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Yawing 32-40 bullets (Read 19524 times)

frnkeore Frequent Elocutionist Offline Posts: 7674 Location: Central Point, OR 97502 Joined: Jun 16^th, 2010	Re: Yawing 32-40 bullets Reply #30 - Mar 11^th, 2017 at 2:36pm	Print Post
	Regarding this subject, I think that newer shooter may be confusing stability with accuracy. Stability is a ability for a bullet to maintain a inline path w/o yaw or tumbling. Accuracy is the ability to group bullets as close together as possible and that entails many more variables of which stability is just one of them. You can also have marginal, even poor stability and very good accuracy as this 6c target shows. It was shot at Modesto in a match. 1/2 gr increase of the powder charge straighten them up for the next match. Frank

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Travelor Full Member Offline Posts: 132 Location: Central Arkansas Joined: May 5^th, 2008	Re: Yawing 32-40 bullets Reply #31 - Mar 12^th, 2017 at 10:14am	Print Post
	calledflyer wrote on Mar 10^th, 2017 at 1:18pm: Well, Travelor, have you tested the advice to increase the speed of the bullet? Did it reduce or eliminate the yawing? I get it a little now and then when experimenting, and if the bullet is at all suitable that speed increase will fix it. Not always retaining the same accuracy, though. Sometimes a little wiggle in a bullet's rear end is as pleasing as a wiggle in a shapely girl. Not yet, but have the charges increased in .2 grain increments and am waiting for suitable weather to test. Also spoke with Paul Shuttleworth and he also recommended increasing the powder charge. Thanks again guys!


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frnkeore Frequent Elocutionist Offline Posts: 7674 Location: Central Point, OR 97502 Joined: Jun 16^th, 2010	Re: Yawing 32-40 bullets Reply #32 - Mar 12^th, 2017 at 4:03pm	Print Post
	Quote: But the gyroscopic stability calculation does not evaluate dynamic stability which is related to nose shape, center of gravity and length of time that drag is exerted and the amount of time over and below speed of sound. And this program does: (You need to *Login* or *Register* to view media files and links) Frank

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JLouis Frequent Elocutionist Offline Posts: 10625 Joined: Apr 8^th, 2009	Re: Yawing 32-40 bullets Reply #33 - Mar 12^th, 2017 at 4:13pm	Print Post
	Why would you use 1600fps. as an example that is really pushing the pressure limits on a 32-40 should a new fellow not knowing any better actually go out and try to reach it?

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frnkeore Frequent Elocutionist Offline Posts: 7674 Location: Central Point, OR 97502 Joined: Jun 16^th, 2010	Re: Yawing 32-40 bullets Reply #34 - Mar 12^th, 2017 at 4:30pm	Print Post
	Not to worry, John. This is what my 32/40 did in Modesto at 100 yd, using JSL lube and 16.1 gr 4227. The reason that there are 12 shots in the group, is because Barry's M43 had to be rebooted and because of that, there was a gap in the string, too. I was not holding for conitions, just getting the shots of for the chrono. The 16.5 gr, 5 shot group was with the 320366 lyman (185 gr) and it was exceeding 1600 fps. Frank

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JLouis Frequent Elocutionist Offline Posts: 10625 Joined: Apr 8^th, 2009	Re: Yawing 32-40 bullets Reply #35 - Mar 12^th, 2017 at 4:32pm	Print Post
	Verticle dispersion of 2 inches + and horizontal of 21/2 inches + no matter how many centers one lucked into is a prime example of unsatbity as the target and bullet holes clearly shows. A little tip at times can provide excellent accuracy but that is allot more than just a little tipping. If one cannot get his verticle and horizontal dispersion consistently down to about 1 inch tip or no tip he still has quite a ways to go in his laod develolment if he plans to become somewhat competitive.

