Iver johnson s CHAMPION single barrel shotgun ? GA

Question
QUESTION: A friend gave me a shotgun years ago (probably because I'm such a handsom fellow).  I believe it is a 1901 Champion single barrel shotgun but I understand it could be a 4.10, a 12 GA,a 16 GA,or a 20 GA.  I'm no expert on these weapons. I only know the M-14 and the AK-47.  Both those weapons and and a .45 got me through 3 one year tours and I was only seriously wounded once.  I will give you all the information I have and I would seriously be grateful if you could me with as muchj information as you can about my shotgun.The left side of th triger housing there is a stamp that says Iver Johnson's
ARMS AND CYCLE WORKS
FITCHBURG MASS.USA
The top rear of the barrel is stamped: CHAMPION and PATD APR 8'01 AND APR  15'O2 PAT PENDING and on the bottom of the barrel is 62224. I thank you in advance for your help, KAK/RN. advavc

ANSWER: Hi,
These were made from 1909 to 1956.
These were utility grade guns.
A base model with one barrel is worth $25 to $175 depending on condition.
Add $25 if it has a vent rib.
Trap models are collectable and cand can be worth $450

http://iverjohnsoncollector.x10hosting.com/
http://oldguns.net/faq.htm

---------- FOLLOW-UP ----------

QUESTION: If PATD APR 2'O1 does not mean the gun was made in 1901,then how do I determine the ace of the gun?  Do you know how I can determine the gauge of the  gun?  Once again I would Like to thank you in advance for any and all the attention you may give this matter.
Sincerely,
KAK/RN

Answer
The model was not introduced till 1909.
The pat. date was when a feature was approved for PAT in 1901.
It was likily developed for a earlier model.
This is not uncommon.
I had a Colt with a patient date 1836.
It was made in the 1994.
You can only exactly date it if there is public database of serial number.
There is none for Iver Johnson.
Plus serial numbers were not required untill 1968.
Many times utility grade guns can not be dated.

Any gun store should be able to determine its gauge with one of these.
http://www.shotgunsportsmagazine.com/store/index.php?main_page=product_info&prod
While there have them check the chamber.
Make sure it has 2.75 inch chamber.