John Browning stopped working on a 20 gauge version before WWI. The reason being that he couldn’t make it lighter than the more effective 16. To him, the whole point of a smaller shell is a lighter gun. When Germany occupied Belgium in 1940, Remington supplied guns to Browning. Really a Model 11 with a magazine cutoff and pseudo-Browning engraving. But it was offered in 20 gauge. FN-Browning got around to offering a 20 gauge version in 1958. These guns were based on the 16, and were dubbed the Light Twenty, as they used the same lightening techniques as the Sweet Sixteen. There has been a lot of confusion over the name, as until 1973 just TWENTY was written in script on the receiver. That year the full name was applied. So, all 20’s are Light Twenty’s. There never was a standard-weight. When JMB designed the 16, he didn’t just scale down the receiver, he shortened it. So on the 16 and 20, part of the barrel extension pokes out of the receiver. The previously mentioned advice about it poking out too far still applies. In this case look for an un-blued crescent of silver.