In response to a posting by Fortkevin2, about the deference in felt recoil between slugs and bird shot, I opined that #7 shot is fairly rare, and most folks use #7-1/2. Now we know why #7 is used so infrequently: Sniperinky's report on spread with #7 shot explains its limited use -- most folks are looking for a little more pattern development than sniperinky experiences.
Not to worry about your 11-87 running our of gas with an extended magazine tube. The 11-87, like all gas operated auto-loaders, gets it's gas from the shells it fires. Just be careful, and stick to standard ammo. Don't get any ammo marked "gas free" or "reduced gas" even if it's deeply discounted just before hunting season. It's intended for pumps, inertia auto-loaders and break-open guns and will really mess up an 11-87 or other gas gun. Excessive muzzle deposits can result in messy clean-ups. If you're going to be shooting off your gas gun, you need to pay attention to what you feed it; otherwise, you may experience little muffled pops instead of full-power blasts. Also, the "gas free" and "reduced gas" ammo require some special procedures when reloading.
Yep, your 11-87 would make a great avatar, unfortunately this site doesn't support them.
LOL, Pete