Which group is best?

Group #4 is the best group….the reason is that there is no vertical or horizontal.
I would fine tune going .005" above and below with another round of 5 shot groups.
Then, with whichever is the tightest group, shoot a 10 round group and take note of the velocity and work out your ES/SD numbers.

Cheers.
Which is group 4?
 
Sorry, was looking at what QuietTexan was showing.
The .060" group, even it that fifth round is a flier.

Cheers.
The shot marked 5 was not necessarily the 5th shot. Not sure of the order, but I remember it as not the last.
 
Last edited:
All are as good as I can shoot. I can shoot a rifle pretty well. My shooter induced error is under 0.25 moa on a bad day and probably 0.1 moa on a good day , I would estimate.

That said, I didn't feel really great shooting that day…I was maybe 95%. My grip was messing with me. Basically, I took some careful dry fires and my crosshairs jumped 0.25 moa….I calmed down, looked through my fundamentals and got my dry fire jump near 0 moa….maybe 0.1 moa.

Still, I caught my grip in odd places at times after recoil.

I also try to wait a min between shots, but honestly my best consistency is one right after another. I was letting my natural cadence take over….maybe a shot in 25 sec.

The rifle should handle that. It has a #3 Brux, action bedded to a bedding block stock. It should handle some heat…
What was the weather like that day, temperature? I've seen mirage (heat waves) cause mysterious flyers. Either coming off the ground or off a warm barrel. No mention as to caliber or range. A magnum will heat up a barrel pretty quick.
 
All same powder charge. Three different distance to lands.

So, which one?
Did you use a chrono on these groups and are your SD's and ES's in good shape?
If so,
I would repeat group #1 then I would reduce seating depth to 0.035 to see if it tightens up any.
If results aren't satisfactory, then I would play around with group # 2.
I'm not crazy about how far off that flyer is but, if you take out the flyer that's the best group.
I might try it at 0.055 and 0.065
 
Last edited:
Load .037", .034", .031" off lands and test again.

.040" and .060" are basically doing the same thing but then .050" gets loose so inconsistent. Closer to the lands would appear to get better and suck those outlyers in. OR go the opposite and try like .090" off and start another test. Get away from the .050" on either side though.

Added: I re-read the labels, are you sure these are labeled correctly? With the .050" in the middle it is odd they did the similar with .040" and .060" and then .050" scatter. I would think it would be a little bit wider between the two.
 
Last edited:
What was the weather like that day, temperature? I've seen mirage (heat waves) cause mysterious flyers. Either coming off the ground or off a warm barrel. No mention as to caliber or range. A magnum will heat up a barrel pretty quick.
85 F; little mirage; no wind

100 yards; 300 Sherman
 
Maybe this helps….
 

Attachments

  • 0CA1451A-814D-4576-B090-9211AD936D81.jpeg
    0CA1451A-814D-4576-B090-9211AD936D81.jpeg
    1.4 MB · Views: 112
That 0.050" load just didn't repeat the 0.7" group….I don't know why.

It shot about 1.5" when I shot 5 groups of 5. The Sd got slightly worse too like 8 for 25 rounds, but I expected that.

So, now I have to choose. With work, I likely won't get in more load development before hunting season.

I agree, after hunting season, I need to wring out a better Sd by shooting more ocw groups at 0.040" and then step bullet seating from 0.010"-0.060" in 0.005" increments.

Unfortunately, that has to wait.
 
That 0.050" load just didn't repeat the 0.7" group….I don't know why.
Take a blank target and overlay all ten shots into a single group, and run the Ballistic-X calc on the total number of shots. You'll start seeing the true shape of the group by increasing the number of data points.
 
Warning! This thread is more than 4 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.
Top