MBTcustom
11-02-2015, 04:36 PM
Hello my friends. I would like to write, and give my opinion of what I have seen, read, witnessed, learned, and demonstrated while pursuing the goal of shooting cast bullets at high velocity, as well as share a few points of my progression of personal discovery in this discipline.
Many of you have participated and followed along with me since my arrival here in 2011, as well as the pursuit of others who were here before, and those who have joined in along the way.
This article would not be complete without an explanation of where I started and how I got here.
I was always a gun nut and I was always a hopeless do-it-your-selfer. I have been casting since I was an adolescent. My father may have been a little too consenting by teaching me how to cast and shoot when I was so young, as well as giving me free access to power tools, reloading components, and firearms, but he believed in freedom, and he wanted me to know what freedom really feels like, and he was successful in that undertaking.
I made my first pistol when I was 14 years old (I still have it) and it used black powder to shoot 35 caliber rifle bullets (358318). Over the next few years, I experimented with quite a few of my father’s molds, shooting quite a bit of 30-30, 35 Remington, 45ACP, and 357Magnum. In truth, I doubt I have ever bought and used a single box of store bought ammo for those calibers (except 30-30 once when I needed brass).
After shooting thousands of rounds of these, I discovered high power bolt action rifles, and the accuracy and precision that could be had from my hand loads using jacketed bullets. Very quickly, I decided that cast bullets were best suited to pistol ammunition, while jacketed bullets in the green box, were very worth the cost for the speed and accuracy obtained from them.
Speed became the thing I enjoyed most. Getting the bullet to the target as fast as possible (within the bounds of safety) was what I liked, but I would never go below 30 caliber. My trusty 30-06 was great fun to shoot, and 1/2MOA was normal, but the speed just wasn’t there, and the recoil was no issue for me at all, so I considered buying something with a little more to offer, and began casting my wandering eye towards the 30 caliber belted magnums. After careful consideration, I landed on 300 Winchester Magnum as the very best next step up, and I bought a Remington 700 BDL in this caliber.
Over the next couple years, two things happened that changed the course of my pursuits: 1. I burned out the barrel on that rifle, and 2. I became a father.
Any of you who ever started a young family know what having a child does to your ammunition fund, and my case was no different. When I finally got back to my shooting, I found that my available income was greatly reduced from where it was before, and I started applying myself to find a way to shoot cast bullets in rifles more effectively, especially at HV.
I explained my plan to my father, and he mentioned that cast bullets had been shot at 3000fps in a 300WinMag using paper patched bullets. I started researching this paper patched bullet discipline, and it took no more than a few internet searches to find that the very best place on the internet to learn how to make paper patched smokeless cartridges was none other than our fair site castboolits.gunloads.com.
I joined the forum and started applying myself to learn how to do this. About the time I learned how to get paper patch working in my rifles, I realized that there was a vast amount of knowledge relating to shooting standard cast bullets that I had never learned, so I took a step back, pulled out the old molds, and started seeing how fast I could push them. I began building custom rifles almost immediately for the purpose as well as reloading equipment because this allowed me to experiment with quality that was a “known entity”, and gave me flexibility to change things as needed to achieve success.
I saw that there were several members on the forum who claimed to be able to shoot HV with cast bullets, and I did my best to understand all there is to know about shooting HV cast bullets.
You name it, if it had to do with shooting cast at high velocity, I made it, modified it, improved it, or used it. No holds barred, and I honestly tried to understand all the methods that claimed to deliver true HV accuracy.
I have observed several interesting things in this pursuit, and come to identify several methods which allow the possibility of shooting cast bullets to high velocities (2500FPS-3000FPS)
One method called “The low RPM method” utilizes custom slow twist barrels to achieve HV with accuracy.
Another method, I call “The high RPM method” which refers to shooting HV with standard 10-12 twist barrels.
There are two other views which are: paper patching, and “enhanced alloys”.
Of course there is a fifth view, that being the copper jacketed bullet (however, this will be mentioned only in passing).
The purpose of this thread is to describe my personal observations that may be of great value to those who are looking to understand the phenomena posted on castboolits.com and why it is difficult at times to reproduce in their own rifles. Please just try to take it with a grain of salt, and think about what I’m saying as I really don’t think any of the methods are doing anything that the others are not doing and I believe I understand how and why each of them work. Read on, and form your own conclusion. After all, it’s just “the opinion of that crazy goodsteel guy on cast bullets.” LOL!
