I found a little more info on the 1906 trials cartridge in Handloader #265 from April 2010. Dave Scovill wrote on page 8 "The Saga of R.S.Q." He also addressed the 1909 cartridge, the length of the .44spl case in relation to bulky smokless powders, says the rimless version is nearly identical to the Webley Fosbery case, loaded with 6.9gr of R.S.Q. and mentions there is a photo of a Colt New Service Model 1907 chambered in the experimental cartridge in a book published in 2009. Seems to me the 06 cartridge has a lot in common with the various Webley ctgs. The rim is only .03 thicker than the .455. Just a little more info on this topic, not much, I'm afraid.......

__________________
dd884
JMHO-YMMV