Got new style poly mags, they are light might even be lighter that P-mags.Slipped in mag well clicked and held..tight tried again would not engage neither one would engage.RRA sent a card Note: Due to progressive enhancements to the RRA LAR-8rifle,some LAR-8s may require the LAR-8 poly mag be modified slightly by the end user for proper fit/function in his/her rifle as shown in the diasgram to the right. Due to the difference in the cartridge dimensions between the .308/7.62X51 NATO round and the .243 and 7mm-08,these alternate caliber uppers must be used with RRA's polymer LAR-8 mag. and not with FAL/L1A1 mag.It took a slight filing with a fine tooth file @ A&B and mag engaged without problem and seated snug no wiggle.The metal mag next to it is a RRA mag seated snug with a light wiggel.The use Fn-Fal mags I had were the wiggeliest <lmao> with the new wolff springs function as expected.Included are different views of mags poly & metal both RRA.FYI for you RRA fans <thumbsup>