My 870 measured 48 inches overall; the Model 500 was half an inch shorter. The 870 weighed 7 pounds, 11 ounces; the 500 came in at 7 pounds, 2 ounces. The half-pound-plus difference in weight is largely due to the fact that the 870 has a steel receiver, while the Model 500 receiver is aluminum alloy. The Mossberg does have a heavier barrel than the 870, and the result is that it has a much more weight-forward balance than does the 870, despite being lighter overall. The choice depends on both personal preference and on use. Upland-bird hunters like light guns that are easy to carry, while waterfowlers and target shooters, who don’t have to walk much, prefer heavier, steadier guns that swing smoothly.