THE CAST BULLET 5 SHOT 100 YARD HALF INCH AGGREGATE HURDLE IS ALIVE AND WELL

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joeb33050 posted this 10 January 2019

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John Alexander posted this 10 January 2019

Joe,

I have just checked the results for the last two years and see that your numbers are for 5 shot groups at 100 yards -- the easiest measure.

For those who consider ten shots as the proper number of shots the hurdle is at about .75 for four ten shot groups at 100 yards.

Putting your graph into words. On average less than two shooters per year manage to shoot four 5-shot groups at 100 yards smaller than .5 inches.

And the figures above are for custom built guns usually costing several thousand dollars and a field full of wind flags.

For factory or military rifles (CBA Production, Hunting Rifle, or military) the barrier seems to be about 1.0 inches for four five shot groups at 100. There are a few aggs below 1.0 inches but an inch agg will usually get you the win.

Some may point out that our records are much lower than the figures above. But a record doesn't represent reality but a rare event.  No CB shooter can do on a pre-selected day. That argument is in the category of a thousand monkeys with a thousand typewriters writing a Shakespere play in ten years.

Thanks for taking the time to compile your graphs and remind us of reality.  It's sometimes hard to remember with all the claims being made.

John

 

 

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frnkeore posted this 10 January 2019

I don't understand why this isn't done in MOA, at least for CBA.

After the groups are tallied (both 100 & 200 yd), they are converted into MOA and so they can be directly compared.

For overall accuracy, why not do this in MOA?

Frank

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Paul Pollard posted this 10 January 2019

John Alexander said, "And the figures above are for custom built guns usually costing several thousand dollars and a field full of wind flags."

Dolly Parton said, “It costs a lot of money to look this cheap”.

To paraphrase her: It costs a lot of money to shoot this bad!

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RicinYakima posted this 10 January 2019

Frank, we do for 5 shot groups aggregates in matches.  You can look up the match results and see them.  Ric

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M3 Mitch posted this 10 January 2019

Well, even with jacketed bullets, even with match bullets - if you can shoot a 5-shot half inch (or half MOA if you prefer, they are close enough I would cheerfully give full credit for either) more or less on demand, if only on a relatively windless, clear day - that's damn good shooting in my book.  Regardless of scope magnification - use all the power that mirage will let you get away with - it's damn good shooting. 

With cast bullets, which at the very least are more prone to wind drift - it's phenomenal!

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frnkeore posted this 10 January 2019

Yes, I know that CBA does that and that is what I was suggesting that JoeB do, is his calculations in that format.

I think that the individual clubs should also be added to the data. There is more to the CBA than just the "Nationals".

Frank

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John Alexander posted this 11 January 2019

Since the information presented in this thread is all for 100 yards it doesn't really make much difference and inches are slightly more accurate since MOA and inches at 100 yards are not exactly the same and we measure in inches.

I agree that including the individual clubs would be nice but would it change anything?  Too bad we have only one joeb to do all the work.

John

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frnkeore posted this 11 January 2019

I agree that including the individual clubs would be nice but would it change anything?  Too bad we have only one joeb to do all the work.

John

Nice?

It could make a lot of difference, couldn't it? We will never know if it isn't included.

Joe took it on himself to what he has done and I always hear him saying that he needs "more data" from others to prove what they suggest. The data is available and there are other <.5's shot at the other clubs, through out the USA. Roseburg is one of them.

Frank

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joeb33050 posted this 11 January 2019

I went through the six 2018 TFS match reports. Of 125 5/100 aggs, 4 were < .5". This is about what the National data shows.

The CBA nat group results come in: shots/group (5&10,, range (100 & 200) and class (PPB, PRO, HVY, UNR, HNT, UNP, and, seldom, LRH) 6 or 7. So, there are 2 X 2 X 6 or 7 = 24 or 28 categories.

The club match results add 9 (in 2018 TFS) clubs, expanding categories >200; and there's no way I know to present data sorted 4 ways. 

However, 5-shot 100 yard aggs < .5" are rare, ~1/30. A hurdle.

(Excel workbook available on request.)

 

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John Alexander posted this 11 January 2019

Jim wrote:

"Are we arguing that we aren't producing smaller groups year over year? Are we arguing that the Nationals results are a reasonable proxy for CBA trends on the whole (or not)? Are we simply trying to define where the prevailing accuracy boundries are for the various classes of rifle? What?"

=========

Jim,

It seems to me that Joe has already answered your first two questions.  I also think he has defined the present accuracy hurdle for custom built rifles and URP.  I have taken an informal stab (above) at the present hurdle for factory rifles by spending an hour or so noting that  1 moa will usually win at 100 yard five shot group agg.  For 10 shot groups, or at 200 yards with either 5 or 10 shot groups a significantly larger aggregate will win almost always.

I think the answer many of us would like to have is what will it take to lower these hurdles.  I think the answer is trying new things and running valid experiments to find if they help and --  and I don't mean trying to find out if 22.1 grains will shoot better than 22.3 grains.

If CB shooters are doing much of the kind of experimenting that will break barriers they must be keeping it to themselves.

John

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tlkeizer posted this 11 January 2019

Greetings,

For minute of angle (MOA) at 100 yards from inches, just multiply inches measured by 1.047.  My eyesight isn't good enough any more to see .047 inches.  However, if I am really close to an inch but not quite there, I could multiply my group size in inches by 1.047  to see if I got under 1 MOA.    This is not to be a "PA", just thought someone might like to know the conversion factor.  Internationally I am sure MOA is much better received than inches, but I still like American Standard rather than metric for nuts and bolts too.

Waiting for temps without the minus sign so I can get back out to the range relatively more comfortable.

TK

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