6mm Rem with DTAC 117 BN Bullets
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gme
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I'm running a 30" krieger barrel on my 6Rem, 7.5 twist, from my experience it seems that moly coating along with moderate velocities,3050-3100) seem to prevent bullet loss, the only bullets I've blown up have been uncoated,both Berger and DTAC's)BTW, have had friends try the 8 twist, dosent work all the time with the 115"s but works well with the 105-107's, the 117's I've seen were unacceptable with loose and crooked tips and I suspect that the high rpm's are occaisonally causing the tips to be flung off the bullets causing jacket damage and bullet failure, just a theory...
Gary Eliseo
Gary Eliseo
gme said:
The issue is the jacket. Perhaps they need to increase the weight of the bullet to 118-119 grains, reduce the mass of the lead in the core of the bullet, and go for a thicker jacket. As long as the length of bullet is unaltered it shouldn't affect the twist rate required to stablize it.
I would be curious to see what exactly the thickness of jackets are measuring in production lots and why the polymer tips are so poorly seated in many bullets. This could be a sign of a jacket that is far too thin in my instances at the ogive and while the barrel will keep the bullet together once it exits the muzzle the bullet's jacket is fatigued to the point where separation occurs in the first 10-20 yards without the support of the barrel. This is my hypothesis we would need to do series finite element analysis on the construction of the bullet to see what is really happening to it.
Robert,
What Jerry said was correct. I was there when 2 bullets from David's rifle vanished on their way to 1000 yds.
I'm sure David is going through some testing variations at the moment to find the cause and reason for such ill behavior.
I still think the idea of the Boron Nitride plated bullets is fascinating and should prove successful once all glitches are resolved. One of many suggestions I was able to perceive at the Rocky Mountain Palma matches was reducing the twist rate to better handle the slippery nature of such pill.
In the meanwhile, I've put my new 6XC reamer project on hold.
Andy
What Jerry said was correct. I was there when 2 bullets from David's rifle vanished on their way to 1000 yds.
I'm sure David is going through some testing variations at the moment to find the cause and reason for such ill behavior.
I still think the idea of the Boron Nitride plated bullets is fascinating and should prove successful once all glitches are resolved. One of many suggestions I was able to perceive at the Rocky Mountain Palma matches was reducing the twist rate to better handle the slippery nature of such pill.
In the meanwhile, I've put my new 6XC reamer project on hold.
Andy
Sako6555 said:
The issue of reducing the twist, is not going help. After all you need a specific number of revolutions per second or minute to create the proper amount of gryoscopic force for stabilization. The reduction of twist means that why it might reduce the actual physical friction and force required to drive the bullet inside the barrel itself the velocity will have to be higher to maintain the required gyroscopic effect to stablize the bullet in flight. This is a catch twenty-two, you decrease the internal barrel ballistic effects of friction and forces acting on the bullet but only find that in flight you're still stressing the bullet from excessive velocity to regain gryoscopic effective needed to stablize it. So I think the issue is bullet construction...
Donavan,
Thanks for your input ! I am glad that you have not had any problems with the 117 DTAC. I am assuming that you read the data I gave regarding two different rifles that are new with a small number of rounds down the bores .
Neither of those two rifles experienced bullet failure with the 115 DTACS naked . Velocities at the 3100 mark at that . However .............. both have suffered bullet loss when using the 117DTACS b/n .Granted the rifle with the more loose bore has only lost one and that at a fast rate of fire, 70 or so rounds down the bore and high ambient temperatures .
I could wish this problem isn't , but it is . Looking at the various experiences listed in this thread it is apparent that there is a problem . It is also , in my lowly opinion , a problem with the bullets . Not the bbls , not the twist , not the bbl length , ................just the bullets .
I would add that to me the bbl temp appears , in my mind , to have some effect in accelerating the failure rate .
I have no desire to point fingers or assign blame , simply to achieve a solution for the problem .
Also , if you want some more of these 117 DTACS b/n , I have a thousand of the second lot and 500 of the first lot . Will ship to you at cost plus shipping .
Jim Brown
Thanks for your input ! I am glad that you have not had any problems with the 117 DTAC. I am assuming that you read the data I gave regarding two different rifles that are new with a small number of rounds down the bores .
