Absolutely foolish to use anything but an arrow saw.
Not everything can be a DYI. I'm a fan of ******* engineering when I can, but there are many things that require the right tool for the job.....this is one of them.
Besides losing any bit of precision, the only thing that keeps it from being completely unsafe is it's at the point end.
Do yourself a favor and find someone with an arrow saw. Better yet, make the investment....it will last a lifetime for a home user.