It seems to me that most match bullets are BT bullets. However, I've noticed that some Lapua bullets are rebated BT. There was a resent thread about making your own match bullets and the company that makes the dies for the bullets seems to only offer rebated BT dies for their match bullets. Are they that much better? And if so, then why don't more companies use this profile for their bullets?
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Rebated Boat Tail Bullets
- Thread starter johngfoster
- Start date
Re: Rebated Boat Tail Bullets
Lapua is getting away from the Rebated BT as witnessed by the Scenar. Almost impossible to find the 170 and yes you will find 185s but the seller wants to part with them at Scenar pricing ! They work great in some barrels and did well in International match shooting in Europe. Not all 7.62 rifles had .308 bores and if you had one that ran larger ... well the swell at the base of the rebate helped seal the bore.
I found them to work quite well (170 gr) all the way out to 1K in my GAP w/ Schneider 5P barrel. I was even using the Lapua website load for 170 grain & N150 .
HTH
Lapua is getting away from the Rebated BT as witnessed by the Scenar. Almost impossible to find the 170 and yes you will find 185s but the seller wants to part with them at Scenar pricing ! They work great in some barrels and did well in International match shooting in Europe. Not all 7.62 rifles had .308 bores and if you had one that ran larger ... well the swell at the base of the rebate helped seal the bore.
I found them to work quite well (170 gr) all the way out to 1K in my GAP w/ Schneider 5P barrel. I was even using the Lapua website load for 170 grain & N150 .
HTH
Re: Rebated Boat Tail Bullets
The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail.
Tests show it has similar performance to a regular boattail.
If bullets are made in comercial transfer presses that have more complicated die systems then a regular boattail is not that difficult to make.
A rebated boattail is not superior to a regular boattail from a purly aerodynamic view point as far as I can see.
Rebated boattails may have a good reputation because they are mostly hand made bullets. However I suspect that some bullet companies are making rebated boattails on commercial gear just to cash in on the idea that they are better.
I would not choose a bullet just on the fact it had one type of boattail or another . I would go on its overall performance and its suitability for the job.
The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail.
Tests show it has similar performance to a regular boattail.
If bullets are made in comercial transfer presses that have more complicated die systems then a regular boattail is not that difficult to make.
A rebated boattail is not superior to a regular boattail from a purly aerodynamic view point as far as I can see.
Rebated boattails may have a good reputation because they are mostly hand made bullets. However I suspect that some bullet companies are making rebated boattails on commercial gear just to cash in on the idea that they are better.
I would not choose a bullet just on the fact it had one type of boattail or another . I would go on its overall performance and its suitability for the job.
Re: Rebated Boat Tail Bullets
The "advantage" that I read on Corbin's website is that upon exiting the bore, the rebate design allows a quick release of the gas and it is directed more "away from" the bullet which has a smaller effect than a standard boat-tail. While this may be true, the effect of the gas is probably more related to the crown so I'm not so sure the rebated design really has any advantages. I think they're both pretty much the same.
The "advantage" that I read on Corbin's website is that upon exiting the bore, the rebate design allows a quick release of the gas and it is directed more "away from" the bullet which has a smaller effect than a standard boat-tail. While this may be true, the effect of the gas is probably more related to the crown so I'm not so sure the rebated design really has any advantages. I think they're both pretty much the same.
Re: Rebated Boat Tail Bullets
I'm thinking that the rebate results in a longer bearing surface relative to overall projectile length. I'm guessing this could have consequences related to pressure/velocity and possibly also rifling twist requirements.
I'm thinking that the rebate results in a longer bearing surface relative to overall projectile length. I'm guessing this could have consequences related to pressure/velocity and possibly also rifling twist requirements.
Re: Rebated Boat Tail Bullets
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail. </div></div>
This is the only justification that I have ever heard that jives with the classes I took in grad school. It doesn't hurt in the long run because the bullets being produced are generally of exceptional quality anyway, so comparing them to "hi quality" commercial bulk shows a performance increase with the rebated design, commonly attributed to the bullet design and not the quality of the product.
Personally, I'm working on making dies for myself to produce 224's and 243's diameter bullets from 22LR cases since I can't afford to go buy Corbin's commercial solution, and the static stress analysis that I did on the base forming die showed that there was little chance of the edge of the die surviving 100,000 cycles (I figured if I make 100k bullets I'm probably already dead of old age)
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail. </div></div>
This is the only justification that I have ever heard that jives with the classes I took in grad school. It doesn't hurt in the long run because the bullets being produced are generally of exceptional quality anyway, so comparing them to "hi quality" commercial bulk shows a performance increase with the rebated design, commonly attributed to the bullet design and not the quality of the product.
Personally, I'm working on making dies for myself to produce 224's and 243's diameter bullets from 22LR cases since I can't afford to go buy Corbin's commercial solution, and the static stress analysis that I did on the base forming die showed that there was little chance of the edge of the die surviving 100,000 cycles (I figured if I make 100k bullets I'm probably already dead of old age)
Re: Rebated Boat Tail Bullets
Not if your buddies start putting the arm on you to share your output.
