I meant to post my thoughts on the test right after, but have too much on the go and it's hard to keep up with everything. Anyway, one of the things I was surprised with was that on the angled test, the .270 bullets both penetrated quite deeply, even though one was soft nosed and one was plastic tipped, which are supposed to make them expand rapidly. I thought they would deflect or lose all their energy almost immediately by over expanding. So does this cast doubt on the theory that a bullet can glance off a bears head? I suppose would have to test some shallower angles to get a more conclusive answer. I think the key difference between the light, fast bullets and the heavy, slow slugs is that while the bullets may have penetrated further, they also veered quite far from the path of travel, and lost much of their weight. So in a bear they may not reliably continue straight into the area being aimed at, and if they do, may not have enough mass left to do sufficient damage.
The brass slugs seemed to leave a more distinct wound channel, I think because of the flat front and sharp non deforming shoulder. They end up tearing or cutting a hole equal to their diameter, whereas the lead slugs look like they squeezed between the wood fibers, which expanded slightly back into the wound channel after. However, I'm not sure how this relates to performance in soft tissue, it might not be as relevant.
There was greater deformation in the angled shots. I found this interesting because projectiles that are designed for a balanced amount of expansion in perpendicular ballistics gelatin may over expand/deform in a real world situation where it is passing through one or more bones at different angles. If designing for a worst case scenario, this may mean the slug should be quite a bit harder than one might first think. I wish I had been able to test the Federal foster slug on the angled target, as the results would have been useful, but I was out of shells by that point. Given it had expanded about as much as it could without disintegrating on the perpendicular impact, I suspect it would have broken up into a few pieces and not penetrated as deep as the brass slugs.
Finally, I was expecting deeper penetration overall from the slugs, but I guess it's relative, since the target was very hard and dense compared to something like ballistics gel. I used what I had on hand, to make consistent replaceable targets, but next time I'll have to use something a bit more representative of the real thing. Perhaps some sort of soft medium separated every so many inches by a hard layer.
Hadn't heard of filling the base like that before, I'll keep it in mind. Those slugs look like a foster but with a cross piece cast inside to support the sides? What did the expanded slug look like after penetrating that far?
How much would one of these typically weigh? Presumably you could get the same result by loading a sub-caliber slug in the shotgun shell. The sabot slug I tried was .50 caliber I believe, but soft and tipped, not hard cast. But I think this would make a smaller wound channel and do less damage if I can achieve sufficient penetration with a full caliber slug.
This article http://www.fs.fed.us/pnw/pubs/gtr152 on short range terminal ballistics by the US Forest Service lists a 12 gauge foster slug and a round nose soft point 45-70 as penetrating roughly the same amount with roughly the same weight retention, but the 12 gauge ends up with a final expanded frontal area of .71 square inches, compared to .33 for the 45-70. A hardcast 45-70 would penetrate further, but then so would a hardcast 12 gauge. It seems like the extra mass of the larger slug makes up for its increased frontal area, at the same velocity.
The brass slugs seemed to leave a more distinct wound channel, I think because of the flat front and sharp non deforming shoulder. They end up tearing or cutting a hole equal to their diameter, whereas the lead slugs look like they squeezed between the wood fibers, which expanded slightly back into the wound channel after. However, I'm not sure how this relates to performance in soft tissue, it might not be as relevant.
There was greater deformation in the angled shots. I found this interesting because projectiles that are designed for a balanced amount of expansion in perpendicular ballistics gelatin may over expand/deform in a real world situation where it is passing through one or more bones at different angles. If designing for a worst case scenario, this may mean the slug should be quite a bit harder than one might first think. I wish I had been able to test the Federal foster slug on the angled target, as the results would have been useful, but I was out of shells by that point. Given it had expanded about as much as it could without disintegrating on the perpendicular impact, I suspect it would have broken up into a few pieces and not penetrated as deep as the brass slugs.
Finally, I was expecting deeper penetration overall from the slugs, but I guess it's relative, since the target was very hard and dense compared to something like ballistics gel. I used what I had on hand, to make consistent replaceable targets, but next time I'll have to use something a bit more representative of the real thing. Perhaps some sort of soft medium separated every so many inches by a hard layer.
Hadn't heard of filling the base like that before, I'll keep it in mind. Those slugs look like a foster but with a cross piece cast inside to support the sides? What did the expanded slug look like after penetrating that far?
How much would one of these typically weigh? Presumably you could get the same result by loading a sub-caliber slug in the shotgun shell. The sabot slug I tried was .50 caliber I believe, but soft and tipped, not hard cast. But I think this would make a smaller wound channel and do less damage if I can achieve sufficient penetration with a full caliber slug.
This article http://www.fs.fed.us/pnw/pubs/gtr152 on short range terminal ballistics by the US Forest Service lists a 12 gauge foster slug and a round nose soft point 45-70 as penetrating roughly the same amount with roughly the same weight retention, but the 12 gauge ends up with a final expanded frontal area of .71 square inches, compared to .33 for the 45-70. A hardcast 45-70 would penetrate further, but then so would a hardcast 12 gauge. It seems like the extra mass of the larger slug makes up for its increased frontal area, at the same velocity.
