Hey Marty,
I have fired those darts from my old Marksman air pistol, and had a lot of fun with them !
I have also used then to discourage some pests, hoping to encourage them to move on ! It didn't work very often :0
These darts are not recomended for air guns with rifling, as they are made of hard steel and will damage the rifling !
The 1377 is rifled, so I wouldn't use them too often ! But you can still find the Marksman pistol at reasonable prices, with a target and darts !!!!
Bill