Unfortunately Jimbo, they are no public rifle/pistol outdoor ranges in Lincoln. As you already pointed out, Lincoln Trap an Skeet on North 48th st is open to the public, but no rifle or pistol allowed there.
They do have Trap, Skeet, and 5 stand Sporting Clays
Lincoln Parks and Recreation may be building an indoor archery range(25 yards) that will probably incorporate rimfire pistol lanes some time in the near future.
And, there is the Seasons Choice indoor range at 48th & Hartley.
Rumors have another indoor range in planning , but so far it ain't happening.
I finally joined the Lincoln Izaak Walton League this year, and I am finding well worth the money