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JLouis Frequent Elocutionist Offline Posts: 10625 Joined: Apr 8^th, 2009	Re: Yawing 32-40 bullets Reply #36 - Mar 12^th, 2017 at 4:44pm	Print Post
	Flirty with disater in my book, a 185gr. bullet and 1546fps. is not the same as a 205gr. and 1600fps. especially when taking the action and tenon size being used but your the expert on such things so I will back on out of here as I don't want any part of someone getting hurt or destroying a nice original rifle.
	« Last Edit: Mar 12^th, 2017 at 5:20pm by JLouis »
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frnkeore Frequent Elocutionist Offline Posts: 7674 Location: Central Point, OR 97502 Joined: Jun 16^th, 2010	Re: Yawing 32-40 bullets Reply #37 - Mar 12^th, 2017 at 5:22pm	Print Post
	John, The 12 shot 16.1 gr 4227 group was shot when you were present. It's a 206 gr PJ bullet. The 185 gr bullet was with 16.5 gr 4227. Quote: Verticle dispersion of 2 inches + and horizontal of 2 1/2 inches (not that it matters but it 1 3/4 x 2 5/8) + no matter how many centers one lucked into is a prime example of unsatbity as the target and bullet holes clearly shows. A little tip at times can provide excellent accuracy but that is allot more than just a little tipping. If one cannot get his verticle and horizontal dispersion consistently down to about 1 inch tip or no tip he still has quite a ways to go in his laod develolment if he plans to become somewhat competitive . How many time have you scored over 246 6c with straight on bullet holes and how many times have you scored less than that with your short flat nosed bullets at one of the hardest ranges to shot good scores in the nation? I never said anything about it being stable, just that good stability doesn't have to be present for good accuracy. If every one had 1" x 1" dispersion, what a bunch of boring 250's we would have I've only shot there twice and I do thank Barry, very much, for him providing the use of his M43. Frank PS Check match results across the nation and tell us who and how many people shoot under 2 5/8 10 shot groups.
	« Last Edit: Mar 12^th, 2017 at 5:33pm by frnkeore »
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JLouis Frequent Elocutionist Offline Posts: 10625 Joined: Apr 8^th, 2009	Re: Yawing 32-40 bullets Reply #38 - Mar 12^th, 2017 at 6:32pm	Print Post
	Frank the 25 Ring is 11/2 inches in diameter and the wind and mirage can push you an easy three inches. If you can not get your verticle and horizontal dispersion down to at least 11/2 inches there are no hopes of ever shooting a 250 but by luck just do the math! Getting it down to one inch and where it should be does make shooting 250's easily boring as you made note of and of which I don't beleave you have yet do it only provides for a very small margin of error when playing the odds to ones best advantage. If you want to teach others how to become consistently competitive one and five eighths of an inch of verticle or horizontal dispersion will not fit into a one and half inch circle no matter how hard you try even if shooting in a vacum under perfect conditions! How one can proclaim shooting 250's to become easy and boring by consistently obtaining one inch of verticle and horizontal dispersion is well beyond most here including myself. But there are still some I guess who are maybe like yourself who still think fitting two plus inches into an inch and a half an easy thing to do so its best to just leave it at that and not worth arguing over the mathematics of it not just being so in an effort on my behalf to not discourage anyones hopes of being able to do so on a consistant basis and with such ease of which you have clearly stated it to be so.

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JLouis Frequent Elocutionist Offline Posts: 10625 Joined: Apr 8^th, 2009	Re: Yawing 32-40 bullets Reply #39 - Mar 12^th, 2017 at 7:00pm	Print Post
	Those across the Nation and now there are several who have shot 250's have not done so by simply getting their rifles to shoot 25/8 inch groups Frank they just don't simply fit into an 11/2 inch circle that I am aware of? But I can tell you in all honesty that Jerry Hartwig has his 25WCF shooting consistently well under a 25/8 inch groups at 200yds. and my 28-35SS has averaged 13 ten shot groups with an average of 1.42 at 200yds in various temps. and conditions and all though quite good for me still being a fairly new rifle it will even get better in due time as it can never get worse as I continue to make changes to improve on it.

