Yes and no. Theoretically it is, and chances are if you have a relatively recent production P365, everything will interchange. We're talking extremes here, because the guns we got were very early release (and the class I went through was also very new at the time), and there were a number of teething issues that had to be addressed with the design between then and now.So not really like AR-15's as someone put it.
They were saying something like the Sig P365 is like Legos but for Pistols or along that line. AR-15 definitely is Legos for adults lol.