Neither of those two rifles experienced bullet failure with the 115 DTACS naked . Velocities at the 3100 mark at that . However .............. both have suffered bullet loss when using the 117DTACS b/n .Granted the rifle with the more loose bore has only lost one and that at a fast rate of fire, 70 or so rounds down the bore and high ambient temperatures .
I could wish this problem isn't , but it is . Looking at the various experiences listed in this thread it is apparent that there is a problem . It is also , in my lowly opinion , a problem with the bullets . Not the bbls , not the twist , not the bbl length , ................just the bullets .
I would add that to me the bbl temp appears , in my mind , to have some effect in accelerating the failure rate .
I have no desire to point fingers or assign blame , simply to achieve a solution for the problem .
Also , if you want some more of these 117 DTACS b/n , I have a thousand of the second lot and 500 of the first lot . Will ship to you at cost plus shipping .
Jim Brown
The solution seems to be simple enough. Some one needs to purchase a series of lots of 100 DTAC 117S Naked and Boron and a series of lots of DTAC 115's in the same manner. Since Accuracy isn't the issue here the fact that 115's and 117's need different freebore isn't going to be an issue too much. Some one needs to load up a series of bullets 20 from each lot should give us a decent stastical analysis. Now we what needs to be constructed is a series of screens about 4x4 feet placed at 20 yard intervals out 100 yards so that is five screens. These need to covered in thin paper. A really calm day is needed for this test. The chronograph is necessary as well. What I'm thinking is we test the threshold of the 6mm DTAC using the 115DTAC as baseline. First you shot 20 randomly choosen bullets from each lot of the 115 DTAC's at the standard accurate velocity nodes, than 20 more randomly choosen bullets at the higher velocity nodes and lower ones as well from each lot. This will all has to be recorded and graphed. Than you start the same process again with 117's if the jacket is blowing up we should see at if it is an internal issue that is if the bullet is some how damaged in the process of the rifle engraving the bullet should blow up at less than hundred yards. If the effect is rotation speed than the bullet again blow up when the gryoscopic effect is greatest ie maximum velocity. If the bullet is blowing up past 100 yards we know that something is occuring further along the flight envelop that will be a bigger issue. It could be some form of massive instablity that is caused in flight by jacket separation that caused an uncontrollable yaw or pitch motion in flight that breaks up the bullet. Any way we shake it the more barrels tested int his fashion and the more lots used the better off we will be able to talk about this problem.
ConnorExum said:
Conner , how gracious of you to volunteer ! : ) I will send you the bullets necessary for this test , jus t give me a address . This is for the 117 DTAC B/N bullets only thought you hav e to supply the 115 DTACS.
A test as you suggest would be good, but who has the time ?
Another thing that has come to my attention regarding the 117 DTACS with the boron nitride coating is that they do not appear to be coated in a even manner , it is a bit spotty to the naked eye . Perhaps there is a thing happening at the molecular level that mere eyeballs cant see .
Anyone else out there have any hard data to share regarding these bullets ? Seems to me there is a real lack of info for such a potential frontrunner in the 6 mm bullet lineup . I mean , .600 bc with 117 gr. weight , why is there no more interest or experience than is currently observable ?
Sure wish Richard Graves of Wildcat bullets could get his aluminum tipped 120 gr. 6mm bullets in th e pipeline soon , that could be a real eyeopener with RE 25 powder and some tweaking .
Jim B.
Jim, I suppose this is not hard evidence, but I have shot 500 DTAC 117 Boron Nitride bullets through my 6xc Kreiger one in seven and a half twist 30 inch barrel and no blown up bullets and very good accuracy. That finished my first box of bullets and a few days ago I started on my second box of 500. I shot 15 bullets out of this second box through a 6CM chambered Kreiger barrel again one in seven and a half twist but this time a 32 inch barrel. Those 15 rounds again were extremely accurate at 600 yds. MY muzzle velocities are in the 2990 range. So far I have not noticed any spotty coating on the bullets, but I will pay more attention now.
The fact that some folks had bullets with bent and missing tips and others had bullets blow up seems to indicate to me that certain lots of these bullets do have a problem. I just ordered another 500 of the lot that has been working well in my rifles. I am hoping my luck holds. I would expect Sierra and Mr.Tubb are investigating why some of these bullets are being returned.
