This is a discussion on Best Choice-12 ga. 00 Buck-,9 or 12 pellets? within the Defensive Rifles & Shotgun Discussion forums, part of the Related Topics category; Originally Posted by ccw9mm If you pattern it through a battery of various rounds and document the trends, then selection won't simply be based on ...
Home Defense Shotgun Ammo. Here is also a good discussion from earlier in the year, on DefensiveCarry: click. Or, others: Box O' Truth, discussion from last year. As well, there are discussions from time to time in which some of the LEO's here have related their Departments' experiences in shell selection.
It's great that your shotgun "eats" everything. That answers the reliability question, perhaps.
IMO, what you need to understand are the following:
- What is your gun's specific pattern, for a given load, at specific distances?
- How does that compare to different loads at the same distances?
- What are the energy values of shot delivered on target, for the different loads.
- How likely are you to get a given percentage of shot on target, based on recoil, blast, etc.?
- What shell is the most reliable in your specific gun? Yours seems to eat everything, which is good. One item off the list.
What you still don't know (until you test it) is how your specific gun patterns specific shells. How well is a given shell going to cover a target at 15ft, 30ft, other distances, from your specific gun using that load? Just like accuracy with a pistol varies by ammo selection, so does a shotgun's pattern of shot delivered on target.
What pattern will you likely get? Won't know until you know, until you test it. It will your gun's barrel length, your choke type, the ammo, and how well your gun takes to that ammo choice. For example, my 870P is 14" smooth-bore with MOD choke. An Ithaca upland bird gun with 25" smooth-bore bbls and IMP chokes will pattern differently, with the exact same shell at the same distance.
The last question is that of penetration, of energy delivered on target. That's a fairly simple calculation. You can use the table of shot weight estimates from the article to estimate the energy delivered by your selected round. Let's assume, for simplicity's sake, that all pellets reach the target squarely.
Shot / Pellet Diam / Avg Pellet Wt.
#4, 0.24", 20.6gr
#3, 0.25", 23.4gr
#2, 0.27", 29.4gr
#1, 0.30", 40.0gr
#0, 0.32", 48.3gr
#00, 0.33", 53.8gr
#000, 0.36", 68.0gr
Using the formula E = 1/2 mv^2 (found on any number of web sites, such as this one: click), you'll get an estimate of the energy per pellet.
For example, The Winchester Super-X (XB121) 12ga 2-3/4" #1 Buck has 16 pellets of ~0.30" diameter and ~40.0grs each, moving at 1250fps from the muzzle. The energy delivered at 15ft will be somewhat less, of course, but the calculation works out to be: E = 1/2 mv^2 = 1/2 * (16 * 40.0grs) * (1250fps)^2 ... then adjusted for the units of measure conversion from Grains and FPS to the desired Ft-Lbs of energy. The calculator on the web site'll do all of that. For this shell choice, each of 16 pellets will deliver ~138 ft-lbs of energy, or ~2208 ft-lbs. The pattern at ~4yds was about 6-7" diameter, larger than a handspan. The coverage was more uniform and consistently broader than #00 at the same distance, for my tested loads.
Using another example, Winchester Super-X 12ga 3" #1 Buck has 24 pellets of ~0.30" diameter and ~40.0grs each moving at ~1040fps. The calculation results in, roughly: 96 ft-lbs per pellet * 24 pellets = 2304 ft-lbs. Little different than the #1, but coverage will be a bit greater in the spread delivered, at the expense of a bit more recoil. The pattern at ~4yds was about 5" diameter, roughly a small handspan. Two loads covered an area of ~10x12" fairly consistently, at that distance.
Personally, I'd prefer another 3-4" spread at 15-20ft, but that's just my own preference. I'm not going to be sending slugs 100yds at a target, but I'm entirely likely to be clearing a threat at the end of a hallway or across the room. Uncertain what pattern you'd prefer, depending on distance, load and purpose.
Simply compare numbers for your pet loads, and then you'll know. Apologies, but I don't have all the velocities and pellet counts for all of my favorite rounds, though I have some. Check the data on the boxes of shells you're shooting, head to the "energy calculation" web site.
The lighter shot you go, the riskier it gets in terms of penetration, as you know. My gauge is that anything under 0.30" per pellet is unacceptable. Your gauge might be that anything less than #00 size (0.33") is.
My basic criteria is that anything over 2000 ft-lbs delivered via pellets of at least 0.30" diameter that results in greater coverage area at the intended distances will end up more "devastating." You might have other criteria. YMMV, then.