From everything I have read over the last several years. The factory 35 Remington loadings from the big three at least of Remington, Winchester and Federal are all underloaded to even the current SAAMI spec. This is because of older Remington model 8 (I think) and other pump guns that were chambered in 35Rem. These actions are weaker than say a modern Marlin 336.
The exact same 336 action in a 30-30 is I believe 42,000. Also the 336ER in 356 win Marlin produced also used the exact same receiver. There are many myths that the 336 ER was a different receiver with heat treating etc but as far as I've been able to research there is absolutely no proof what so ever that it is any different than any other 336 receiver.
So while it is true that extrapolating data is not necessarily 100% accurate. It is also true that in modern Marlin 336 actions there is sufficient strength in the action to go above the 35 Rem factory SAAMI spec. There are people on other forums that are in fact doing pressure testing on the 35 rem. The testing so far proves that the factory rounds are well under the SAAMI spec even for an "underloaded" 35 Rem.
Check out marlinoweners and beartooth bullet forums. There is a wealth of information there. And there are many many people out there that seem to be loading the 35 Rem to 2200 fps and have been doing so for many years.