Bob
The fact that some folks had bullets with bent and missing tips and others had bullets blow up seems to indicate to me that certain lots of these bullets do have a problem. I just ordered another 500 of the lot that has been working well in my rifles. I am hoping my luck holds. I would expect Sierra and Mr.Tubb are investigating why some of these bullets are being returned.
Bob
I have avoided posting on this subject because I do not want to seem biased regarding the bullet that is being discussed. Having said that I am reading several things that I feel compelled to address. In the interest of assisting those in the shooting sports I will add my thoughts.
As many of you know we have been studying the bullet failure issue for many years. We have collected a tremendous amount of information on this subject such as real world test data from multiple sources, extensive and highly technical material stress modeling, numerous detailed reports of bullet failure occurances and seemingly endless suggestions on what is believed to be the true root cause.
I recently provided a full report on the true root cause of bullet failures. If you want a copy please email me at eric.stecker@bergerbullets.com. It was a long report so I will sum up by saying the most common cause for bullet failure to reach the target is friction generating heat which gets hot enough to melt the core. This is most commonly observed by seeing what is described as a "puff" of smoke. The puff is actually molten lead. We have been able to prove that the core melts with a number of different tests. ,There are other causes of bullet failure but heat melting the core is the most common and the reason I believe that the 117 gr failed)
The reason why the heat becomes high enough to melt the core is not a simple black and white issue. This is why bullet failures occur infrequently and randomly. ,Some report never having a failure while others have experienced very few failures while still a few other experience many failures) As all of you can see from this thread bullet failures occur in bullets made by every manufacturer. This further proves that the "reason" cannot be one simple thing like "thin jackets". There is no one single cause of bullet failures due to excessive heat.
The truth is that each component in the rifle and the ammo varies to a degree that does influence performance in an inconsistent manner from rifle to rifle. The key to solving the bullet failure problem is to put together a combination that keeps the friction down to the point where the bullet does not over heat. It would be nearly impossible for anyone to say that "all you need is XYZ barrel and ABC bullet and you will never have a problem." It is clear that under the right,or wrong) conditions any combination can cause bullet failures.
I made several suggestions to eliminate bullet failures in my report and will not go into them again as the suggestions are numerous and lengthy,if you want to see them send me an email). At Berger we are working on making the bullets able to withstand greater level of heat but all shooters need to keep something very important in mind. We are at the point today where barrels are long, velocities and pressures are high as a result of the desire to get a flatter trajectory. If the bullets get "tougher" it is inevitable that the bullet delivery system will become harder on the bullet yet again in an attempt to achieve even flatter trajectory. I doubt that any bullet design could be tough enough to withstand endless advances toward shooting flatter.
I have seen a few folks say it is the bullets fault. I disagree and say that it is rather the fault of a normal desire to push faster and flatter in rifle shooting. Everything has its limits. When a group of components are pushed to their limits something is going to give. Since the bullet is the item that goes through the target it is natural to blame the bullet when it fails to go through the target. It is wiser however to look at the entire delivery system and ask yourself "have I pushed this system too far?" How you handle this question will determine your level of success and your number of bullet failures.
Regards,
Eric
As many of you know we have been studying the bullet failure issue for many years. We have collected a tremendous amount of information on this subject such as real world test data from multiple sources, extensive and highly technical material stress modeling, numerous detailed reports of bullet failure occurances and seemingly endless suggestions on what is believed to be the true root cause.
I recently provided a full report on the true root cause of bullet failures. If you want a copy please email me at eric.stecker@bergerbullets.com. It was a long report so I will sum up by saying the most common cause for bullet failure to reach the target is friction generating heat which gets hot enough to melt the core. This is most commonly observed by seeing what is described as a "puff" of smoke. The puff is actually molten lead. We have been able to prove that the core melts with a number of different tests. ,There are other causes of bullet failure but heat melting the core is the most common and the reason I believe that the 117 gr failed)
The reason why the heat becomes high enough to melt the core is not a simple black and white issue. This is why bullet failures occur infrequently and randomly. ,Some report never having a failure while others have experienced very few failures while still a few other experience many failures) As all of you can see from this thread bullet failures occur in bullets made by every manufacturer. This further proves that the "reason" cannot be one simple thing like "thin jackets". There is no one single cause of bullet failures due to excessive heat.
