Thanks to all, sorry to bring this up again but I still didn't have a satisfactory answer to the proper method of patterning a .410 gun.
I tried using a 30" circle at 25 yards but the results were useless because every pattern I shot would be a full choke, even though they were very ragged and uneven.
Jack O'Connor did say That the gun was patterned with a 30" circle at 25 yards, a few pages later He says that it should be 30 yards.
I think I finally found the answer, Don Zutz writing in " A Practical Approach to Patterning" says that the .410 is patterned using a 20" circle at 25 yards.
Pete