Im sure this will open up a can of worms/opinions- but a good carbine with proper ammunition is the best overall choice for HD for TONS of reasons. Go read Dr. Roberts write up of why. Docgkr on light fighter.
I can agree it is a good weapon for HD...best...not so sure. I am looking at HD as real distances of 10-20 feet max. Obviously you have lots of experience with different guns. Just putting out a counter point of a semi auto shotgun with mag extension.
I give you the carbine round is deadly....but don't you think putting bullets into your target is the most important thing. I agree the shotgun is going to have a lot more recoil per shot....but it is also putting out a lot more projectiles in a wider pattern.
Open to info...and hearing a different perspective.[/QUOTE]
Various reasons why multiple projectiles are not ideal for HD- collateral
Damage being front and center.
Do you live in an ur an area? Have kids or a spouse in the house, or pets?
Multiple projectiles are not ideal in the above scenarios. If you are alone on a ranch with 100 acres, that can change. But still a shotgun and handguns are not ideal when compared to carbine with proper ammunition selections in MOST scenarios.
We have the issue of over penetration. You'd think a handgun round or shotgun round would penetrate less than a .223 rem of 5.56 NATO round, but this is not the case.
A common concern for people when trying to decide which caliber to choose for self defense is overpenetration inside the home. Many believe that pistols calibers would automatically penetrate less than rifle bullets, or that light fragmenting bullets will allow you to not be concerned with overpenetration. In regards to the latter - this is a false assumption. Take, for example, the Glaser Safety Slug. It is a pre-fragmented bullet with very shallow and completely penetration in bare gelatin. When fired through drywall, the bullet fails to expand and behaves as a FMJ solid. Another example would be using a lightweight varmint bullet in an AR, thinking that the shallow penetration in tissue would be sufficient to not worry about persons in adjacent rooms in case of a miss. The question I would ask is this: If you knew that there is a person in a room behind the bad guy and you're only separated by drywall, would you really risk taking a shot and rely solely on the bullet to not hurt or kill someone in case of a miss?
As far as the idea that pistol bullets will inherently penetrate less than rifle cartridges, take a look at this graph comparing common weapons one might employ in the role of self-defense:
Notice that the penetration of all these calibers using high-quality ammunition is approximately the same, quite contrary to common belief. The reason pistol calibers penetrate quite deeply is, as has been mentioned before, the fact that momentum is the key factor here. The slower, heavier bullets retain more momentum and can thus penetrate as much as a bullet launched at much higher velocity. Bullet construction obviously plays a key role as well.
The situation won't change very much if drywall is introduced into the equation:
There is not much that has to be said about this picture; the .223 calibers rapidly lose their momentum after penetrating drywall first, while the heavier bullets do not. Note that the pistol calibers in the example above penetrate to approximately 50cm (~20"). That would lead me to believe that the bullets chosen for that test didn't expand and thus further highlights the need to choose ammunition which passes the FBI test protocols. A Winchester Ranger-T bullet penetrates approximately 15" (~38cm) after encountering wallboard - about the same as the .308 155gr AMAX.
So again collateral damage becomes an issue.
Now let's talk capacity. Shotguns, most anyways are limited to
Around 8 rounds. Yes, some can take and some less, but let's use 8. Most handguns are 15-17 rounds for 9mm.
An ar15 can take a 30 or 40 round and greater capacity magazines.
Looking at FBI data on real world shootings and gun fights, calibers rarely ever matter the most, it's most hits on target.
So let's think about that. The data reveals that a greater amount of hits on target is what put down an assailant. Not the caliber. There are tons of fun fights with multiple .357 mag, multiple .44 mag hits, multiple .45 ACP hits or multiple 00 hits and the assailant won't go down, be it drugs or just being a part of that small percentage of folks who do not give up until bled out- capacity matters. Big time.
So again the capacity of a carbine is king.
The capacity along with the more desireable level of penetration and not under or over penetrating along with ease of use gives it the nod as best for HD in MOST cases.
I have tons more info to provide, but need to get some shit done so inwill edit my post and add more later.
Here's the full write up by Doctor Gary Roberts, the foremost authority on the topic:
http://www.firearmstactical.com/
Here's another link to arfcom with a good deal of data on proper ammunition selection by caliber- it's mostly the same data from the first link also:
http://www.ar15.com/ammo/project/Self_Defense_Ammo_FAQ/
Dr Roberts on light fighter :
http://www.lightfighter.net/topic/home-defense-long-guns
People often say "if X number of rounds of X caliber doesn't get the job done, then nothing will..." that simply isn't true when looking at real world data.
Sometimes it takes many, many rounds of various calibers to stop the threat, sometimes a single .25 ACP placed properly gets it done. No situation is the same. So we must prepare for the worst and hope for The best when selecting an HD firearm and ammunition.
All of that being said- choose what's best for you and your specific needs/area/situation. What you are most familiar with, have the highest degree of training with, and are most proficient with. And- PLEASE choose high quality ammunition that passes FBI tests/protocols.