I have an old System 1, with both a 12 and a 50 cal. Never could get a load I liked out of the 12 gauge and have missed 2 birds with it. It was a 25 yard gun and i should be able to do better. Messed around with a choke I had and it was not good. Did not really fit the gun.
I decided today to head to Whigham and Trulock Chokes. Great decision. The lady tried to fit it, it was obviously the Win/Moss/browning choke but it was not quite right. She took it in back and a young fellow came out with his micrometer. The knurl was hitting the barrel end before the choke throat fully engaged the barrel by the tiniest bit. He said he could shave off the knurl just a bit and so I figured he would do it later and send me the choke. He said, nah, it will just take a minute. Sure enough, he got me on my way in a very short time.
Now with the proper choke, it was time to pattern. I played around and could not get what I was happy with for a few loads, but finally hit paydirt. In the other threads, I was worried about penetration, so I saw I had a can of Crab meat that was well out of date. Perfect test media! After getting it sighted in and adjusting the red dot, I let this load fly at 38 steps (I knew it was over 35 and it measured just a bit over 38 yards). I will post the pics from my phone.