two things Sir...
I keep #4 in the defender, opinions on shotsize???
I used to keep it loaded and locked, but figured the spring would ultimately get fatigued...or do you alternate the twins and give em 'off' days ???
oopsie, meant to get opinions from you gents as well...
I bought some 00 tactical buckshot. It's has less recoil than standard buckshot and is easier to get the second round off in a hurry. A lot of police forces are using it because it does a great job with less chance of penetrating walls.
#4 hardened shot has good cross-sectional area, but does not "reliably" penetrate (only 7 to 10") to depths that inflict enough damage on the target to be considered lethal, though I still wouldn't want to be on the receiving end. My guess is that you are concerned with wall penetration as well. #4 will certainly get someone's attention, but if you don't want them to get back up again use #1.
The only twins I alternate are my wife's ;~).
Seriously though I haven't seen, or experienced anything that would lead me to believe that keeping a round chambered for a long period of time is detrimental to the operation of a weapon, but that does not account for the age of the weapon and any design or material flaws.
In all honesty, I change the ammo out in my weapons on a regular basis, by firing them. There is no excuse for not training with a weapon that you intend to use to save your life, should the need arise.
Gilbo! :-) All I know is what my son tells me about his Mossberg 500. I don’t have a shotgun, and really don’t know much about them. He leaves his with a “full stack” in the tube magazine, with NO round in the chamber, with the hammer FORWARD. He also keeps five or six rounds on a “side saddle” ammo holder attached to the left side of the receiver. He was telling me though that eventually, the magazine spring will become compressed from leaving it loaded, and he’s in the process of getting some spares now. I told him just to pull it out and “stretch” it, and he didn’t seem to be pleased with my answer. :-) I’m not sure what he keeps it loaded with, but it kicks like a mule! They’re high brass shells and have 18 pellets....rather LARGE ones. I can use it, and do sometimes shoot it with him, but it tries to remove my arm from my shoulder! He’s a big man though and it doesn’t bother him. :-)
Two in the mag and a side-saddle...good to go, even if you don't have time to grab a couple three rounds from the box that should already be at hand.