Most of you have probably experienced the “RPM threshold” phenomenon where your cast bullet groups suddenly become minute of berm? I recently experienced this with one of my cast bullet rifles in 35XCB caliber. As long as I stayed below 2590FPS, my bullets would go into less than 2” at 100 yards, but when my loads crossed 2600, the group opened up to 10” or more. Just 10FPS between reasonable accuracy, and horrible accuracy. That’s the RPM threshold.
I started my pursuit of HV cast bullets from the “High RPM” point of view, and some have demonstrated pretty impressive shooting at 100 yards. The theory goes that if you match your alloy to your powder selection and barrel harmonics, you can push a relatively soft bullet at high velocity and maintain usable accuracy at long range. This method is anything but plug and play, and the best advice I have gotten is to just start shooting and figure out what your gun wants, and don’t be surprised if it takes 2000 rounds to get it right. I’m pretty much convinced at this point that advice is about as good as it gets, because it is a very specific condition for each particular rifle.
That said, I have no doubt that this is possible and has been done by numerous shooters for many years, and I think I know why it is possible as I will describe.
Another view that I have personally had excellent results with is the “Slow twist method” which simply negates the RPM threshold by using a new barrel in slower twist to make it so that the bullets never cross 140,000RPM so they do not ever get to the point where the groups open up dramatically. This method uses hard bullets made of classic alloys like Linotype, and Lyman #2 or COWW+2% tin water dropped. Speeds in excess of 3000FPS are easily achievable with barrels of 16 and 17 twist, and accuracy of 1.5MOA is possible and very common at ranges of 300 yards and probably further.
Another method that I have only dabbled in a little is the copper enhanced alloy method.
This method uses common alloys that have been spiked with copper to make them harder and tougher than anything that could be obtained with standard alloys. These bullets can be pushed to reasonably high velocity in excess of 2500FPS, although accuracy figures have escaped me. I get the feeling that it is similar to the other methods mentioned and probably well under 2MOA at 2500FPS. These bullets are too hard/tough to hunt with unless special precautions are taken such as hollow pointing them (my opinion only).
The final method I have looked into is paper patching. This is a very difficult pursuit of the perfect paper, the perfect wrap, the perfect alloy, and the perfect size of both the core, and the paper. However, it is demonstrated that it is very possible to achieve 1” groups at 3000fps with this method if you get it all right. Not too shabby if you can do it!
So that’s a brief overview of the four principle methods of HV cast bullets.
It is my opinion that all these methods function on the same principle, and have their own way of dealing with the thing that destroys cast bullet accuracy, and makes the RPM threshold a reality for so many people.
One of my favorite quotes from Albert Einstien says: “Once we accept our limitations, we can move past them” but it is my opinion that you have to know what your limitations are in the first place before you can either accept them, or move past them, and in the case of cast bullets, those limitations are very hard to see.
However, I believe I may have discovered what the limitations are, or something very close to it.
It happened back when I was planning to design the 30XCB bullet. I was attempting to do anything I could to see what actually happens when the bullet is engraved. Many have postulated that “the bullet gets damaged as it enters the rifling” but I could not understand why or how that is possible given that my rifles are very carfully designed and built to be perfectly concentric with chambers and throats that are perfectly aligned in every way, and my ammunition is built to the same exacting standards! I’m willing to admit that my bullets get damaged, but I take issue with the assertion that they are damaged in an way that is not perfectly concentric, and for the “damaged bullet” assertion to be true, they would have to be damaged on only one side, or in a misaligned fashion. That idea may hold up on your Wal-Mart Remington, but not on an MBT custom rifle! It’s impossible. Especially when you figure the fact that both the Wal-Mart Remington and the MBT flame out at exactly the same RPM? It just doesn’t hold water.
Add to that, the fact that I have recovered many bullets from the berm that were shot over the RPMTH and I saw no damage whatsoever (reading through the berm damage obviously). Not a single clue. Not a single hint of bullet imbalance based on visual inspection.
Of course, all of the bullets I observed were almost completely destroyed by the impact, so I needed a way to engrave the bullet like it would be as it was fired from the rifle with a full charge of powder.
