That's one of the coins I thought it might be, but it doesn't have the correct mintmark. I managed to find this one, but the size and weight don't match: https://en.numista.com/catalogue/pieces33926.html
Yes, Ottoman struck in Constantinople/Istambul, but would it not rather be this one?
"26" is the regnal year. 1223 = 1st regnal year; 1248 = 26th regnal year.
EDIT: Maybe the coin I linked to is too heavy.
And I see Zoinsy replied in the meantime.
That definitely looks like it could be it. Given that it doesn't seem to be a milled coin, there may be a fair amount of difference in weight between individual coins.
There's also the fact that it has very low silver content and it, like yours, looks copper more than silver. I wonder whether it should be called "billon" in the catalogue.
Quote: "Camerinvs" I wonder whether it should be called "billon" in the catalogue.
I think the term "billon" is used for coins with low silver content but with no records/data of the exact amount of silver which was used when they were produced. Or when the silver content differs from batch to batch.
Otherwise this coin definitely would be called "billon": https://en.numista.com/catalogue/pieces3550.html
