Reduced recoil loads are really reduced power/energy - whether that's good or bad....
This is a follow up on a thread I started about reduced recoil 00 pellets having the same energy as many .380 loads and I wanted to just add some awareness about reduced recoil loads. I'm in no way saying they shouldn't be used - that's entirely up to you. All I want to accomplish here is to make sure we are accurately aware of what low recoil loads actually are.
I think before going on, I'd like to address a trend I see all over the internet. The vast majority of posters that refer to the effectiveness of a particular load only concern themselves with the pattern the load produces. That's all - the effectiveness of the round as a man stopper is based on pattern alone.
The assumption is that if the pattern is good, the energy will be there. However, there is some reason to question the validity of that assumption. Low or reduced power rounds, advantageously marketed as low recoil, may not hold up energy-wise at 25 yards that most pattern-only based evaluators set for 00 buck. Sure, the pattern can look really good, but does it deliver the energy/momentum required for adequate penetration you are assuming it will?
Actually, none of the following matters if street results show reduced power loads effective at the ranges we are considering. However, reports from the street do raise doubt. We have seen two reports of failures of Federal 132 00 reduced power loads from the street in real-world shootings.
One report was posted in my other thread by a police officer that has seen numerous failures on large dogs and people.
Another report revealed that at 40 yards, and I agree that's stretching the range a bit, but that same load wouldn't even penetrate a 'cheap leather jacket'. Again, 40 yards does push the range, but that was those officers' reality. They were loaded with low power and it didn't do the job. If they had had full power loads we might have seen an entirely different result. Plus, many a deer has been taken with full power 00 at about the 40 yard range and apparently the full power penetrated the deer's leather jacket.
Again, it is not my intent to condemn low power loads, but to explain exactly what they are, how they work, and why the effective range may need to be adjusted back from the generally accepted range of 25 yards to 19 yards.
Low recoil is actually low power loads - nothing more. So why are they called low recoil? Who would want to shoot a reduced power load if they could shoot a reduced recoil load? Unfortunately, there are no shortcuts or magic to reducing recoil produced by rounds. There are only three ways to reduce recoil via the round itself, reduce the mass, reduce the velocity, or both. Here's a comparison to clarify that:
A 12 ga full power load launches 9 00 pellets from the muzzle at 1325 fps. That produces an energy of 1890 ft-lbs. A popular reduced power load is Federal LE or PD 132 00 which also consists of 9 00 pellets, but they reduce the muzzle velocity to 1145 fps which yields a muzzle energy of 1415 ft-lbs. That's a difference of 479 ft-lbs. How much of a difference is that?
Well, 1890 ft-lbs is 34% more muzzle energy than 1415 ft-lbs. IOW, the muzzle energy of a reduced power load is 75% of the full power load. In fractions, a reduced power load has 3/4 the energy, at the muzzle, of a full power load. But, there's nothing wrong with shooting a load that's 3/4 of a full power load as long as we keep it within its effective range.
There are three characteristics to be aware of: Energy delivered, pattern, and penetration. When I discussed this in the other thread, I lost some folks and it took a long time to get everything clarified and I want to avoid that this time, so I'm gonna use two examples to illustrate the principles involved.
I'm going to take patterning as a given and assume the pattern is fine. We have to understand why individual pellet energy is significant and that in one case the pellets' energy that strikes a target adds and in another case they act totally as stand alone projectiles. This is where I lost some people in the other thread; they could not see the significance or relevance individual pellet energy. Let's start with the additive effect of pellets on a target.
Let's say we set a steel plate to fall with a 9mm, 115 gn, 1150 fps bullet striking the upper half of the plate. So we tune our adjustment screw and shoot iteratively until it's adjusted properly. Now what would happen if we shot the plate with a bullet that weighted 54 gns, less than half of the 115 gn 9mm, with a velocity of 1145 fps - would it knock the plate over? No, it's not up to a 9mm 115 gn bullet ballistics the plate is adjusted to. But a single 00 pellet is exactly 54 gns at approximately the same velocity. Now to illustrate the additive effect.
Next we consider two 54 gn pellets hitting the plate, will that knock the plate over? Yes, because the combined weight, velocity, and hence energy of two pellets nearly matches the ballistics of one 9mm the plate is tuned to.
So what do we deduce from this? Well, it takes two low power 00 pellets to equal the energy and momentum of a single 115 gn 9mm bullet. That's for impact or shock, but what about penetration? Let's look at that next.
Energy and mass of the bullet is what drives it into the medium, regardless of what the medium is. In the case of the steel plate, penetration was not an issue at all. That example really illustrates the conservation of momentum and that the energy and momentum of the pellets are additive in that case. Now we will replace the plate with ballistic gel. In this case we will be looking at penetration and the stand alone implications of the energy of the individual pellet.
Let's start slow. Will a 54 gn, 00 pellet penetrate as deeply as one 115 gn, 9mm round with the same velocity? No, it won't, theoretically, since it has half the mass, it has half the momentum and energy, it should penetrate about half as far as the 9mm.
Let's say we hit the gel with two 00 pellets and they are separated by 2 inches. That's just an arbitrary distance, it's only used to help with the visualization. It simply eliminates any stacking effect. That's justified because at 25 yards there is little chance of stacking. The question is will these two pellets penetrate deeper than the single pellet in the previous example? No, they won't, why? Because the only thing driving the pellet is the energy and momentum of the pellet itself - it gets no help from the other pellet.
Now we jump - what if 9 pellets hit the gel and there is no stacking? Do all of them some how magically penetrate deeper? No, there's no way any of the pellets can help each other. There can be some path intersections, but is that something we want to bet our lives on?
However, what is the total energy delivered to the target? It is the sum of the individual pellet energies. So we have additive impact, but stand alone penetration effects.
What this all boils down to is we can have a lot of energy delivered due to the additive effect. But even with all that energy delivered, we can still have poor penetration due to the stand alone effect of individual pellets.
I guess the bottom line is, understand what reduced recoil really is. Reduced recoil is not produced, low power is produced and it results in reduced recoil. Reduced recoil is a side effect of reduced power, not the other way around.
And, think about this. If full power 00 is effective to 25 yards, what should a load that is 3/4 of a full power load be effective to? How about 3/4 of the range? Or, 19 yards.
Just be careful you're not expecting full power load performance from reduced power loads. If it's enough for your purposes, then fine. But if you're pushing it to full power expectations it would be prudent to consider a full power load instead of the low power.
Or if you are expecting effective barrier penetration, keep in mind that full power isn't all that great of a barrier penetrator to start with, depending on what the barrier actually is. It was a cheap leather jacket in one instance.
To illustrate the relevance of such considerations, I'll leave you with this problem: If you have a choice of two loads, and they both have the same muzzle velocity and one load is 8 00 pellets and one is 9 00 pellets, which would produce the most recoil and by how much, and which would have more penetration capability?