After looking at a few pressure trace graphs, I thought that maybe I could use a small charge of fast burning powder to stuff the bullet into the rifling in a very similar fashion as it would be when a column of slow powder was ignited behind it, but without the subsequent buildup of pressure that accelerates it into warp speed and destroys it on the backstop. All I realty need is the first inch of bullet travel!
So I loaded one of my rifles with a very small charge of Bullseye powder and used it to shoot bullets into a bucket filled with wet sand.
I dug out the bullets as they were shot and scrubbed them gently with Dawn dish soap and a soft bristle brush in the sink, patted them dry, then observed them under magnification with a Bosch and Lomb microscope.
At first, I didn’t see anything that looked out of place. I saw a small amount of skid as the bullet engraved the rifling, but it was very concentric and even. Nothing was really standing out at me that would suggest an imbalanced bullet. I shot every 30 caliber mold design in the shop and carefully observed each of them.
The big light bulb moment came when I was observing a Lovern style bullet (311466) and I noticed that the rifling marks were not straight. It seemed that the bullet had become twisted when it gently impacted the wet sand in the bucket. I did the test again, and fired a few of that same bullet and looked at each one under magnification. They all exhibited the same slightly twisted look.
Suddenly, I realized what I was looking at! The bullet is a soft but strong material! What was happening was that the nose of the bullet engraved first and was commanded to spin by the rifling (as evidenced by the slight skid marks on the nose) while the base was still stationary. The base of the bullet caught up a little slower than the nose of the bullet, but when the bullet exited the muzzle, the bullet was strong enough to try to right itself in flight. Effectively doing a “dishrag twist” as it flies. There’s no way that centrifugal force is going ignore that vibration. At a certain point (I believe a VERY SPECIFIC POINT) the centrifugal force produced by the RPM is going to use that to overcome the stabilizing fact of the bullet’s spinning, and thus you have the RPMTH. I think I just popped the big red balloon the RPMTH was hiding behind.
Now, armed with this knowledge, I designed the 30XCB bullet. My objective was to make the rifling engrave the bullet right in the middle of the projectile, so that neither the nose nor the base had much chance to get engraved in a strange way (in fact, the nose has no opportunity at all, and nose slump is the only thing to worry about). The bullet was designed to be controlled by the rifling at all costs, to obtain as much BC as possible. It was designed to be balanced and to resist getting twisted head-on by being cast of strong alloys and being designed to survive every stage of the firing process. I believe the instant success of this bullet in all kinds of rifles across the board speaks to the fact that I was definitely onto something, and this bullet ended up being the golden ticket for the HV slow twist method.
Now, let’s apply this knowledge to the other methods of shooting HV cast bullets and see how it plays out.
HV with standard twist:
The hallmark 30 caliber bullet of the HV with standard twist crowd is the venerable Mi-Heck 30SIL. This bullet is everything the 30XCB is not. It has a progressive nose that is hourglass shaped and touches the crest of the ogive and the flare of the skirt just in front of a positively cavernous lube groove which renders a suspiciously thin core that connects the front of the bullet to the little base that holds the gas check. Given what I learned from the sandbox test (which this bullet was part of) this has to be the worst possible design in the history of HV shooting. Or is it? The fact is, wherever I would opt to make the bullet strong, the designer of the 30SIL designed in a weakness. Add to this the fact that the people who use this bullet to achieve unbelievably high velocities also insist on alloys that are very similar to those used in jacketed bullets (some even use range scrap exclusively) which have (amongst other properties) the ability to be twisted without springing back. In other words, the bullet engraves the rifling in the same twisted fashion and takes a set in that condition while still in the barrel which allows it to emerge as a stable projectile capable of much greater RPM, and theoretically, the harder you push it, the better it will like it, to a certain point.
Very few have been able to feel out the specifics of this method with even one rifle but it has been done numerous times.
Let’s consider paper patched bullets:
It is my belief that the paper jacket works just like a copper jacket. It protects the core of the bullet (our cast bullet in this case) from getting twisted by the rotational inertial as the bullet is being spun up and engraved. The patch itself allows the bullet to slip beneath it. This is one big reason you NEVER get good results if you glue the patch to the bullet. I’ve got news for you, once the bullet leaves the barrel, it doesn’t matter whether the patch stays attached, or comes of as confetti or paper dust. The main function of the paper patch is to help the bullet survive the first inch of acceleration, and get it out of the barrel in an “at rest” fashion, which it does quite well. The main problem with paper patching is getting a paper that protects the bullet well while keeping it perfectly aligned in the barrel, while not jacking with the flight as it is jettisoned at the muzzle. Basically, the paper does a great job of protecting the bullet, but it does an even better job of jacking up umpteen other things if you don’t do them right! Gotta TAME that rascal!
