LlindeX wrote:Hoot,
Thanks for getting back on this. I believe you that it's not the bullets beginning to open up, but I must be a bit dense or something. How is it that the looseness of the target against the backing is causing the extreme scalloping pattern around the edges? As you say, it definitely is variable from sheet to sheet because the A1680 sheet really shows it the most. The holes in that sheet really look like little flowers.
Are the actual holes through the paper smaller than .45" and they have a black ring around the outside of them that shows the rifling grooves in the bullets? Are the jackets of those 45 cal. Barnes bullets visibly cut to enhance opening? Could that be what causes the scalloping effect? I understand that in the situation you describe, the bullets wouldn't cut a clean hole in loose damp paper, but what is the cause of the consistent and even flower shaped pattern of tear? All the "petals" of the shapes seem to be evenly shaped. I have never noticed this occuring before, but then again, I don't shoot much damp paper out here in the low humidity we have.
Without high speed footage, I can only speculate upon what IMHO, I think is happening based upon my knowledge of material behavior gathered over the years.
There are many factors at play here. The Luan, after having been rained on and sun baked dry tends to get more brittle. As the large frontal area of the bullet strikes the paper, it first pushes it into the Luan and depending upon how fresh it is, it sometimes punches out a clean hole shearing the paper around the perimeter as the bullet passes through like a paper punch works. Some times, the Luan splays and splinters before giving way and the holes are more jagged. In the case of several nearby holes, it may break away an area of wood greater than the diameter of the individual bullets and the paper tears in unpredictable ways inconsistent with the bullet shapes. The paper doesn't go from dry to moist to the touch from the humidity. It just swells a little and gets more supple and leathery. I suspect that how cleanly the holes get cut is most likely dependent upon how fast the bullet is traveling. Experience seems to show that the faster the bullet is traveling upon impact, the cleaner the holes are cut and there is a correlation to the bullet diameter as well. The smaller the bullet, the less velocity is needed for a clean cut. These
tootsie rolls we're shooting need a lot more velocity than 1900 to 2200 to get a super clean hole. I have not shot any "wad cutter" bullets from the 450b yet, but there seems to be little difference in the predictability of the hole shape between pointed bullets, gaping hollow points and truncated cone hollow points like the XPBs. What may appear to be a conclusive result one range trip turns around and is different the next one. I do know from experience at out local range, where the sun arcs behind the shooter from right to left, that on a hot, dry afternoon shooting session, the holes seem to cut more cleanly. Again, there are many factors the support and contradict behavior from one day or time of day to the next. I have never payed them much heed.
I remember someone donated some 1/2 inch particle board sheets once and we thought they would exceed the performance of the Luan. Quite the contrary, the bullets blew large quarter sized holes out when they hit and the definition of the bullet holes were completely lost. after several shots close to one another, there was a resulting conglomerated hole you could throw a golf ball through. I've been maintaining the Rifle Range for about 7 years now and Luan is by far the best bang for the buck. Some of the serious paper punchers in the club bring large sheets of cardboard and staple them to the boards, then their targets to them and some times they leave the cardboard behind when they're done. I've use them a couple of times and they give beautifully defined bullet holes. At least until the first time they get rained upon. I'm too lazy to save sheets to bring with me, despite having access to all I want from work where we normally put them out for the recyclers to pick up every Thursday. I can't believe I've typed so much on this subject the past few posts. In synopsis. I've shot a lot of different bullets from my 450b and have yet to suffer a single keyholer or ones I can say for certain, were arriving at the target skewed in any way. I've had a few that disappeared over the years, never to be found and not a clue as to why. When the target boards get shot up pretty bad, but not bad enough to replace them, it gets hard to spot shots off the paper, but that you know hit the board from the resulting thwack heard afterward. Now there's a good reason for bringing a roll of butcher paper as backing, which I've seen some members do when they're sighting in a new scope. I just never think of that until I'm there. As the person who controls the replacing of the boards, if I'm the first person to the range in the morning, I've been know to throw away the worst target board of the 14 of them there, put the shot up one at my favorite position (#3) in it's place and put up a flat, fresh one for me to use. That's a small perk for doing the work. It's kind of awkward to do that when there are members already there as it's pretty obvious that I'm being selfish. I prefer to be selfish in private.
Hoot's Serenity Prayer: God grant me the ability to walk away from a conversation. The wisdom to know that's what I need to do and the ability to do so with aplomb.
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