I own a 280 Ross M1910. I've purchased appropriately sized bullets from Hawk and Quality Cartridge. I am familiar with drawing bullets down from .323 to .318 for my Mauser but I have no experience trying to bump up jacketed bullets for this rifle.
Is it possible to do in a relatively economical way? I looked at Corbin but cost looked high. I would be willing to try and make my own die but I'm not a machinist.

not really.
plus running a bullet into a PF die not the same ogive shape is a pretty good way to get one stuck.

all you need to make a die is a die body a and a cutter.
and some measuring-machining skill.

you'll also want to make a punch while your there.

if you can do that you might as well make a core seat die, a core swage die, a core mold, a jacket draw die [so you can use 30 cal jackets] and a pinch-trim die [to make them the proper length]
those are all about 10 times easier to make than a Point Form die.

Ive made a core swage and a core seater dies, but point form dies are the most sophisticated to make. For those I order from Corbin. They are also the most important to get right. If the point form die is not a precision die you will end up with bogus bullets. Otherwise going from .284 to .287 should be doable with the right equipment. Not very economical though.

What velocities are you looking at? Ive never heard of anyone powder coating jacketed bullets, but there is a first time for everything. Just a thought. .003" aint very much.

Why don’t you just shoot 284 bullets and see what happens?

I use 243 bullets in my 244 H&H magnum that uses 245 bullets.

Only difference is change in the POI.

I have been shooting some 145 gr .284 bullets but accuracy was not as good as my .287 Quality Cartridge monolithics. Ijust bought a box of 160 gr .284's and I will see if a heavier bullet performs better. Thanks to all for their comments.

My bet is that Hammer Bullets would make some off-diameter bullets for you. (I won't bet much. haha)

Zeke