Copper enhanced alloys:
This is simply strengthening the bullet so much that it can resist getting twisted. That’s all I’m going to say about this method because I have not personally experimented with it enough but it can’t be left out of the discussion.
Now, I’ll tell you something else concerning jacketed bullets:
THEY DEAL WITH THE SAME ISSUE and they deal with it better than anything else.
I have cut open quite a few jacketed target bullets and XRF tested them to see what alloy is used in their cores. By and large, the alloy is pure, dead soft lead. That soft lead core, combined with a hard jacket made of perfect bearing material does something that our bullets cannot ever do. The cores twist and settle perfectly in that first inch of rifling and actually work like a shock absorber or a mercury recoil tube. That bullet leaves the muzzle as dead as a hammer with a hard jacket that will keep it together during enormous RPM and centrifugal force, and keep it safe all the way to the target up to 2 miles away. You can’t beat that with a wet squirrel.
This is what I have gleaned from the XCB project, and where my mind has been while I have been working towards HV cast bullets. I’m hoping people do not get the impression that there is a single way to do this, or that one way is smart, while others are dumb etc etc etc. Shooting HV cast bullets is a hard thing to do, and there are several ways to do it. One thing I think I can say with certainty is that it’s expensive. You have to pay the piper with time or money and there is no way around it.
Conclusions
So HV cast bullets is not economical which is the reason many people get into this sport. It’s still cool as all get out, and gets you lots of looks at the range from people who can’t shoot an AR-15 as well as you do your 30-06. LOL!
For me, it was about seeing what’s out there, how it works, and why it works. I’m satisfied with what I have learned so far, and what has been achieved. I hope everyone here has benefited greatly from the efforts of everyone who contributed to the HV cast bullet pursuits described (and at times fought over) by all involved. I can say it’s been the most exciting and grandest project I’ve ever attempted, and I appreciate having a place to tell people about it instead of the knowledge being mine alone and lost to anyone who might wish to do the same thing.
Thanks!
Many of you have participated and followed along with me since my arrival here in 2011, as well as the pursuit of others who were here before, and those who have joined in along the way.
This article would not be complete without an explanation of where I started and how I got here.
I was always a gun nut and I was always a hopeless do-it-your-selfer. I have been casting since I was an adolescent. My father may have been a little too consenting by teaching me how to cast and shoot when I was so young, as well as giving me free access to power tools, reloading components, and firearms, but he believed in freedom, and he wanted me to know what freedom really feels like, and he was successful in that undertaking.
I made my first pistol when I was 14 years old (I still have it) and it used black powder to shoot 35 caliber rifle bullets (358318). Over the next few years, I experimented with quite a few of my father’s molds, shooting quite a bit of 30-30, 35 Remington, 45ACP, and 357Magnum. In truth, I doubt I have ever bought and used a single box of store bought ammo for those calibers (except 30-30 once when I needed brass).
After shooting thousands of rounds of these, I discovered high power bolt action rifles, and the accuracy and precision that could be had from my hand loads using jacketed bullets. Very quickly, I decided that cast bullets were best suited to pistol ammunition, while jacketed bullets in the green box, were very worth the cost for the speed and accuracy obtained from them.
Speed became the thing I enjoyed most. Getting the bullet to the target as fast as possible (within the bounds of safety) was what I liked, but I would never go below 30 caliber. My trusty 30-06 was great fun to shoot, and 1/2MOA was normal, but the speed just wasn’t there, and the recoil was no issue for me at all, so I considered buying something with a little more to offer, and began casting my wandering eye towards the 30 caliber belted magnums. After careful consideration, I landed on 300 Winchester Magnum as the very best next step up, and I bought a Remington 700 BDL in this caliber.
Over the next couple years, two things happened that changed the course of my pursuits: 1. I burned out the barrel on that rifle, and 2. I became a father.
Any of you who ever started a young family know what having a child does to your ammunition fund, and my case was no different. When I finally got back to my shooting, I found that my available income was greatly reduced from where it was before, and I started applying myself to find a way to shoot cast bullets in rifles more effectively, especially at HV.
