Cast Bullet Ogive Shapes - Why ?

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Last Post 06 August 2019

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Slug Gun posted this 02 August 2019

I’m new to shooting cast bullets in rifles and came from the long range jacketed bullet shooting game (600 to 1,000 yards). Looking at some of the equipment lists in “The Fouling Shot” and searching mold maker’s websites; I’m surprised that there aren’t more spitzer or high ballistic coefficient ogive style bullets being used. Looking at the .30 cal. equipment list , most are shooting very blunt ogive shaped bullets at velocities approaching and exceeding 2,000 FPS. Why the blunt shape more then a more pointed ogive bullet. Is it because it is difficult to manufacture molds with a spitzer shape ? Is it more difficult to cast a spitzer shaped bullet ? Are the blunt nose bullets more accurate at cast bullet velocities then spitzer or round nose bullets ? Do the long nose blunt bullets allow more bearing surface then a pointed bullet ?

What am I missing here ?

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Larry Gibson posted this 06 August 2019

"But the implication that a bullets driving bands are being sized down from whatever lube is being used has a large effect on the CBA's goal for accuracy and may be why it hasn't progressed much in the past couple of decades."

Excellent point.

"Most contributors here say lube doesn't effect accuracy too much." I also have to disagree with them. Over the years I've compared different lubes to see if there was an accuracy difference and found out there usually was. Certain bullet designs and probably barrels seem to have their preferences. Sometimes not so much difference but other times a noticeable difference. I also conducted an extensive HV test of 13 or so different lubes and found out there was a real difference there.

Perhaps 45 2.1 is on to something regarding "viscosity" as I've always, almost invariably, found the softer lubes to give the best accuracy.

LMG

Concealment is not cover.........

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Ross Smith posted this 06 August 2019

getting back to the original topic, one of the bullets was described as a good 600 yd bullet. I seen references like that before. Is this bullet no good at 100 yds? If so why is it accurate at 600?

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Eutectic posted this 05 August 2019

The early spire point designs tried to emulate jacketed bullets. This was not successful as there was not sufficient full diameter body to provide support. Boat tails are another failure as with maximum velocity we need a gas check. Here are a couple of long ogive bullets I designed and Veral Smith made for me. The article is in press in the FS, due out sometime soon

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45 2.1 posted this 05 August 2019

But the implication that a bullets driving bands are being sized down from whatever lube is being used has a large effect on the CBA's goal for accuracy and may be why it hasn't progressed much in the past couple of decades. Most contributors here say lube doesn't effect accuracy too much. Most of the stick lubes are fairly stiff and viscous. Many here are just lubing the GC shank area or it and the groove in front of it. The problem with lube purging comes to mind also. So, just what is everybody using? So:

Could it be that the stiff lubes that everyone is using are too stiff and are detrimental to better accuracy?

I myself make my own lube, a small pea sized ball melts almost instantaneously with a pass of a butane pencil torch. Other commercial and cast lube makers I've tested do not. Is this one of the problems plaguing shooters now? I haven't seen the band reduction problem... maybe because of the lube I'm using. I certainly am not going to be using any lube that causes this problem, especially since the evidence has been shown.

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David Reiss posted this 05 August 2019

Larry, cool it. Some of your comments are not necessary. I don't want to ban members again for bickering.

David

Thank you joeb33050......much appreciated.

There you go 45 2.1; https://castbulletassoc.org/thread/12512-hv-bullet-damage-interesting-results/ a thread on this forum discussing the subject. BTW, those "mentioned forums" do exist and are active discussing cast bullet shooting.....especially the CBF..... You've been telling us you've not got a "digital camera" for 10+ years as an excuse why you can't post any pictures or test results......most of us actually have been using phones to take pictures for many years now so the max effective range of that excuse is near zero. As John said......45 2.1 said.....well yes you do say a lot of things, some results posted would be nice.......

And as usual you attempt to further obdurate the issue by bringing up some supposed difference between European and American specification......where does that enter this discussion? No it doesn't because naked lubed cast bullets shot out of those will be swaged down in European bores just as correspondingly smaller than groove diameter as they are in American bores regardless of any difference in "specifications"..

LMG

David Reiss - NRA Life Member & PSC Range Member Retired Police Firearms Instructor/Armorer
-Services: Wars Fought, Uprisings Quelled, Bars Emptied, Revolutions Started, Tigers Tamed, Assassinations Plotted, Women Seduced, Governments Run, Gun Appraisals, Lost Treasure Found.
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45 2.1 posted this 04 August 2019

Thanks Joe!

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Larry Gibson posted this 04 August 2019

Thank you joeb33050......much appreciated.

There you go 45 2.1; https://castbulletassoc.org/thread/12512-hv-bullet-damage-interesting-results/ a thread on this forum discussing the subject. BTW, those "mentioned forums" do exist and are active discussing cast bullet shooting.....especially the CBF..... You've been telling us you've not got a "digital camera" for 10+ years as an excuse why you can't post any pictures or test results......most of us actually have been using phones to take pictures for many years now so the max effective range of that excuse is near zero. As John said......45 2.1 said.....well yes you do say a lot of things, some results posted would be nice.......