Not if your buddies start putting the arm on you to share your output.
Re: Rebated Boat Tail Bullets
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail. </div></div>
This is the only justification that I have ever heard that jives with the classes I took in grad school. It doesn't hurt in the long run because the bullets being produced are generally of exceptional quality anyway, so comparing them to "hi quality" commercial bulk shows a performance increase with the rebated design, commonly attributed to the bullet design and not the quality of the product.
Personally, I'm working on making dies for myself to produce 224's and 243's diameter bullets from 22LR cases since I can't afford to go buy Corbin's commercial solution, and the static stress analysis that I did on the base forming die showed that there was little chance of the edge of the die surviving 100,000 cycles (I figured if I make 100k bullets I'm probably already dead of old age) </div></div>
The rebate came first due to engineering limitations then the explanations of how it worked or what it did . I suspect that some of the explanations are very convienient.
That does not mean that the rebated boat tail does not work. Sure it works to reduce drag compared to a flat base but does it work better than a smooth transition boat tail? A canular in a bullet will increase drag. So I am fairly confident that the sharpe transition edge to the boat tail does have some extra drag involved compared to a smooth transition boat tail. However for hand swagers the rebated is the easiest way to go that I know of .
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail. </div></div>
This is the only justification that I have ever heard that jives with the classes I took in grad school. It doesn't hurt in the long run because the bullets being produced are generally of exceptional quality anyway, so comparing them to "hi quality" commercial bulk shows a performance increase with the rebated design, commonly attributed to the bullet design and not the quality of the product.
Personally, I'm working on making dies for myself to produce 224's and 243's diameter bullets from 22LR cases since I can't afford to go buy Corbin's commercial solution, and the static stress analysis that I did on the base forming die showed that there was little chance of the edge of the die surviving 100,000 cycles (I figured if I make 100k bullets I'm probably already dead of old age) </div></div>
The rebate came first due to engineering limitations then the explanations of how it worked or what it did . I suspect that some of the explanations are very convienient.
That does not mean that the rebated boat tail does not work. Sure it works to reduce drag compared to a flat base but does it work better than a smooth transition boat tail? A canular in a bullet will increase drag. So I am fairly confident that the sharpe transition edge to the boat tail does have some extra drag involved compared to a smooth transition boat tail. However for hand swagers the rebated is the easiest way to go that I know of .
Re: Rebated Boat Tail Bullets
Rebated BT is old school. My reloading manual from the 1970's display target bullets of this type.
Good luck
Jerry
Rebated BT is old school. My reloading manual from the 1970's display target bullets of this type.
Good luck
Jerry
Re: Rebated Boat Tail Bullets
The truth is your talking nonsense! Not only are RBT advantageous, so much so the principle tooling manufacturer for swaging dies only makes BT dies to special request.
D.R. Corbin, President
July 5, 1986
(Refer to Dr. A.B. Bailey, "An Aerodynamic Study of the Lapua Step Boat-tail Rifle Bullet and its
Ballistics", 1981, Endrickvale, Fintry by Glasgow, Scotland, to R.H. Kent, "The Theory of the Motion of a
Bullet About Its Center of Gravity in Dense Media, with Applications to Bullet Design", January 1957,
Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland, USA, and to D.L. Walters, "Crosswind
Weighting Functions for Direct-Fire Projectiles" (Report X-65), August 1975, Atmospheric Sciences
Laboratory, US Army Electronics Command, White Sands Missile Range, New Mexico, USA, for background
and mathematical support of the summary presented here.)
When a flat base bullet flys through the air at any velocity, it displaces an equal volume of air which
then rushes in behind the passing bullet to fill the vaccuum. This happens at any velocity. But at speeds
below Mach I (speed of sound), the drag caused by this turbulence is greater than most of the other forces
slowing down the bullet. When the sound barrier is crossed, the air is compressed faster than it can move
out of the way, and it compacts into a dense wave that is dragged along by the nose of the bullet. Moving
this compressed shock wave adsorbs far more energy than the turbulent base drag. Thus, at super-sonic
speeds, the nose shape has a greater effect than the base shape on the total retardation of the bullet (as a
percentage of total drag).
If the base of the bullet were made more streamlined, then the air would be put back together more
smoothly, with less turbulence, and would fill the space left by the passing bullet more quickly. This would
eliminate much of the base drag. Putting a point on both ends of the bullet accomplishes this, but it generally
makes the bullet too long, so that it takes up too much powder space or causes other physical problems
in a practical size cartridge case or gun. There is no technical reason why a double-ended bullet should not
be used to overcome drag, except for these physical considerations.
The next best idea is to use a truncated conical shape on the base, so that the bullet has some
degree of streamlining to help reduce base turbulence. The conventional boattail does this reasonably well.