I explained my plan to my father, and he mentioned that cast bullets had been shot at 3000fps in a 300WinMag using paper patched bullets. I started researching this paper patched bullet discipline, and it took no more than a few internet searches to find that the very best place on the internet to learn how to make paper patched smokeless cartridges was none other than our fair site castboolits.gunloads.com.
I joined the forum and started applying myself to learn how to do this. About the time I learned how to get paper patch working in my rifles, I realized that there was a vast amount of knowledge relating to shooting standard cast bullets that I had never learned, so I took a step back, pulled out the old molds, and started seeing how fast I could push them. I began building custom rifles almost immediately for the purpose as well as reloading equipment because this allowed me to experiment with quality that was a “known entity”, and gave me flexibility to change things as needed to achieve success.
I saw that there were several members on the forum who claimed to be able to shoot HV with cast bullets, and I did my best to understand all there is to know about shooting HV cast bullets.
You name it, if it had to do with shooting cast at high velocity, I made it, modified it, improved it, or used it. No holds barred, and I honestly tried to understand all the methods that claimed to deliver true HV accuracy.
I have observed several interesting things in this pursuit, and come to identify several methods which allow the possibility of shooting cast bullets to high velocities (2500FPS-3000FPS)
One method called “The low RPM method” utilizes custom slow twist barrels to achieve HV with accuracy.
Another method, I call “The high RPM method” which refers to shooting HV with standard 10-12 twist barrels.
There are two other views which are: paper patching, and “enhanced alloys”.
Of course there is a fifth view, that being the copper jacketed bullet (however, this will be mentioned only in passing).
The purpose of this thread is to describe my personal observations that may be of great value to those who are looking to understand the phenomena posted on castboolits.com and why it is difficult at times to reproduce in their own rifles. Please just try to take it with a grain of salt, and think about what I’m saying as I really don’t think any of the methods are doing anything that the others are not doing and I believe I understand how and why each of them work. Read on, and form your own conclusion. After all, it’s just “the opinion of that crazy goodsteel guy on cast bullets.” LOL!
Most of you have probably experienced the “RPM threshold” phenomenon where your cast bullet groups suddenly become minute of berm? I recently experienced this with one of my cast bullet rifles in 35XCB caliber. As long as I stayed below 2590FPS, my bullets would go into less than 2” at 100 yards, but when my loads crossed 2600, the group opened up to 10” or more. Just 10FPS between reasonable accuracy, and horrible accuracy. That’s the RPM threshold.
I started my pursuit of HV cast bullets from the “High RPM” point of view, and some have demonstrated pretty impressive shooting at 100 yards. The theory goes that if you match your alloy to your powder selection and barrel harmonics, you can push a relatively soft bullet at high velocity and maintain usable accuracy at long range. This method is anything but plug and play, and the best advice I have gotten is to just start shooting and figure out what your gun wants, and don’t be surprised if it takes 2000 rounds to get it right. I’m pretty much convinced at this point that advice is about as good as it gets, because it is a very specific condition for each particular rifle.
That said, I have no doubt that this is possible and has been done by numerous shooters for many years, and I think I know why it is possible as I will describe.
Another view that I have personally had excellent results with is the “Slow twist method” which simply negates the RPM threshold by using a new barrel in slower twist to make it so that the bullets never cross 140,000RPM so they do not ever get to the point where the groups open up dramatically. This method uses hard bullets made of classic alloys like Linotype, and Lyman #2 or COWW+2% tin water dropped. Speeds in excess of 3000FPS are easily achievable with barrels of 16 and 17 twist, and accuracy of 1.5MOA is possible and very common at ranges of 300 yards and probably further.
Another method that I have only dabbled in a little is the copper enhanced alloy method.
This method uses common alloys that have been spiked with copper to make them harder and tougher than anything that could be obtained with standard alloys. These bullets can be pushed to reasonably high velocity in excess of 2500FPS, although accuracy figures have escaped me. I get the feeling that it is similar to the other methods mentioned and probably well under 2MOA at 2500FPS. These bullets are too hard/tough to hunt with unless special precautions are taken such as hollow pointing them (my opinion only).
