I just installed a Dave's Metal Works full length magazine tube on my Benelli M4 and wanted to recommend this to anyone considering the 7 round tube vs. the 2 shot extension. If you are concerned about removing the factory magazine tube relax. I stripped the gun and clamped the receiver in a padded vise. The magazine tube was too tight to unscrew without heat. I applied some heat to the receiver with a heat gun and it took less than a minute to get warm enough to turn the magazine by hand. It took so little heat to loosen the loctite on the magazine threads that I could easily and comfortably turn the tube with my bare hand. It took very little heat and I'd estimate the receiver never got hotter than 200 degrees. That's too low to hurt anything including the anodized finish on the receiver. So if the thought of applying heat to your receiver freaks you out, relax. Its no big deal. I also highly recommend the Dave's Metal Works tube. Its less than half the price of its titanium competitor and it matches the phosphate finish on the barrel perfectly.