Don't have specific information, but playing with a 38-35 lately. Case is 1.68" long, 290 grain bullet, breech seated. Started with 16 grains of 4227, ended up with 18 grains. Would guess 35-30 at three or four grains less. Maybe start at about 32-40 level and carefully increase.
Chuck

It's a very old thread, but did you ever make any headway with your .35-30 Maynard?  I just bought one and the previous owner was shooting 200 grain bullets over 12.5 grains of SR4759.  I haven't had a chance to shoot this one yet ... we're up to our buns in snow right now!

I will likely delve into some duplex loads in my Maynards with a light "kicker" charge of either SR4759, IMR4227, or maybe even with some very old Dupont Bulk Shotgun powder that I have a couple of pounds of and then I'll load the balance of the case with black powder.  There wasn't a mould with the rifle, but there are some sample Maynard bullets and I know that Accurate makes some moulds in the original Maynard designs so I'll look into them for this .35 and my three .40's.  I wish I could find a paper patch mould suitable for my .32-35 Maynard, but I might have to try altering an existing mould to make something suitable for it.  (Maybe a 7mm mould bored out into a smooth sided .300" paper patch bullet of about 153 to 160 grains.)

OK, thanks!  I also realized to today that I have the old Ideal / Lyman mould for a 145 grain .375" cast bullet that was for use as a gallery bullet in .38-55's.  Since I already have the mould and a few of the bullets cast I could try that first.  Still have to slug the barrels on all of these Maynards to see what bore sizes I'm working with.  I've found reference material online that says the .35-30 Maynard SHOULD have a grove size of about .370" to .375" with most of the bullets designed for it dropping out of their moulds at about .375".  Sound about right?  Again, I'll slug it and go from there.

OK.  Again, I already have some of these old Ideal 145 grainers cast, lubed, and sized at .375" from memory and I can always reduce them in diameter to suit the actual slugged bore size.
Don't know how successful it'll be, but I bought a cheap ($10) used set of steel (non-carbide) .38/.357 dies just to get the sizer.  I'm going to see if my machinist buddy can ream / bore / polish the sizer die up to about .408" to .410" as an intermediate sizing / swaging die to bring the bases of the donor .30-30 cases down about 1/2 way to the .403" that is needed.  I lucked into a set of CH4D dies for my .32-35 Maynard and I hope I can finish them up in the full length sizer and bring them the rest of the way down to .403" at the base.  Then I'll shorten the cases to the required length, add the rim adaptors, and then fire-form them into .35-30's.  At least that's the plan at the moment ...