The final method I have looked into is paper patching. This is a very difficult pursuit of the perfect paper, the perfect wrap, the perfect alloy, and the perfect size of both the core, and the paper. However, it is demonstrated that it is very possible to achieve 1” groups at 3000fps with this method if you get it all right. Not too shabby if you can do it!
So that’s a brief overview of the four principle methods of HV cast bullets.
It is my opinion that all these methods function on the same principle, and have their own way of dealing with the thing that destroys cast bullet accuracy, and makes the RPM threshold a reality for so many people.
One of my favorite quotes from Albert Einstien says: “Once we accept our limitations, we can move past them” but it is my opinion that you have to know what your limitations are in the first place before you can either accept them, or move past them, and in the case of cast bullets, those limitations are very hard to see.
However, I believe I may have discovered what the limitations are, or something very close to it.
It happened back when I was planning to design the 30XCB bullet. I was attempting to do anything I could to see what actually happens when the bullet is engraved. Many have postulated that “the bullet gets damaged as it enters the rifling” but I could not understand why or how that is possible given that my rifles are very carfully designed and built to be perfectly concentric with chambers and throats that are perfectly aligned in every way, and my ammunition is built to the same exacting standards! I’m willing to admit that my bullets get damaged, but I take issue with the assertion that they are damaged in an way that is not perfectly concentric, and for the “damaged bullet” assertion to be true, they would have to be damaged on only one side, or in a misaligned fashion. That idea may hold up on your Wal-Mart Remington, but not on an MBT custom rifle! It’s impossible. Especially when you figure the fact that both the Wal-Mart Remington and the MBT flame out at exactly the same RPM? It just doesn’t hold water.
Add to that, the fact that I have recovered many bullets from the berm that were shot over the RPMTH and I saw no damage whatsoever (reading through the berm damage obviously). Not a single clue. Not a single hint of bullet imbalance based on visual inspection.
Of course, all of the bullets I observed were almost completely destroyed by the impact, so I needed a way to engrave the bullet like it would be as it was fired from the rifle with a full charge of powder.
After looking at a few pressure trace graphs, I thought that maybe I could use a small charge of fast burning powder to stuff the bullet into the rifling in a very similar fashion as it would be when a column of slow powder was ignited behind it, but without the subsequent buildup of pressure that accelerates it into warp speed and destroys it on the backstop. All I realty need is the first inch of bullet travel!
So I loaded one of my rifles with a very small charge of Bullseye powder and used it to shoot bullets into a bucket filled with wet sand.
I dug out the bullets as they were shot and scrubbed them gently with Dawn dish soap and a soft bristle brush in the sink, patted them dry, then observed them under magnification with a Bosch and Lomb microscope.
At first, I didn’t see anything that looked out of place. I saw a small amount of skid as the bullet engraved the rifling, but it was very concentric and even. Nothing was really standing out at me that would suggest an imbalanced bullet. I shot every 30 caliber mold design in the shop and carefully observed each of them.
The big light bulb moment came when I was observing a Lovern style bullet (311466) and I noticed that the rifling marks were not straight. It seemed that the bullet had become twisted when it gently impacted the wet sand in the bucket. I did the test again, and fired a few of that same bullet and looked at each one under magnification. They all exhibited the same slightly twisted look.
Suddenly, I realized what I was looking at! The bullet is a soft but strong material! What was happening was that the nose of the bullet engraved first and was commanded to spin by the rifling (as evidenced by the slight skid marks on the nose) while the base was still stationary. The base of the bullet caught up a little slower than the nose of the bullet, but when the bullet exited the muzzle, the bullet was strong enough to try to right itself in flight. Effectively doing a “dishrag twist” as it flies. There’s no way that centrifugal force is going ignore that vibration. At a certain point (I believe a VERY SPECIFIC POINT) the centrifugal force produced by the RPM is going to use that to overcome the stabilizing fact of the bullet’s spinning, and thus you have the RPMTH. I think I just popped the big red balloon the RPMTH was hiding behind.
Now, armed with this knowledge, I designed the 30XCB bullet. My objective was to make the rifling engrave the bullet right in the middle of the projectile, so that neither the nose nor the base had much chance to get engraved in a strange way (in fact, the nose has no opportunity at all, and nose slump is the only thing to worry about). The bullet was designed to be controlled by the rifling at all costs, to obtain as much BC as possible. It was designed to be balanced and to resist getting twisted head-on by being cast of strong alloys and being designed to survive every stage of the firing process. I believe the instant success of this bullet in all kinds of rifles across the board speaks to the fact that I was definitely onto something, and this bullet ended up being the golden ticket for the HV slow twist method.
