Which again, begs the question…if you do have no plan for escape…why not bring your pistol? Why in the world would you purposely set it up to where you have to go home and get your gun if you have no escape plan?
Long before the assassination Oswald was living in Dallas at a boarding house. His wife was living in Irving Texas at the home of her best friend Ruth Payne. Oswald visited the Payne residence on weekends to see his family. HE also stored his rifle in Ruth Payne's garage wrapped in a blanket. A pistol is easy to hide in a drawer or under a bed but a rifle not so much. The point is he routinely stored them separately for whatever reason.
The Motorcade route was announced on a days or a few days before the actual arrival of kennedy depending on which newspaper one read. Oswald was in the habit of reading old newspapers he found lying on the floor of the break room of the texas TSBD.
In all likelyhood he decided to make his move and try to kill Kennedy on Thursday November 21st which was one day before the shooting. This is reinforced by the fact that we have many witnesses testifying to odd changes in his behavior the day before the shooting. He visited Ruth Payne's house that night which was a weeknight and something he had never done before. Obviously to retrieve the rifle. Which he did.
HE had no chance to retrieve the pistol because he had to bum a ride from a co worker named Wesley Frazier to get to Irving Texas. Frazier lived very close to the Payne residence and did not mind driving OSwald to Irving and back to work the next day but he probably would not have wanted to drive all over Dallas to help Oswald run errands.
Oswald's trip to Irving with Frazier was clearly a last minute thing instead of something thought out in advance and obviously he could have had Frazier swing by the boarding house before work on Friday. This would ruin his plan to smuggle in the rifle which was wrapped in a paper bag and which he claimed was curtain rods for his boarding house room.
When one considers all of these details it makes sense. HE could access one or the other weapon the day before the shooting which is when he probably planned try for the shooting of Kennedy. Obviously the rifle was the most important piece of that plan and he retrieved the pistol only when he got very lucky and managed to slip out.