Unusable junk - ProMag Ruger SR9 10 Round 9mm Luger Pistol Magazine

I bought these because they were cheap and wanted a full size magazine to use with my magazine extenders on my Ruger SR9C. When fully loaded with 10 Rounds it is nearly impossible to charge the weapon. The slide mechanism drags on the first round because there was not enough give in the Magazine spring to allowed it to slide back smoothly. Once the first round has been cleared or you only load 9 rounds in the mag it operates smoothly. But because of the 10-round limitation sometimes the spring gets caught on The dimple in the magazine which only allows you to load 10 Rounds and the last round does not get fed properly.