and Excalibur are non-replicable. There might be some degraded NPs with similar performance in stock though. Also, since sword is becoming his origin, the weapons that he has stored are fundamentally limited to close combat.

Fate/complete material III; FAQ, pg. 134