Originally Posted By: 204 ARWhat, if any, difference have you guys noticed with faster vs slower twist rates relating to bullet expansion?
Me personally, I haven't shot enough coyotes with any given bullet to really judge it. I can say I've shot exactly ZERO with a 22 vmax. I've been using 6mm 87 gr vmax at 3k fps for a couple years, and so far nothing moves far when hit with that one.
I think you are asking and making a very good observation. I don't think that there is any ONE magic bullet. Different bullets coupled with different velocities and twist rates all seem to change the results. For some guys, dead is dead, end of story. For me, even when they dropped, I would open them up and take a look at internal damage, bullet expansion, depth of penetration, so that I could make better, more informed decisions.
Originally Posted By: obaroJust shooting prairie dogs I can tell a significant difference in what 'I think' is performance due to twist rate. The tighter twists seem to cause the bullets to come apart more violently. I have had the chance to shoot the same load from guns with different twists. I didn't run the loads through the chrony, but the longer barrel had the slower twist, so in theory should have had a velocity advantage. The shorter, faster twist barrel seemed to cause more terminal damage. More 'lift' on impact, and more pieces thrown further from the carcass. Nothing scientific at all, just my observations in the field. Seems like the slower twist was a 12 and the faster an 8, could have been a 9. Both those barrels shot very well, but have been used up in the dog towns.
It does lead me to question if the more violent expansion leads to less to penetration, though.
I think that Obaro and Steve make some great points. I have wondered about the thin jacket causing inconsistent expansion. On some, it seems to explode spectacularly on impact while on others it seemed to zip right through. I wonder if some of the tips blow open like they are supposed to while others deform inward and become FMJ's for all intents and purposes. Might explain some of the inconsistencies we see.
For me and my partners we spent a lot of time trying to find a combination that would work dropping coyotes in their tracks. But int he winter, we hunt fur, foxes and bobcats, which have much thinner pelts where pelt damage was an issue. What we figured out, at least in our results, was that there was fine line between depth of penetration, speed of expansion, bullet design and velocity. For example, we tested the .17 Remington. With a BT bullet, we got a LOT of pelt damage. Yes, it killed them, but it was ugly. But slower BT's resulted in runners. When we went to HP's, we were getting one hole wonders with spectacular terminal results and no fur damage. It seems that you need to get the bullet into the muscle BEFORE it expands. But once it starts expanding you need that to be rather explosive. Slow expansion resulted in runners.
Some calibers seem to change the expansion characteristics in some bullets. My hunch is that weight and velocity along with the diameter of the bullet play the biggest part in that recipe.
Originally Posted By: liliysdadYou have made it obvious that you are averse to modern trends, such as fast twists, high BC bullets, and polymer tips. I can only speak from experience, but I have had much, much better luck with all of the above, and see no reason to revert to old tech.
Not at all. I have run 17 Remingtons, .204 Rugers, .223 Rem, 6.5 Grendel, .308 win and 12 gauges for all kinds of different varmints. I have used Tungsten loads, Vmax, SST, HP's, SP's, Steel shot, lead shot, copper plated lead shot, in a variety of platforms from single shot breech loaders, pumps, bolts, levers and semi-auto platforms. I have run suppressed and un-suppressed. I have to. I build firearms for a lot of different people and I need to know what works and what doesn't. Just because a bullet worked at one time, doesn't mean that it will work forever. Hornady itself realized that they were having issues with the Vmax poly tip so they changed that formula because they found the tip was melting in flight. Don't think that will effect a bullet's flight and terminal characteristics? I do, so does Hornady.
I am fine with trying out new things, but I am also willing to admit when something does or does not work and I don't mind sharing when it does or does not work. That's how our industry progresses.
I am not trying to tell anyone that they need to change away from something that works for them. I am just sharing my results.