The truth is that each component in the rifle and the ammo varies to a degree that does influence performance in an inconsistent manner from rifle to rifle. The key to solving the bullet failure problem is to put together a combination that keeps the friction down to the point where the bullet does not over heat. It would be nearly impossible for anyone to say that "all you need is XYZ barrel and ABC bullet and you will never have a problem." It is clear that under the right,or wrong) conditions any combination can cause bullet failures.
I made several suggestions to eliminate bullet failures in my report and will not go into them again as the suggestions are numerous and lengthy,if you want to see them send me an email). At Berger we are working on making the bullets able to withstand greater level of heat but all shooters need to keep something very important in mind. We are at the point today where barrels are long, velocities and pressures are high as a result of the desire to get a flatter trajectory. If the bullets get "tougher" it is inevitable that the bullet delivery system will become harder on the bullet yet again in an attempt to achieve even flatter trajectory. I doubt that any bullet design could be tough enough to withstand endless advances toward shooting flatter.
I have seen a few folks say it is the bullets fault. I disagree and say that it is rather the fault of a normal desire to push faster and flatter in rifle shooting. Everything has its limits. When a group of components are pushed to their limits something is going to give. Since the bullet is the item that goes through the target it is natural to blame the bullet when it fails to go through the target. It is wiser however to look at the entire delivery system and ask yourself "have I pushed this system too far?" How you handle this question will determine your level of success and your number of bullet failures.
Regards,
Eric
M700 said:
Eric , I dont think I could agree with you more . I am also grateful for your ability and willingness to post in such a concise fashion .
Now , do you want me to send you some 117 DTACs to play, ummm , pardon me , experiment with ? Probably a silly question as I expect you have your own .
It really doesnt matter to me who makes the bullet , just want to know what is going on when they fail. As I think you were saying , " they will all fail if put in a recipe that is out of their design limits " , my quote , not yours .
So , what about a 120 gr vld for the mighty 6MM in its various conformations ?
Jim B.
Jimm,
I appreciate your post and want to respond not just to you but so that others can understand where I am coming from.
It is my opinion,based on some research) that there are enough shooters for all of the bullet makers,and all component makers) to make a living. This is partially why we sell J4 Jacket to any custom bullet maker who wants to use them. I don't make bullets so that I can defeat Sierra or anyone else. I love what I do. I was exposed to bullet making in 1990 when I went to work for Walt. When I say that he taught me everything I know this goes beyond bullet making.
Walt has a strong belief in the support and growth of the shooting sports. This comes from a genuine love of shooting. He has helped many bullet makers and shooters get more out of their experience. His attitude on this subject is infectious and having been exposed to it for 17 years I can say that I share his beliefs.
If I can help a shooter with a problem that results in their increased level of enjoyment with shooting I will do so. I frankly don't care whose product they are using. We have plenty of back orders and sales to pay the bills so I am not worried that by helping shooters who use other bullet makers we will lose sales. We make a good bullet and folks will continue to use products they can rely on and since few shooters buy only one brand of bullet this is further reason why I am not concerned.
Sierra is a good bullet company and I have described them many times as the most successful large bullet making company in the world. The reality is that our goals are different. Their focus is volume and price while they manage to make good bullets. Our focus is the producing bullets with the highest level of consistency while we manage to make some volume at a reasonable price. It is a credit to Sierra that they make bullets that are good enough to compete with us and it is a credit to Berger that we make enough bullets to become as well known as Sierra. All of this is good for the shooting sports and neither company will ever drive the other out of business.
I don't have any of the 117 gr. I picked this bullet to be a failure based on what we know to be true about very heavy 6mm bullets,we will not be making a 120 gr
but I do have several boxes of Sierras. I also have Sierra's product poster over my desk. Both of our companies learn a great deal from each other but at the end of the day we will still pursue our specific goals as best we know how.
Regards,
Eric
I appreciate your post and want to respond not just to you but so that others can understand where I am coming from.