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frnkeore Frequent Elocutionist Offline Posts: 7674 Location: Central Point, OR 97502 Joined: Jun 16^th, 2010	Re: Yawing 32-40 bullets Reply #40 - Mar 12^th, 2017 at 7:36pm	Print Post
	John, Get real. In the match that I shot that 246, your best target, was also a 246. Go back and look! In the 100 yard event, that same day, after upping my charge 1/2 gr, my small group at 100 was .336. Again, I only shot on your range one other time and you've consumed 64 lb of just 300MP their. Tell everyone how many 250's you've shot in a match at your range. Oh never mind, I'll tellthem, it's 0. Maybe you need to work on your dispersion! One lucky 5 - 5 shot group, (after trying muliple time in a few months) does not make a expert, sorry. I could add more about your scores but, I'll stop here. Talk fact and give up trying to put me down!!! Frank Hmmmmmmm, todays score, LOUIS 486-8. 28-35SS. Does that average 243 with some lucky c's? I think we need better dispersion, John. Sorry guy's, I'll end it right here.
	« Last Edit: Mar 12^th, 2017 at 7:50pm by frnkeore »
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SgtDog0311 Senior Forum Member Offline Posts: 391 Joined: Mar 19^th, 2014	Re: Yawing 32-40 bullets Reply #41 - Mar 13^th, 2017 at 11:55am	Print Post
	Schuetzendave wrote on Mar 10^th, 2017 at 8:19pm: Caliber 0.321 Inches Bullet Weight 164 Grains Bullet Length 0.85 Inches Barrel Twist 17.5 Inches/turn muzzle velocity 1400 fps Temperature 50 degrees Fahrenheit (59 is standard) Pressure 29.92 inches of mercury (29.92 is standard) Sg = 1.84 Caliber 0.321 Inches Bullet Weight 180 Grains Bullet Length 0.93 Inches Barrel Twist 17.5 Inches/turn muzzle velocity 1400 fps Temperature 50 degrees Fahrenheit (59 is standard) Pressure 29.92 inches of mercury (29.92 is standard) Sg = 1.57 Caliber 0.321 Inches Bullet Weight 200 Grains Bullet Length 1.09 Inches Barrel Twist 17.5 Inches/turn muzzle velocity 1400 fps Temperature 50 degrees Fahrenheit (59 is standard) Pressure 29.92 inches of mercury (29.92 is standard) Sg = 1.12 Sg shouldn't be less than 1.4 (bullet will tumble). If Sg is greater than about 2.0, you may gain some accuracy by going to a slower twist barrel. Dave, thanks for the extra numbers. Much of what is said here is over my head but I will note: In the June 2014 copy of The Single Shot Exchange Lee Shaver wrote an article on the Greenhill formula. I took the time to do some calculations then for whatever bullet I was drawing for Tom at Accurate back then and actually made myself revisit my 8th grade math… which is a difficult feat for me. And of course that doesn’t get you to an SG but rather it gets you to a twist rate. I only wish I had ordered that mould in a steel block now – or had Jim at BACo make me one up from his Saeco blocks. From what Shaver says the Greenhill used a “constant” of 150 with his formula: Twist = 150 x diameter sq'd / Length But Mr Shaver seemed to think a better swag at the constant was 135 for lower velocity cast applications. In that article he indicated if you wanted to get even closer 3.5 x the SqRt of velocity would tailor the formula to your bullet. I have not plugged the numbers into my .817 bullet and the velocity of my load but the result would give me a twist rate to compare with the actual twist in my two 32-40s.

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JLouis Frequent Elocutionist Offline Posts: 10625 Joined: Apr 8^th, 2009	Re: Yawing 32-40 bullets Reply #42 - Mar 13^th, 2017 at 12:30pm	Print Post
	Frank brings up a very valid point and I am quite happy he did as my performance for last Saturdays match was indeed severly lacking but the performance of my rifle was not. If I had done my part 250's were indeed very doable and the subject at hand is really about a rifles true capabilities. I have spent the time and effort to get my 28-35SS to become very capable of consistently putting 10 shots into an 11/2 circle or less and the 25 ring at 200yds. If I do not take full of advantage of those capabities during a match it is just simply a realistic and direct reflection on my limitied capabilities to properly adjust to the conditions for the day and no fault of the rifles. Yours Sincerely John Louis

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beltfed Frequent Elocutionist Offline Posts: 1827 Location: Central Wi Joined: Dec 20^th, 2007	Re: Yawing 32-40 bullets Reply #43 - Mar 13^th, 2017 at 5:48pm	Print Post
	Frank! John! PLEASE stop the pissing match! I respect you both, except for that! beltfed/arnie


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JLouis Frequent Elocutionist Offline Posts: 10625 Joined: Apr 8^th, 2009	Re: Yawing 32-40 bullets Reply #44 - Mar 13^th, 2017 at 7:23pm	Print Post
	Here is the long and short of it all I left here once and I do not plan on doing it again! My comments were directed at tipping, group size and accuracy pretty plain and simple. If Frank thinks it was directed at him personaly there is just simply nothing I can do it about. If I choose to reply to a post I have the freedom to do just that and they be directed to the group and not to Frank. If it is a reply that might go against his personal beliefs or personal findings he will just have to learn to deal with it or he could then choose to leave. I have no intrest in getting into anymore pissing matches with anyone and I purposely avoided the one he was obviously just trying to start of which I refused to respond to in a demeaning manor. My last post was clearly to and for the benefit of the group and should have simply been taken that way. If he chooses to carry on with his persoanl attacks don't include me in any of it any longer as was just trying to be done he is accountable for his own actions not me! Yours Sincerely John Louis

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