Has any one found that the very bottom of a tin to be much less pleasant ? 

Do you scrape the bottom to get every last MG of snuff ? Or do you toss it well before that.

Is there any danger of the snuff that is stuck to the very bottom being ruined by the metal of the tin ?

i usually just tap the tin out, some old mill snuff I’d sort of wipe the bottom out but I’ve never scraped it out. If the snuff is that stuck or crystallized I’d likely just leave it in there

No I decant into glass jars. I dump all the snuff on to a piece of paper I had previous folded in half now opened and tap out the dust.{ one should always open full tins over a piece of paper to avoid spillage} Then I gravity fill the jars by bringing the two outer edges together .Lifting one end, the snuff slides effortlessly into the jar like a shoot to be visited at the time of my choosing. I will then place a usable amount about a day or two worth into one of many snuffboxes I enjoy. All my snuff has stayed as fresh as day one.

Well, I have a confession: In private, after a good meal, I’m a plate licker. If it’s a nice meal there’s no way I’m going to waste that last little bit, and I’m the same with my snuff tins - finger goes round the inside edge of the tins, and along the base. 

I paid for it, I enjoyed it, and I’m going to savour every last bit of it!

scraping the bottom of my Elmo’s Reserve tin right now. I did mix it with alittle fresh KB Plain to try to stretch it though just finished the last of it. I only do this with certain snuffs though with everything else when I get down to those crumbs you cant pinch out I just mix them all up into a jar of leftovers.

*Edit

Forgot to answer your question, I do find the crumbs are not as nice as the fresh stuff, though the snuffs I love I still love when they’re a little dried out.

Like the Shamen, I tend to use snuff from snuffboxes, or recycled 10g Toque tins. This minimises air exposure to the main tin/jar. I do find it can still deteriorate, but should this happen I will rehydrate a snuffbox overnight, and this wakes the snuff back up. If a tin goes rusty, I abort and throw it out. My moist snuffs which are prone to this are generally transferred to glass.