500k potentiometer question

[meltingfaces]

I'm currently in the process of gutting out an epiphone prophecy em-2 for all new electronics and I stumbled upon an issue I never considered before. The mounting holes for the 2 pots are 5/16" which is just too small to fit the 3/8" pots I already bought. I've searched high and low and it seems the 5/16" pots are much less common - any reason for this?

[paulster]

Epiphones use metric pots (and hardware) rather than imperial, so you just need to ream out the mounting holes slightly. I had to do this when I upgraded the wiring on a pal's Epi Les Paul and the new pots wouldn't drop straight in. It does, of course, mean that you have to replace the knobs with imperial ones too.

A tapered hand reamer is perfect for the job as a couple of turns is all it takes.

[DanO]

Epiphones use metric pots (and hardware) rather than imperial, so you just need to ream out the mounting holes slightly. I had to do this when I upgraded the wiring on a pal's Epi Les Paul and the new pots wouldn't drop straight in. It does, of course, mean that you have to replace the knobs with imperial ones too.

A tapered hand reamer is perfect for the job as a couple of turns is all it takes.

Paulster's got it right---a hand reamer is definitely the way to do it; using a drill bit/drill is inviting chipping and splitting around the hole. Don't ask me how I know

Interestingly, the pot shafts are often (not always) the same size, so knobs will fit either/both.

[908ssp]

Epiphones use metric pots (and hardware) rather than imperial, so you just need to ream out the mounting holes slightly. I had to do this when I upgraded the wiring on a pal's Epi Les Paul and the new pots wouldn't drop straight in. It does, of course, mean that you have to replace the knobs with imperial ones too.

A tapered hand reamer is perfect for the job as a couple of turns is all it takes.

Paulster's got it right---a hand reamer is definitely the way to do it; using a drill bit/drill is inviting chipping and splitting around the hole. Don't ask me how I know

Interestingly, the pot shafts are often (not always) the same size, so knobs will fit either/both.

Yup what they said.