If you want to shoot groups with more rounds for accuracy testing, you should let the gun cool between rounds fired. As a barrel heats up it will "walk" and your groups won't be real world first shot accuracy representative.
Unless there is a problem with the gun,the groups will not "walk".In fact,I shoot my three shot,and five shot groups,one shot after the other then let the barrel cool between groups.By shooting the three or five shots one after the other,I can see if there is a problem with the gun,such as bedding.