MAX 1/4-Inch Staples for HD-3DF Stapler, 1,000 Staples Per Box (3-1M)

I recently purchased an HD-3DF stapler and purchased these staples and the 3/8" size. These staples fail to feed properly and the stapler just "dry staples". I switched to the No3-10 staples (the 3/8" size) and things worked perfectly. I tried loading a single stick and two sticks with the same results. Use the No3-10 and the stapler is flawless. Use the No3-1M and it's a paperweight.

They're staples, they work for the heavy duty stapler we have in the office, not much else can be said.