I think all of the suggestions and thoughts are actually "right on" in a general sense. The "thing" that's 'getting to me' is that nothing really accounts for the very large size of the groups, and very few of these things are cumulative.

I considered the scope - more than once - however there are two observations that fairly well exclude the scope. 1) When I adjusted the scope at 50 yd, the adjustments were right on, and 2) the 3-shot group of the 125 Hornady was "good enough" or "better by a lot" than the ANVBs at 100. Both of those observations strongly suggest that the 'scope 'aint broke'.

Because I have only one cartridge in which I have ever had any luck with any ball powder - H-414 in the .17 Rem - I don't have any confidence in them. Since I don't have any confidence in them, they don't come to mind and when they do, my butt starts squirming in my chair as I consider using them.

I am quite certain that a large part of the variation in MVs is due to the magnum primer in a non-magnum case. Still, I simply can't get my head around the idea that the difference in MV due to primer type can account for a 2 to 3 inch increase in group size. I am also having a difficult time with the randomness of the groups. One 3-shot groups being strung VERY wide and the next being strung VERY vertically.

I have all of the above mentioned cartridges loaded. I'll shoot them and see what happens. I don't anticipate any serious improvement, but I am hoping for 2-ish at 100 yd with all of the factory bullets. I suspect that if they are 2-ish, that changing primers will bring them in to 1-ish. The only CCI primers I have are some large rifle benchrest. I would use those to start with, but I already have all of the cartridges loaded, and since I don't think the primers make 5 to 6" groups, I don't really want to completely disassemble these and reprime with the benchrest primers. I don't really want to use the "benchrest" primers anyway because I don't think the rifles I shoot and the cartridges I load are "fine" enough that a "benchrest" primer will make a measurable difference in group size.

The .338 Win Mag is going bear hunting.

News at 11.

Paul

Quote from: gitano;126000I am quite certain that a large part of the variation in MVs is due to the magnum primer in a non-magnum case. Still, I simply can't get my head around the idea that the difference in MV due to primer type can account for a 2 to 3 inch increase in group size. I am also having a difficult time with the randomness of the groups. One 3-shot groups being strung VERY wide and the next being strung VERY vertically.

Paul

I don't think that magnum primers are the cause of the nasty groups. I can't see them varying enough to make the shots string vertically in one group, then horizontally in the next. Does not compute.

I used to use magnum primers in my .223's when I was burning H335 by the bushel. The switch to "normal" primers and Benchmark had no real effect on the teeny groups, except to make them smaller yet.

RJ

Awrat, it is 11:00, where is the picture of either Yogi or Bobo hanging from the single tree?
Come on, come on, come on!

See the Campfire...

Paul

Playing with the boat is no excuse.

RJ

In this case, I think B.O.A.T stands for Bear Observation and Assault Transport!

Quote from: recoil junky;126030Playing with the boat is no excuse.

RJ

OK

There was neither "assault" nor "observation" of bears. There weren't any to be seen because even bears can't walk in 6 to 10 feet of snow. That is in large part precisely why they hibernate.

Paul

Just because the mission hasn't been successful yet, doesn't change the intended purpose of said vessel.  :grin:
I stand by my assessment.

When I first got the printed tips from j0e_bl0ggs, Jamie.270 mentioned that the REALLY pointed tip might be a problem. While I acknowledged the possibility, I wanted to give the "sharpies" a try first. As I clutch at straws to try to explain what I am observing with the ANVB, these SHARP points are getting more of my attention. The really sharp point always nagged in the back of my mind, but now, given the mystery of "not terrible" at 50 yd, and horrible at 100 yd, I am rethinking the issue and I can come up with a plausible - to me - physical reason why the "really pointy tips" could be causing the "spraying" I am seeing, as well as the nonlinear precision - ~1.7 MoA at 50 yd and 4 to 6 MoA at 100.

First, let me point out that the printed tips aren't PERFECTLY centered on the bullet. Now before you say "AHA!", let me make it clear that "out of alignment" NORMAL tips ARE NOT AN ISSUE for HUNTING precision. In other words, a "bent" or "mangled" tip DOES NOT change the the group size for rifles that shoot about MOA. However...

With my new process of fitting the points to the bullets after the bullet has been swaged, there is often a very slight bit of mis-alignment of the tip with the long axis of the bullet. With a "normal" plastic tip that has a relatively "round" nose in comparison with the "printed tip" - like on a Nosler Ballistic Tip - this would be no problem. However, with the extremely sharp point of the printed tip, (it can easily pierce the skin), I think this may be a real problem. Here's why:

Consider a bullet rotating freely after it has left the barrel. In a bullet with a "not sharp" nose, (hereafter "round"), AND slightly mis-aligned with the long axis of the bullet, the center of the rotation would still encompass the "roundness" (meplat) of the tip. Therefore, the tip couldn't "grab hold" of the air streaming by it. Conversely, with a tip that essentially goes to "zero" as the printed tip does, almost ANY mis-alignment would allow the tip to "grab some air" as the "tippy tip" rotates around the long axis of the bullet. (Jamie.270, could you locate the post you made with a link to I think the Berger website, about the rotational path of a bullet that is "out of round"? I looked, but couldn't find it.)

