What range did you finally decide on? Please consider posting an after-action report on your training when you get done- it can be helpful.
Re. #1 buckshot, keep an eye on the thread at
http://www.thehighroad.org/showthread.php?t=295587 . Maybe someone there will share their sources for it. Usually #4 buck is pretty common, it's a more popular load in most places.
I tried the Knoxx SpecOps stock on one of the 870s here, hoping it might prove useful for my wife. We both disliked it though, she because she didn't care for the pistol grip style stock, I because the 'tube' was too fat and I couldn't get a proper cheek weld with it. Truth to tell, I do in fact have chubby cheeks, but that doesn't prove a problem for me getting a cheek weld with a conventional stock. After just one range session, I took it off and went back to the conventional stock.
You may find that any form of pistol grip stock causes some issues with access to the safety on a Mossberg 500. You have to break your firing grip in order to manipulate the safety when you put a PG stock on a 500. I find it ironic that many shotgunners so strongly tout the "inherent superiority" of the Mossberg's top tang safety, and then put on a pistol grip style stock which effectively places the safety out of reach without breaking the firing grip.
Stock length IS a major consideration, a defensive shotgun which will be used by more than one shooter should be fitted to the smallest shooter who will be using it. It is much much easier to effectively use a shotgun with a too-short stock than one with a stock too long for the shooter. All you have to do is to remember to place the thumb of the shooting hand over on the knuckle of the trigger finger (assuming a conventional style stock). Otherwise it's likely that recoil-induced contact of thumb and nose will remind you that you forgot something. 8^)
My wife (in her early 60s, 5'4" and 130 pounds) is perfectly comfortable shooting a 12 gauge 870 that fits her properly with full house slug and buckshot loads. Our 'house guns' have 12.5" length of pull conventional style stocks, fitted with premium recoil pads. They have full size 'field length' forearms (9" long, compared to the 7" police style forearm that Remington uses on some guns) so that she can reach the forearm easier without having to over-extend her support arm.
There are no magazine extensions on these guns, just 18" or 20" barrels with rifle sights. I tried an extension for her and it's just too much weight out in front of the support hand for her to manage easily- so off it came. Weaponlights are rail-mounted Streamlight M-3s or LEDWave Z-5s that weigh mere ounces and fit on ring-mounted rails that go under the magazine cap. And each has a 4-round Sidesaddle on the receiver.
Interesting thing is that after some use and experience, I can handle these shorties (with an 18" barrel they run a fraction over 37" long overall) just fine too- and I'm 6'3" and wear a 37" sleeve. In fact I have come to prefer a short stock on a shotgun over the "normal" factory stock length after several years of working with them.
FWIW,
lpl/nc