Now, let’s apply this knowledge to the other methods of shooting HV cast bullets and see how it plays out.
HV with standard twist:
The hallmark 30 caliber bullet of the HV with standard twist crowd is the venerable Mi-Heck 30SIL. This bullet is everything the 30XCB is not. It has a progressive nose that is hourglass shaped and touches the crest of the ogive and the flare of the skirt just in front of a positively cavernous lube groove which renders a suspiciously thin core that connects the front of the bullet to the little base that holds the gas check. Given what I learned from the sandbox test (which this bullet was part of) this has to be the worst possible design in the history of HV shooting. Or is it? The fact is, wherever I would opt to make the bullet strong, the designer of the 30SIL designed in a weakness. Add to this the fact that the people who use this bullet to achieve unbelievably high velocities also insist on alloys that are very similar to those used in jacketed bullets (some even use range scrap exclusively) which have (amongst other properties) the ability to be twisted without springing back. In other words, the bullet engraves the rifling in the same twisted fashion and takes a set in that condition while still in the barrel which allows it to emerge as a stable projectile capable of much greater RPM, and theoretically, the harder you push it, the better it will like it, to a certain point.
Very few have been able to feel out the specifics of this method with even one rifle but it has been done numerous times.
Let’s consider paper patched bullets:
It is my belief that the paper jacket works just like a copper jacket. It protects the core of the bullet (our cast bullet in this case) from getting twisted by the rotational inertial as the bullet is being spun up and engraved. The patch itself allows the bullet to slip beneath it. This is one big reason you NEVER get good results if you glue the patch to the bullet. I’ve got news for you, once the bullet leaves the barrel, it doesn’t matter whether the patch stays attached, or comes of as confetti or paper dust. The main function of the paper patch is to help the bullet survive the first inch of acceleration, and get it out of the barrel in an “at rest” fashion, which it does quite well. The main problem with paper patching is getting a paper that protects the bullet well while keeping it perfectly aligned in the barrel, while not jacking with the flight as it is jettisoned at the muzzle. Basically, the paper does a great job of protecting the bullet, but it does an even better job of jacking up umpteen other things if you don’t do them right! Gotta TAME that rascal!
Copper enhanced alloys:
This is simply strengthening the bullet so much that it can resist getting twisted. That’s all I’m going to say about this method because I have not personally experimented with it enough but it can’t be left out of the discussion.
Now, I’ll tell you something else concerning jacketed bullets:
THEY DEAL WITH THE SAME ISSUE and they deal with it better than anything else.
I have cut open quite a few jacketed target bullets and XRF tested them to see what alloy is used in their cores. By and large, the alloy is pure, dead soft lead. That soft lead core, combined with a hard jacket made of perfect bearing material does something that our bullets cannot ever do. The cores twist and settle perfectly in that first inch of rifling and actually work like a shock absorber or a mercury recoil tube. That bullet leaves the muzzle as dead as a hammer with a hard jacket that will keep it together during enormous RPM and centrifugal force, and keep it safe all the way to the target up to 2 miles away. You can’t beat that with a wet squirrel.
This is what I have gleaned from the XCB project, and where my mind has been while I have been working towards HV cast bullets. I’m hoping people do not get the impression that there is a single way to do this, or that one way is smart, while others are dumb etc etc etc. Shooting HV cast bullets is a hard thing to do, and there are several ways to do it. One thing I think I can say with certainty is that it’s expensive. You have to pay the piper with time or money and there is no way around it.
Conclusions
So HV cast bullets is not economical which is the reason many people get into this sport. It’s still cool as all get out, and gets you lots of looks at the range from people who can’t shoot an AR-15 as well as you do your 30-06. LOL!
For me, it was about seeing what’s out there, how it works, and why it works. I’m satisfied with what I have learned so far, and what has been achieved. I hope everyone here has benefited greatly from the efforts of everyone who contributed to the HV cast bullet pursuits described (and at times fought over) by all involved. I can say it’s been the most exciting and grandest project I’ve ever attempted, and I appreciate having a place to tell people about it instead of the knowledge being mine alone and lost to anyone who might wish to do the same thing.
Thanks!