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GeorgeC
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Re: NOE 321187
Reply #15 - May 20th, 2016 at 9:43am
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J Louis,
Do you use the Greenhill Formula for figuring twist?
There seems to be differences of opinion on the Greenhill formula. 
I used several versions of Greenhill formula and came up with twists of 16, 14, 12 (all rounded off). 
So, what if someone chooses 1:16 twist and then decides to use a heavier and slightly longer bullet that would require a faster twist, say 1:14 twist. Do you think that the accuracy will fall off using a longer and heavier bullet in the original rifle with a 1:16 twist?  Would not our shooter be better off using a 1:15 twist? 
I thought this was an interesting formula for figuring bullet length.
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JLouis
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Re: NOE 321187
Reply #16 - May 20th, 2016 at 12:17pm
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George the Don Miller Twist Rate program seems to be the best I have found. You should be able to find it very easily by doing an Internet search. Bullets and rifles are interesting individuals, I have had bullets that should not shoot in a 16 twist shoot very well and bullets that should shoot very well that won't. I have been extremely fortunate in that I have always had access to a variety of designs and weights to try and to pick from so I have never had the need to rely on a twist rate formula. I also feel there is a fine line in regards to over spinning a bullet and or under spinning a bullet to achieve the best in accuracy and a tendency for us all to do both and then we miss out on that special sweet spot where a bullet reaches its maximum point of efficiency regardless of its design in ones particular rifle and twist rate. Having shot through the Ohler 43 Ballistcs system and reviewing several pages of data while using a wide variety of bullets one can actualy see this taking place so it is a tad more than just my personal opinion. Unfortunatly this does mean that every bullet that reaches thier maximum point of efficiency will turn out to be the best choice in achieving ultimate accuracy but there will generaly be one out of that various group of bullets tried that will. In my case in regards to my 32-40 with a 15 twist it turned out to be the Darr 370B, a cylindrical FN bullet .960 long and weighing approx. 190grs. The ease of consistently shooting extremely small groups was almost unbelievable and the wind effects were quite a bit less than the spitzers as provided by the ballistcs system. I beleave this was attributed to the yaw, pitch and nose attitude being close to perfect and thus providing per-say a perfect and repeatable flight to the target shot after shot after shot. I used this same bullet to break the ASSRA 5-5Shot 100yd. Group Average back in 2013 a personal goal for that year and I was able to do so with a 0.3882 average. Prior to going for the record I shot 13 consecutive 5-5Shot Group Averages of .500 and under with the smallest being 0.198 and several in 0.200 and 0.300 range. I bring this up only to point out what I would consider to be a perfect match of bullet, twist rate, velocity and the highest degree of in flight efficiency. Bottom line is I do not beleave that any of the twist rate formulas can get one to this point but only to a starting place for one to begin his exstensive testing to achieve the same results. 

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calledflyer
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Re: NOE 321187
Reply #17 - May 20th, 2016 at 1:52pm
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Like John, I think rifles are individuals. My particular rifle in the subject caliber has the 16-twist barrel, but it seems to greatly favor bullets on the blinkin' edge of the formula's length recommendations.
And, like him, the favored bullet is a fat nosed one of 196 grs. Similar traits to his choice. Mine was a lucky find from an ebay sale of Jerry Simmons items. 
That said, I sort of wanted one of the molds from Frank's group purchase, but passed because of the pointed shape/length combination. 
So, I'm very anxious for some of the buyers who use the slow twist (16:1) to report back with results. So get with it guys, I need to hear from ya. Cool
  