And as usual you attempt to further obdurate the issue by bringing up some supposed difference between European and American specification......where does that enter this discussion? No it doesn't because naked lubed cast bullets shot out of those will be swaged down in European bores just as correspondingly smaller than groove diameter as they are in American bores regardless of any difference in "specifications"..

LMG

Concealment is not cover.........

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joeb33050 posted this 04 August 2019

https://castbulletassoc.org/thread/12512-hv-bullet-damage-interesting-results/

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45 2.1 posted this 04 August 2019

Perhaps instead of me re-posting all the time for 45 2.1 whims he could post pictures of his own recovered bullets. Or maybe even do a search of past posts. Or anyone is free to take a naked lubed bullet load and shoot several into a medium where the bullets can be recovered relatively undamaged and then measure the diameter. Perhaps omeone else can conduct a similar test and report back?
Is there a search engine for this forum?

Some of the mentioned forums results seem to be questionable as the don't exist now or don't have shooting as a focus. Since others besides me have questioned what you've said, a link to these tests and pictures would be appreciated by all of us, if it wouldn't be too much trouble. I have done the tests numerous times and did know the groove diameter of the tested firearms.... the result didn't show what you said. I can't show the result as I didn't have digital camera equipment (and still don't) of those tests. There is the problem of 30 caliber bore and groove dimensions. The European rifles have a lot tighter specification than American and we certainly don't run a tight spec on that especially when one can measure barrels with specs of .3075" to 0.3095" groove diameters from American made rifles I have measured. Normal 0.308" groove dimensions don't mean much when the rifle in question doesn't have that. Also this forum doesn't seem to have search capability.

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45 2.1 posted this 04 August 2019

Is this the type of ogive bullet that you are referring to?

Pretty well............. The most often cussed/discussed seems to be the Lyman 311413. All the old mold makers made a version of it it seems, I have the Belding and Mull version myself. Lyman made a lot of molds in that number with several cherrys and the normal variations. The older Lyman manuals recommended it for 600 yard shooting. One version I measured years ago had a nose that actually touched the lands, most do not.

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John Schauf posted this 04 August 2019

Is this the type of ogive bullet that you are referring to?

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John Schauf posted this 04 August 2019

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Larry Gibson posted this 04 August 2019

It was all posted on another forum by goodsteel and Lars (who makes White Label Lubes) who conducted an extensive bullet recovery test. I also reported on goodsteel's forum, the CBF forum and on this forum the results of my HV bullet recovery test.....including numerous pictures. Others have reported recovering bullets that were little damaged yet of less than groove diameter.

"Under what condition of pressure/velocity/alloy have you observed bullets getting smaller? What mechanism would do such a thing? I ain't swaging."

I ran my tests recovering HV 30 XCB bullets at 300 yards shot into wet news print with muzzle velocity of 2900 fps and impact velocity at 1900 +/- fps. Goodsteep and Lars conducted their testing at velocities of mid teens to 2600 fps. They built a sawdust bullet trap.

Yes it is swaging. The naked lubed bullet rides on a thin layer of lube in the bore. The lube is not compressible (laws of hydraulics is what would do such a thing), thus the bullet is swaged down to the groove diameter plus the layer of lube. It ain't rocket science just hard to conceive at first.......just have to think about it is all...... the bullet is swaged down to the bore plus the layer of lube it has to travel over.

I have observed the smaller than groove diameter phenomenon at very low end pressures in 1000+/- fps loads up to the mentioned 2900 fps load at 50,000 psi. That's actual measured psi btw, not questimated.

Perhaps instead of me re-posting all the time for 45 2.1 whims he could post pictures of his own recovered bullets. Or maybe even do a search of past posts. Or anyone is free to take a naked lubed bullet load and shoot several into a medium where the bullets can be recovered relatively undamaged and then measure the diameter. Perhaps omeone else can conduct a similar test and report back?

Is there a search engine for this forum?

LMG

Concealment is not cover.........

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Maven posted this 04 August 2019

TRK/CW, Do you know of any feedback, i.e., results, loading information about that group buy CB?

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max503 posted this 04 August 2019

No problem. That's what J-B Weld is for.

R.

I just bought a Lee 102 grain mold for my 380 and I'm needing a top punch. I'll have to try the JB.

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TRKakaCatWhisperer posted this 03 August 2019

The whole idea for that one was low drag and LONG rage accuracy. I met with Jay once at his home (on my way from Virginia to MNPLS). I must say he made a respectable wine.

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TRKakaCatWhisperer posted this 03 August 2019

Maven - that was Jay Downs/Aladdin and myself. I did the cad work and had many discussions with some folks that were in the business of ballistic design/shape/form. Yes, it started with the Speer bullet. I contracted with a local machine shop to make the nose-punches as well. Still have my mold and have picked up 2 or 3 rare long-spire-boattail molds made years ago.

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Maven posted this 03 August 2019

45 2.1, Didn't you design a spire point group buy CB on the Boolits site (Jay Downs/Aladdin honcho'ed it) years ago? Wasn't it a copy of a Speer jacketed target bullet? I purchased that group buy mold (don't remember what I used for a top punch though), but didn't get stellar accuracy from it at "normal" CB velocity, i.e., ~1,750 fps in my case. However, on the suggestion of a Boolits member, I tried a healthy, but by no means excessive charge of IMR 4350 and things improved immediately. As I had more accurate CB designs molds available, I sold that mold to a CBA member.