I too had my own personal B-20 late production (serial numbers greater than 0300xxxxxxx) and what a great gun it was. Gene only had to shoot it one time and then there was no doubt in his mind. He wanted to buy it but I turned him down. It took awhile for him to find one but he did and it is a real winner and will probably never let it go.
I swore that I would never let mine go either but eventually I sold it. One day a customer came by to pick up a gun I had tuned for him and we were talking about the B-26 and I told him the history behind it. He asked if he could shoot my B-20 and of course I said yes. He put about twenty rounds through it and didn't want to give it back. I just couldn't turn down his eventual offer, especially since I don't shoot much anymore.
The early B-20's with the 0200xxxxx serial numbers for the most part were not all that good and some were actually dangerous but the late production B-20's were a real good gun and excellent once tuned. In the early days when I was doing the "Sales Project", I probably sold 200 or more, some tuned and some not tuned.
Later, there was a big mix of the early and late B-20's being sold and the "Bad" reputation although based on the early model was killing sales and was the main reasoning behind the change to B-26 along with a bit of cosmetic change. I would order a case of 5, make two good ones out of the 5 and send 3 back to John.
The B-21 had a pretty harsh reputation. Some of you old timers may remember them being affectionately called "The Beast". I believe I was the one that coined that name and hung it on it but it was also referred to as the Scope Killer, Arm Buster, My Dentists Friend and a couple of others as well. I used to order those by the case also and as a joke, offered an optional wagon to drag the B-21 around with
. It suffered the same demise as the B-20, and was later upgraded a little and became the B-30.
Boy how some of the Chinese airgun products have changed, especially in the BAM line. Tremendous improvements and much better quality in the last few years. They don't compare to the German or English guns but vastly improved.
As others have stated, the B-26, which replaced the B-20 series is one of the best values out there. MikeinIowa and I go back quite a few years. The deals that he throws out there are hard to beat whether is in Co2's or springers you can be rest assured that if you purchase a gun from Mike, you will have a good one .... but sometimes crap happen.
If it does... Mike makes it right as anybody that is on this forum will attest to.