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JLouis
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Re: NOE 321187
Reply #18 - May 20th, 2016 at 3:36pm
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Like you CF I am also interested it is a nice looking bullet and I have had several similar to it longer, shorter, sharper nose design, more lube grooves etc. What I find will be interesting is the variety of twists, groove and bore diameters, lead angles etc. it might be shot in and if two or more indivduals end up having like results? As you stated each one is trully an individual and often times than not what works best in one will not work quite as well in another even if they are per-say exactly the same in all deminsions and cut with the same reamer. That is what makes these single shots so interesting as the search for perfection in accuracy is endless and there is always a tad more to had if one has the drive and can take the time to find it and they trully do provide a lifetimes worth of seemingly endless variations to try along the way unlike the most of the current more modern designs now being produced. After sixteen years I seldom leave the range without something coming to mind that I have yet to try and then will. The rifles might be a bit pricey but one is guarenteed to get more for the money than one could have ever dreamed possible based on my personal experiance. My poor ole CPA 32-40 now has over 144,000 bullets down the bore in my quest to seek the perfect combination and all though the barrel is a little tired and has lost some of its edge it will still hold its own competively. The time has now come to try and do the same with my 28-35SS as I have always felt that the 28 was a sleeper and a great choice for competitive use so it too will be an interesting adventure and possibly my last as all of the variations yet to try will surely out last the competitive years I still have left and extensive experimentation as was done in the past with the 32-40 has become more challenging due to health reasons and my now fixed income but the Joy in doing what I can along the way will always be there
and it is trully priceless.

If anyone here is contemplating buying a single shot and entering into Schuetzen competition I hope this helps to sway your decsison as it will trully become the best money you have ever spent and the friends you will aquire along the way priceless. This also holds true for those who simply enjoy shooting them for just the joy of it who also visit this site.

JLouis
  

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JLouis
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Re: NOE 321187
Reply #19 - May 20th, 2016 at 4:30pm
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George C while on the subject of twists I thought you might find this bullet design of some intrest. It is the one I am currently using in my 28-35SS in my quest to find the perfect bullet match for this rifle. The bullet is a bore riding truncated nose baseband design, the entire nose section in front of the baseband is bore riding, length is 1.070. weight 154.3grs with 1-20 alloy. Barrel is a Douglas XX 12 twist and I don't know what the twist rate formulas might have to say as I have never bothered to check? This bullet was made for me by dear friend Barry Darr and as you can see it is not of a more typical design. Load is 12.8grs. 300MP and Fed.210 primers. I have yet to chronograph it so the Vel. is still an unkown. This bullet flies point on and with this load I have not seen any signs of tipping to date and as you can see by the targets it has also been shooting very well and I have several more with similar results but allot more testing yet to do while looking for the day in and day consistency needed to remain competitive. I have yet to find extremly good shooting conditions so far but it has been holding its own in the real rough ones if I do my part in reading them correctly. Unlike most spitzers I have shot over the years the nose design does not seem to be as ill affected by stronger than normal wind conditions so far and I have high hopes for it but only time and a multitude of pratice targets will tell me what I need to know as being more factual and exactly what I am looking for while also using a little out of the box thinking.


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« Last Edit: May 20th, 2016 at 7:53pm by JLouis »  

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Re: NOE 321187
Reply #20 - May 24th, 2016 at 6:45pm
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To put any speculation to rest, I ran this group buy, because I have always wanted this bullet to try and to have for my collection. If anyone doesn't know what it is, it is a copy of the 319323 Ideal, W.H. French designed bullet and a very accurate copy of it., I used Ideal's band diameters from a Ideal manual and the length was taken from Froggy's actual, sample bullets, from his mold, cast in my 22/1 alloy.   

This is NOT a new design to "beat the competition", this is a original bullet mold and as far as I can tell, the first full spitzer mold, ever produced. It was cataloged on or before the Ideal #22 (1912) Handbook was published.

It was designed for the 16 twist rifles of the day and I will use it in my 16 twist HW, with a Douglas, .321 x .315 barrel.

I haven't got my mold yet, as I just got back from Spokane and have to order it.

Since so many on this form, bought it, it would be nice to get accuracy results with both old and newer rifles so, we can see what the ODG might have done with it. Both with smokeless and BP and duplex.

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Re: NOE 321187
Reply #21 - May 24th, 2016 at 8:07pm
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Its nice to see you were able to make it Tommy's Frank and I hope you had an enjoyable time.

JLouis
  

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