What a Difference Bullet Weight Makes!

[Oscar77]

If you are curious, take a tight fitting bore brush with a rotating rod (like say a dewey) and run it down the bore.
Take note of the revolutions and how long it took and you will find your twist..........

PS: It looks old, so look all the way around the barrel (not just on top where they usually are marked) and back to under the FSB...........
You might just see a "12" ............. I doubt that is so old, it's a "14."