I just bought a brand new Remington 870 Tactical 7 shot 18.5" cylinder bore bead sight shotgun for home defense, and just shooting in general.
My first couple of shots with the gun I noticed the racking of the gun was really hard... I shot about 20 rounds though it, then cleaned it and lubed the heck out of the action, slide, and all other moving parts. I went to shoot it a few more times, and I had a couple shells where the rim ripped partly off the case as I tried to get the gun to extract the shell. And these were just standard Remington no. 8 bird shot rounds. I put about 10 Federal Tru-ball 1oz slugs though the gun, and it extracted them a little better. Total shot count thought the gun right now is about 60 rounds (50 of bird shot, and 10 slugs).
For a comparison I shot my 870 express I bought used, and that one worked just perfect. Do 870 need a "break in" period? Or does Remington no. 8 shot just that cheap? Next 100 round bulk pack I buy for breaking clays will be Federal. Never had issues with Federal.