I purchased two new long guns last summer.
One at Ramsey Outdoor the NICS didn't come back instantly so I went home thinking I would get a call on the next business day. It was Independance Day weekend. I got the call before I got home and went back to pick up my .243.
A few weeks later I went to Simon-Peter's open house. I got a good deal on a Savage 220. I hung out at the store for a while; made a few phone calls; then went down the road to Andover hunt/fish and browsed around. When I got back to Simon-Peter the NICS had gone through.
Both were on the weekend and both went through in about an hour.