It is my opinion,based on some research) that there are enough shooters for all of the bullet makers,and all component makers) to make a living. This is partially why we sell J4 Jacket to any custom bullet maker who wants to use them. I don't make bullets so that I can defeat Sierra or anyone else. I love what I do. I was exposed to bullet making in 1990 when I went to work for Walt. When I say that he taught me everything I know this goes beyond bullet making.
Walt has a strong belief in the support and growth of the shooting sports. This comes from a genuine love of shooting. He has helped many bullet makers and shooters get more out of their experience. His attitude on this subject is infectious and having been exposed to it for 17 years I can say that I share his beliefs.
If I can help a shooter with a problem that results in their increased level of enjoyment with shooting I will do so. I frankly don't care whose product they are using. We have plenty of back orders and sales to pay the bills so I am not worried that by helping shooters who use other bullet makers we will lose sales. We make a good bullet and folks will continue to use products they can rely on and since few shooters buy only one brand of bullet this is further reason why I am not concerned.
Sierra is a good bullet company and I have described them many times as the most successful large bullet making company in the world. The reality is that our goals are different. Their focus is volume and price while they manage to make good bullets. Our focus is the producing bullets with the highest level of consistency while we manage to make some volume at a reasonable price. It is a credit to Sierra that they make bullets that are good enough to compete with us and it is a credit to Berger that we make enough bullets to become as well known as Sierra. All of this is good for the shooting sports and neither company will ever drive the other out of business.
I don't have any of the 117 gr. I picked this bullet to be a failure based on what we know to be true about very heavy 6mm bullets,we will not be making a 120 gr
but I do have several boxes of Sierras. I also have Sierra's product poster over my desk. Both of our companies learn a great deal from each other but at the end of the day we will still pursue our specific goals as best we know how.Regards,
Eric
Once again ,
My hat is off to you Mr. Eric Stecker , and, thanks to your own admission , to Mr. Walt Berger as well . He seems to have instilled the best parts of being involved in this sport in you ., or any any other for that matter ) . I love seeing credit given where it is due .
As far as the 120 gr. 6 mm bullet not being on you alls agenda ......... nuff said . I am not a bullet maker but do respect the expertise that comes from very successful bullet makers such as Berger.
The law of " diminishing returns " can not be circumvented ................ by anyone . So , any plans to offer a vld 115 grainer with a polycarbonate tip ? Also , if you would like to have some 117 DTACS from two different lots send me a email . I will ship them to you , 50 per lot ) at my cost . These are the B?N coated bullets I think , at least that is what I ordered . The reason for my uncertainty is that I am puzzled by their spotty appearance .
I also believe that there is " plenty work out there for all " . I practice it in my own business by giving my competitors names to those that want my sevices but I am not able to accomodate them .
The world is what we make it in our own small sphere of influence .
all the best ,
Jim Brown
My hat is off to you Mr. Eric Stecker , and, thanks to your own admission , to Mr. Walt Berger as well . He seems to have instilled the best parts of being involved in this sport in you ., or any any other for that matter ) . I love seeing credit given where it is due .
As far as the 120 gr. 6 mm bullet not being on you alls agenda ......... nuff said . I am not a bullet maker but do respect the expertise that comes from very successful bullet makers such as Berger.
The law of " diminishing returns " can not be circumvented ................ by anyone . So , any plans to offer a vld 115 grainer with a polycarbonate tip ? Also , if you would like to have some 117 DTACS from two different lots send me a email . I will ship them to you , 50 per lot ) at my cost . These are the B?N coated bullets I think , at least that is what I ordered . The reason for my uncertainty is that I am puzzled by their spotty appearance .
I also believe that there is " plenty work out there for all " . I practice it in my own business by giving my competitors names to those that want my sevices but I am not able to accomodate them .
The world is what we make it in our own small sphere of influence .
all the best ,
Jim Brown
Eric, would you mind sending me your report on bullet failures to mysticplayer@hotmail.com.
Bullet failure is very interesting to me.
Without reading your report but other post, I surmise that if bullet failure does occur in a match smooth barrel, lowering velocity and/or pressures should reduce bullet failure incidence?
If that is the case, then we really are reaching a point of diminishing returns given how projectiles are presently produced.
