Didn't follow the instructions the first time... my bad.. After that though it printed fine and works great!
Word to the wise, PLA is brittle, and seems more so in cold weather.
I did not print it, yet.
Glad I found this, easy print and came out perfect no changes, ender 3 printed with PLA 15 percent infill,
Works great and is a great addition for competition shooting.
Awesome product. Thank you for taking the time to create this file that anyone with a 3D printer can make. Best of all, it's free.