Diana made 34's in .20 back in the day then quit, although way before my time so no idea why. Gentleman named Hector Medina got the idea to set up a group buy and have 30 each of the 34's and 54's only with L-W blanks made to his specs. The 34's were built first, back around 2006 or so and I got mine all these years later after several buyers dropped out, he had to buy several himself to guarantee 30 and they ended up on a shelf.
The R7 .20 I have is Huntington Beach Era, and built in 2005. Appears to have never been opened up since I went over every inch and couldn't find a single mark anywhere. Numbers I got over my chrony with FTT's and the JSB 13.73gr:
-H&N FTT's: Average 554, ES 11, SD 3, 7.78 fpe
-JSB Exact: Average 497, ES 20, SD 6, 7.53 fpe
I only use it out to the 30ish yards I have for a backyard, but it's easily taken squirrels that far out and if I do my part, both pellets easily shoot under dimed sized groups.