When I play this out in my mind's eye, I can see the circle of rotation of the whole bullet getting larger and larger as the effect gets more and more pronounced as the bullet's nose gets farther and farther out of alignment with the axis of travel.

As I said, I'm clutching at straws at the moment, but this explanation is getting a little more plausible as I consider it. It fits the observations without too much 'eye squinting' - namely "not too bad" at 50 yd - say less than 2 MOA - and horrible at 100 - 4 to 6 MOA. The "something" happening between 50 and 100 yd might be explained by the "sharp" tip "grabbing" the air due to minor mis-alignment with the axis of rotation.

The solutions are: 1) "perfect" the alignment, and 2) "blunt" the sharp tip. Perfecting the alignment is difficult - but not impossible - to accomplish, and the sharper the point the more difficult it is. Blunting the existing tip is easy. I will simply take a pair of fingernail clippers and clip the tip off to something like 2mm (~0.08"). Maybe 3mm (~0.120") If this explanation is in fact the cause of the bullet's strange behavior, the diameter of the meplat needs to be larger than the mis-alignment error. That would prevent the possibility of the rotating tip "grabbing air" and getting pushed to the side.

There are "factory" bullets 'out there' with fairly sharp points. Some military full metal jackets are pretty sharp. HOWEVER, those are "monobloc" bullets. In other words, the point is not a separate part of the bullet, and misalignment - if even measurable - is very slight. I'm also noticing sharper points on some plastic-tipped hunting bullets. I believe this is achievable due to more precise machining processes that make alignment much more precise.

I can achieve the necessary precision in my swaging process, but not without modifying the printed tip a bit. That's not a big deal, as these were definitely prototypes, and if blunting them resolves the problem, then we will have learned something valuable from them and can make the next ones "mo betta".

I should be able to test this theory in the next few days.

Paul

Quote (Jamie.270, could you locate the post you made with a  link to I think the Berger website, about the rotational path of a  bullet that is "out of round"? I looked, but couldn't find it.)

The post is in the "Boolit Going to Sleep?" thread, here:
http://www.thehunterslife.com/forums/showthread.php?t=15072&highlight=litz&page=2

The video is still up, and is located here:
http://www.youtube.com/watch?v=KH9SCbCBHaY
[/SIZE]

Here's a VERY interesting video where the shooter purposely unbalances a variety of .22 bullets by taking a file to them.
He both unbalances them, AND grossly alters the shape of the nose/ogive.
Interestingly, at the 2:50 mark in the video, he shoots one that is obviously unbalanced, but with the nose of the bullet left intact.
It shoots straight.

http://www.youtube.com/watch?feature=fvwp&NR=1&v=C9Dylxy3zJc

You may be on to something Paul.

Thanks, Jamie.270.

Yeah, I saw the .22 RF video. Pretty drastic modifications with respect to the percentage of the bullet's mass that was removed in the mod. I would have liked to have seen two "things":

1) A target with out the mods, and
2) A target with the mods.

I would like to have seen the percentage of weight that was removed. I may have to repeat this "experiment with a little more scientific rigor.

So I did the modification - clipped the tips - of the ANVB with the printed tip. I knocked off enough to create a 2mm meplat. Here's what they look like now.



If you look closely, you can see the tiny bit of mis-alignment at the edge of the mouth of the one on the right. That mis-alignment is actually less than the meplat of the "sharp" point, and that's why I didn't think it was an issue. And it may not be. I won't know until I shoot these.

I also made up some lead-tipped 125s. With this point forming die, I cannot make a meplat smaller than about 0.100" or 2.5 mm. Also, since they are the same weight as the printed tip 125s, the bearing surface is significantly smaller - about 0.250" for the lead-tipped versus the 0.354" of the printed tip. THAT means that I will not be able to get closer than about 0.068" off the lands if I seat the lead-tipped bullet to the minimum of 2/3rds of a caliber - 0.216". Here is a picture of the first three I made. The one in the middle is the last one after I figured out the depth setting on the die. It's meplat is 0.100".


I've got 9 of the 'clipped tip' bullets loaded up, and will shoot them with the rest of the ones I loaded up for the next test. So I'll be shooting 180-grain Nosler E-Tips, 195-grain Hornady Interntionals, 125-grain Hornday Spitzers, the Turkish Military 150-grain FMJ Spitzers, the 130-grain ANVBs with clipped printed tips, and the 125-grain ANVBs with the clipped tips.

We are currently under a "Winter Storm Warning". Four to six inches of snow, turning to freezing rain. Probably won't be shooting these any time in the next two days.

Paul

:nana:Gonna let some typical spring weather slow you down?

With this snow a record was set for the longest snow season - 231 days since the first measurable snow.

It started snowing early this morning, and is still snowing now. Getting old.

Paul

See here for some late night musings on the issue of points: http://thehunterslife.com/forums/showthread.php?p=126076#post126076

Paul