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fliers
hadjii
Member Posts: 976 ✭✭
What causes fliers in group shooting? Seems like whenever I shoot a grouping, whether it be 3 or 4 or 5 shots, inevitably there is one shot that is perhaps 1 inch, and sometimes 2 inches outside the normally really good shot group. I weigh every charge, so the powder variance is not the problem. Is it just operator headspace out of adjustment, or could it be inconsistency in component manufacturing or just luck of the draw?
Comments
probably just the loose nut behind the trigger finger
[:D]
hadjii- Try this test (this is my own little thing that I do for myself).
Shoot 5- 5 shot strings and make note of which shot is the flyer in your group and make note to yourself. Was the wind blowing? Did I flinch? Was I in a good set posistion? etc.
Mine on average is shot #4 beacuse I get antsey for a good score/group
When shooting the .338 win mag off the bench I have to force myself to relax and roll with the recoil. If I don't it will toss one out of the group an inch or three.
too little or too much nk tension
anticipation
etc etc
how many rounds fired on the brass?
You brought up a couple of interesting points Justc. Seems like some of the bullets feel tighter than others when I seat the bullet. Brass is once fired. It also looks like the bullet is just barely seated, but that's the exact length given in the 2005 Sierra reloading manual. Also, should I be crimping these bullets in a 243? The OAL is 2.600" by the way, with Sierra 60 grain HP's. Powder charge is 43.0 grains of Varget, which is max load given in the same manual.
I would not be crimping rifle ammo if you are trying to obtain the most accurate ammo you can load. The OAL does not tell you much and I would not seat them to the books recommendations. Try seating your bullets somewhere around .005" off the lands...and that would be the length from the head of the case to the ogive on the bullet...not the OAL. BTW...I hate those darn flyers[;)]
OK, how about neck THICKNESS variances? do you have a NK micrometer? or access to a tubing mic? If so, check each case at "the 4 corners" (equal distance points around the neck, in 4 different places). Look for large swings in neck thickness. A variance of even .002" will cause large variances in NK tension. Also, if the brass is very thin, and the die body dimension is slightly large, then you could end up with almost NO nk tension because the die doesn't squeeze the nk down enough. Try checking the nk thickness variances, the sized nk dia and the seated round nk dia for starters.
Next, did you hold a bullet up next to a seated round to get an idea of how much bearing surface is being held by the case nk? If there is almost none, that can cause it. I have a 125gr NBT load for the 30-06 that to get to the lands in a ruger M77 is almost not even in the case. I hoped that pressing them against the lands would help with that, and it did, but only to a point. The load shoots well at 100yds, but goes to hell after that. If you are long seated with almost no bullet in the case, try pushing it back .020-.050" and see if it starts to improve. If this is a factory throat, you may have to settle for more bullet in the case and a longer jump to the lands.
let us know what you find.
Then reload the shell and shoot it again along with others. If that case again goes off center, you may want to check the neck thickness, trim it, or disguard the case. Another trick to watch for is the straightness of the bullet as it is seated in the case. What I do is "spin the case" 180 degrees when I seat the bullet by pulling the handle, spining it and lightly pulling the handle again. This almost always straightens them out. joe