Bummer, a 120gr 0.7BC 6mm bullet going 3000fps was really on my Christmas list.
Thanks for you continued candor and openess. It DOES improve the sport.
Jerry
Bullet failure is very interesting to me.
Without reading your report but other post, I surmise that if bullet failure does occur in a match smooth barrel, lowering velocity and/or pressures should reduce bullet failure incidence?
If that is the case, then we really are reaching a point of diminishing returns given how projectiles are presently produced.
Bummer, a 120gr 0.7BC 6mm bullet going 3000fps was really on my Christmas list.
Thanks for you continued candor and openess. It DOES improve the sport.
Jerry
Jerry,
Asking shooters to lower velocity is like telling a muscle car owner to switch to a V-4. It is not exciting and many feel it is counter productive.
Here in lies the problem. You are exactly right than a bullet with a .700 BC going 3,000 fps is attractive,sexy frankly). I haven't calculated the drop and drift but I suspect that it would make any 300+ yard shooter's mouth drool.
Unfortunately, the delivery systems we use to shoot a heavy bullet 3,000 fps and the material,volume and type) used to make a heavy bullet are both subject to real world forces.
To make a high BC bullet you need a sleek design but it also has to include mass. Long bullet mean long bearing surfaces which creates more friction.
To shoot a heavy bullet fast many use 30"+ barrels which means more surface to heat the bullet. The bullet is hottest at the muzzle so every extra inch at the muzzle really makes a difference in relation to heat.
Long bullets also require faster twist rates. The faster the twist the more length,in linear inches) the rifling. The rifling is the point where the bullet gets the hottest.
Put these three things together and you get little puffs of smoke from 30 to 100 yards,or other variations of bullet failure).
The fact that bullet failure does not always happen is significant,in fact it happens rarely). It means that we must be on the edge with current set ups. Being on the edge must mean that it will take just a little to stay away from the edge.
I would not suggest that shooters look only to reduce velocity,even though this would solve the problem). The key is to reduce friction thereby reducing heat. I have listed several ways this can be done in my report. Some changes can be made right away while other require addressing the delivery system before it is put together.
I believe the key to successful shooting is to put together a combination you can be sure will work year round at any range and then get behind the trigger. Learning what you bullet will do in the wind is far more important toward success than squeezing 100 fps more velocity,no matter how much it improves trajectory).
The report is on the way.
Regards,
Eric
Asking shooters to lower velocity is like telling a muscle car owner to switch to a V-4. It is not exciting and many feel it is counter productive.
Here in lies the problem. You are exactly right than a bullet with a .700 BC going 3,000 fps is attractive,sexy frankly). I haven't calculated the drop and drift but I suspect that it would make any 300+ yard shooter's mouth drool.
Unfortunately, the delivery systems we use to shoot a heavy bullet 3,000 fps and the material,volume and type) used to make a heavy bullet are both subject to real world forces.
To make a high BC bullet you need a sleek design but it also has to include mass. Long bullet mean long bearing surfaces which creates more friction.
To shoot a heavy bullet fast many use 30"+ barrels which means more surface to heat the bullet. The bullet is hottest at the muzzle so every extra inch at the muzzle really makes a difference in relation to heat.
Long bullets also require faster twist rates. The faster the twist the more length,in linear inches) the rifling. The rifling is the point where the bullet gets the hottest.
Put these three things together and you get little puffs of smoke from 30 to 100 yards,or other variations of bullet failure).
The fact that bullet failure does not always happen is significant,in fact it happens rarely). It means that we must be on the edge with current set ups. Being on the edge must mean that it will take just a little to stay away from the edge.
I would not suggest that shooters look only to reduce velocity,even though this would solve the problem). The key is to reduce friction thereby reducing heat. I have listed several ways this can be done in my report. Some changes can be made right away while other require addressing the delivery system before it is put together.
I believe the key to successful shooting is to put together a combination you can be sure will work year round at any range and then get behind the trigger. Learning what you bullet will do in the wind is far more important toward success than squeezing 100 fps more velocity,no matter how much it improves trajectory).
The report is on the way.
Regards,
Eric
Thanks Eric.
As in all forms of racing, to finish first, first you need to finish.
