Sorry, for the delayed response. I have been on a business trip.
This is not meant as a personal comment so please don't take it as such. As with many intelligent, inquisitive people you tend to overthink the problem. You are trying to interpret the results without having completed the experiment. First things first. You will answer some of your own questions and I will help with the rest.
The cant in the board is meant to introduce a destabilizing factor, as many hits on animals will. The worst result from yaw and tumbling in tissue is a deviation in path, but depending on many factors it can be quite beneficial to the overall lethality, if the path is straight. Determine that first.
Lets try to answer the "what ifs" as "whys".
Warren, thanks for getting back to me on this. I am still hoping for some more info before starting this test. I do not have any of the 173 HV bullets ordered yet so it will be quite some time before I can do it. I thought I would see if my gun shoots the 160 HV accurately before ordering the 173 HV and who knows when the 160s will arrive? As these bullets are hard to get and fairly expensive I do not wish to shoot more than necessary into wet paper. Should I just do it at 10 feet or at 400 yards or what? Again I wonder what you meant by saying "It will do, Okay"? Please clarify. Thanks again, Rufous.
What I meant is what I said. No codes, no secret handshake. If when trying to make it deviate from a straight line path, it doesn't, then that is in of itself a very good indicator that it did not destabilize in the media. This in turn is a good indicator of how it will perform in game. No path deviation = good performance in this case.
A recurring theme in your questions is the cost involved. To gain knowledge you have to spend time, effort, or money to acquire it. It is either that or believe someone who has spent the time, effort, and money when they share that information with you. If you cannot do either, then you should not start. I personally, am inherently dubious of second hand data. The more data, the more reliable the conclusions. Do not fall into the trap of drawing conclusions based upon a sample population of one or two.
If you want to know what it does at 10 feet, shoot it at 10 feet. If you want to know what it does at 400 yds., shoot it at 400 yds.
Warren, I am not trying to be difficult. I am trying to learn. That is why I and probably most people frequent sites such as this. Naturally I want to learn what I can from others' experience. I do not have unlimited time or money. If those who have done such experiments find that if the bullet will tumble at 10 feet then it will tumble at all ranges it would be futile for me to do it. Yes, then I would know first hand but I do not need that in all cases. It is ideal but not always necessary for me.
I have read many articles and posts by hundreds of people who say that Nosler Partitions are excellent bullets. I have used them myself and found the same thing. I have not read articles or posts saying that the GS Custom 173 HV 30 caliber bullet needs a 1:9 twist to prevent tublimg in game except by Gerard himself. I admit that he would be the first one to listen to, but based on other information I have on bullet lengths and required twists for them I do wonder if a 1:10 would suffice. I had hoped to hear from others who had shot game with a 300 Win Mag 1:10 twist using the 173 HV and either found good or poor performance. I would never have considered using Sierra Matchkings on game. It goes against all that I have read and learned over the years about necessary bullet construction to be used on big game. But there are so many who are using these "Match" bullets successfully that I may give them a try.
I was not looking for some secret handshake. I am just trying (still) to understand what you were trying to say. If we were face to face I have no doubt that I would understand what you were saying. The written word sometimes does not come across as easily understood. You said "It will do, Okay?" What I am still wondering is what is the "it" that you refer to and what is it that the it will do? Is it simply that if I do this test and find that the bullet does not tumble then I should be confident in using it for hunting? I appreciate your patience and your willingness to pass on to the rest of us your findings. Rufous.
I've kind of had this debate with myself already. Of course testing is always the best, but as you know GS bullets aren't cheap and they take quite some time to get....
I think the answer depends upon what you're hunting and what shots you're willing to take. I'm pretty sure I've heard Gerard say the 173's would be just fine in flight from a 300 Win with a 1:10. The problem is tumbling after impact.
If you're hunting deer or smaller game and limit yourself to broadside shots, then I would guess the bullet would do just fine whether it tumbles or not--dead dear!
But, if your style of hunting could have you following the trophy of a lifetime through the brush showing you nothing but his ass, if you want to take that shot you need deep, straight penetration--you can't have the bullet tumbling.
Personally, I'd take that shot. I want a bullet that will reliably penetrate from stem to stern--just in case. That's why I decided on the 160's. I don't have the time or money to test everything, so I figure Gerard wouldn't recommend what he does without good reason. That's all I have to go on. I know the high BC of the 173 is tempting, but when its maker recommends against its use from your rifle...is it worth the risk?
FWIW, I think one of the biggest reasons he is so strict about twist recommendations is how long his bullets are--after expansion. Most bullets will be reduced to about 1/2 their length or even less after initial expansion. His bullets only seem to expand back to about 3/4 of their length. So, their CG is much farther away from the force resisting the penetration. For the same angular deflection if they hit a bone or something there will be a larger moment trying to rotate the bullet...'n stuff.... [img]images/icons/confused.gif[/img]
Anyway, that's just my theory and I have no experience to back it up.
But, it's enough for me to just use the 160's until I rebarrel my rifle. That reminds me, if I want to test them by this summer, I had better order them now, eh?