USCIS gives no timeframe for the N 300 and the petition still goes to Dallas lockbox so hard to say which office will handle it or where the biometrics will take place for the concealed handgun permit
https://oregonchl.org/frequently-asked-questions/
Looking at Oregon instructions looks like showing proof of filing the N 300 is needed (not the notice of any approval)
You must apply for a concealed handgun license in the county in which you reside. Be a U.S. citizen or a legal alien who can document continuous residency in the United States for at least six months and who has declared, in writing, to the INS the intent to acquire citizenship (Form N300)