I like your analogy of riding on the edge cause we are. I see that all cals have a point where going longer/heavier doesn't work. Things start to get finicky when twist rates faster then 7 are needed especially when higher velocities are used.
Also, larger bores allow for longer/heavier for cal bullets,higher BC) to be made successfully. I assume that is because you have a 'more material' to handle the forces.
Since core disintegration is suggested as the main cause leading to bullet failure, have you experimented using different materials or alloys besides pure lead for the cores?
From playing a little bit with casting, small changes in the alloy give significant changes both in the melting points and strength. how about a 'wheel weight' or #2 type alloy for the core?
Look forward to reading your report.
Jerry
As in all forms of racing, to finish first, first you need to finish.
I like your analogy of riding on the edge cause we are. I see that all cals have a point where going longer/heavier doesn't work. Things start to get finicky when twist rates faster then 7 are needed especially when higher velocities are used.
Also, larger bores allow for longer/heavier for cal bullets,higher BC) to be made successfully. I assume that is because you have a 'more material' to handle the forces.
Since core disintegration is suggested as the main cause leading to bullet failure, have you experimented using different materials or alloys besides pure lead for the cores?
From playing a little bit with casting, small changes in the alloy give significant changes both in the melting points and strength. how about a 'wheel weight' or #2 type alloy for the core?
Look forward to reading your report.
Jerry
Jerry,
We did explore the use of other lead alloys for core material to solve this problem. As it turns out pure lead has a higher melting point than alloys.
We did not explore materials other than lead simply because this has been pursued due to other influences. The need for a "green" non-lead bullet has pushed us into testing everything from bismuth to tungsten to powdered alloys of many types.
Even though we have seen successes relating to hunting bullet performance none of these materials comes close to producing the precision needed by competition shooters.
We are making some changes to two different bullets to see if this allows the bullets to sustain more heat. The first of these two bullets,6.5mm 140 gr VLD) has been made and is being tested. The second of these bullet,6mm 105 gr VLD) is delayed due to challenges faced in producing the modification in a way that maintains precision.
I am hopeful that we will be able to toughen up our bullets but am aware that tougher bullets will be pushed even harder. The true goal is to educate shooters that their are limits to what rifles can do.
Regards,
Eric
We did explore the use of other lead alloys for core material to solve this problem. As it turns out pure lead has a higher melting point than alloys.
We did not explore materials other than lead simply because this has been pursued due to other influences. The need for a "green" non-lead bullet has pushed us into testing everything from bismuth to tungsten to powdered alloys of many types.
Even though we have seen successes relating to hunting bullet performance none of these materials comes close to producing the precision needed by competition shooters.
We are making some changes to two different bullets to see if this allows the bullets to sustain more heat. The first of these two bullets,6.5mm 140 gr VLD) has been made and is being tested. The second of these bullet,6mm 105 gr VLD) is delayed due to challenges faced in producing the modification in a way that maintains precision.
I am hopeful that we will be able to toughen up our bullets but am aware that tougher bullets will be pushed even harder. The true goal is to educate shooters that their are limits to what rifles can do.
Regards,
Eric
Eric, thanks for the update on your continued R&D. Nice to see boundaries being tested.
Have you considered making bullets LIGHTER???
My thought is that if bullets become structurally unstable once they get too long/heavy, why not take a known design and make it lighter. That will allow that bullet to travel faster offering an increased in effective wind drift reduction.
Say a 6mm 107gr MK or 6.5 139gr Lapua. They are very stable designs. Can their cores have less lead or made of composite? I see that Barnes is trying to produce accurate bullets using their solid bullet design. That would provide a lighter bullet for the given physical shape.
Any chance this direction might work?
Jerry
Have you considered making bullets LIGHTER???
My thought is that if bullets become structurally unstable once they get too long/heavy, why not take a known design and make it lighter. That will allow that bullet to travel faster offering an increased in effective wind drift reduction.
Say a 6mm 107gr MK or 6.5 139gr Lapua. They are very stable designs. Can their cores have less lead or made of composite? I see that Barnes is trying to produce accurate bullets using their solid bullet design. That would provide a lighter bullet for the given physical shape.
Any chance this direction might work?
Jerry
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