Mounting same size boots?

I guess it's dependent on the BSL of the boots. Are you thinking of sharing a pair of skis or something?

If they are the same size yes. If I wear a size 10 Nike shoe will I fit into my friend's size 10 Nike shoe? yes

TDD536I guess it's dependent on the BSL of the boots. Are you thinking of sharing a pair of skis or something?

this^^^
bsl (boot sole length) is the length of the plastic bottom in mm. The size of the boot has nothing to do with it. Usually the length is on the bottom of the boot.

On the side of the boot there will be a mm sole length molded into the boot. If they have the same number you are good to go. I have several boots, all the same mondo size yet all different BSL. so adjustment is needed for the different boots.

Full Tilts run about 10mm smaller than most other brands BSLs. If your going Full Tilt to Full Tilt (same Mondo) you'll be okay. But If go from a FT to a Salomon, Dalbello, Nordica, ect.. there will have to be a forward pressure adjustment. Most binding brands can move up 10mm-15mm, less for moving shorter. Exception is FKS's and Pivots where there is only 5mm of adjustment. When in doubt have a tech check it out! #supportyourlocalskishop

The boot sole length has to be within like 2 mm because if its off it won't fit into the binding at all and/or the forward pressure won't be correct.