By having a base that is made of an angled portion of the shank, the size of the flat base is reduced so that
the turbulence works on a smaller area. A typical, practical size of boattail has from nine to fifteen degrees
(measured from the center-line of the bullet) and is about a caliber long. There is no great difference in the
performance of any specific angle or length within this general range.
The boattail reduces base drag at all velocities, but has the greatest percentage of effect when the
bullet is flying at sub-sonic velocity. Thus, it is more important for slow bullets, or bullets fired at long
ranges, than for bullets which will be moving at super-sonic speed over their entire path to the target.
Ideally, pistol bullets should be boattails. However, due to the length and weight limitations imposed on
most pistol bullets, this superior design is rarely used for handguns. It is often applied to rifle designs where
it will have relatively little effect, but is primarily effective for promotional purposes.
The truth is your talking nonsense! Not only are RBT advantageous, so much so the principle tooling manufacturer for swaging dies only makes BT dies to special request.
D.R. Corbin, President
July 5, 1986
(Refer to Dr. A.B. Bailey, "An Aerodynamic Study of the Lapua Step Boat-tail Rifle Bullet and its
Ballistics", 1981, Endrickvale, Fintry by Glasgow, Scotland, to R.H. Kent, "The Theory of the Motion of a
Bullet About Its Center of Gravity in Dense Media, with Applications to Bullet Design", January 1957,
Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland, USA, and to D.L. Walters, "Crosswind
Weighting Functions for Direct-Fire Projectiles" (Report X-65), August 1975, Atmospheric Sciences
Laboratory, US Army Electronics Command, White Sands Missile Range, New Mexico, USA, for background
and mathematical support of the summary presented here.)
When a flat base bullet flys through the air at any velocity, it displaces an equal volume of air which
then rushes in behind the passing bullet to fill the vaccuum. This happens at any velocity. But at speeds
below Mach I (speed of sound), the drag caused by this turbulence is greater than most of the other forces
slowing down the bullet. When the sound barrier is crossed, the air is compressed faster than it can move
out of the way, and it compacts into a dense wave that is dragged along by the nose of the bullet. Moving
this compressed shock wave adsorbs far more energy than the turbulent base drag. Thus, at super-sonic
speeds, the nose shape has a greater effect than the base shape on the total retardation of the bullet (as a
percentage of total drag).
If the base of the bullet were made more streamlined, then the air would be put back together more
smoothly, with less turbulence, and would fill the space left by the passing bullet more quickly. This would
eliminate much of the base drag. Putting a point on both ends of the bullet accomplishes this, but it generally
makes the bullet too long, so that it takes up too much powder space or causes other physical problems
in a practical size cartridge case or gun. There is no technical reason why a double-ended bullet should not
be used to overcome drag, except for these physical considerations.
The next best idea is to use a truncated conical shape on the base, so that the bullet has some
degree of streamlining to help reduce base turbulence. The conventional boattail does this reasonably well.
By having a base that is made of an angled portion of the shank, the size of the flat base is reduced so that
the turbulence works on a smaller area. A typical, practical size of boattail has from nine to fifteen degrees
(measured from the center-line of the bullet) and is about a caliber long. There is no great difference in the
performance of any specific angle or length within this general range.
The boattail reduces base drag at all velocities, but has the greatest percentage of effect when the
bullet is flying at sub-sonic velocity. Thus, it is more important for slow bullets, or bullets fired at long
ranges, than for bullets which will be moving at super-sonic speed over their entire path to the target.
Ideally, pistol bullets should be boattails. However, due to the length and weight limitations imposed on
most pistol bullets, this superior design is rarely used for handguns. It is often applied to rifle designs where
it will have relatively little effect, but is primarily effective for promotional purposes.
Re: Rebated Boat Tail Bullets
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Emouse</div><div class="ubbcode-body">The truth is your talking nonsense! Not only are RBT advantageous, so much so the principle tooling manufacturer for swaging dies only makes BT dies to special request.
D.R. Corbin, President
July 5, 1986
(Refer to Dr. A.B. Bailey, "An Aerodynamic Study of the Lapua Step Boat-tail Rifle Bullet and its
Ballistics", 1981, Endrickvale, Fintry by Glasgow, Scotland, to R.H. Kent, "The Theory of the Motion of a
Bullet About Its Center of Gravity in Dense Media, with Applications to Bullet Design", January 1957,
Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland, USA, and to D.L. Walters, "Crosswind
Weighting Functions for Direct-Fire Projectiles" (Report X-65), August 1975, Atmospheric Sciences
Laboratory, US Army Electronics Command, White Sands Missile Range, New Mexico, USA, for background
and mathematical support of the summary presented here.)
When a flat base bullet flys through the air at any velocity, it displaces an equal volume of air which
then rushes in behind the passing bullet to fill the vaccuum. This happens at any velocity. But at speeds
below Mach I (speed of sound), the drag caused by this turbulence is greater than most of the other forces
slowing down the bullet. When the sound barrier is crossed, the air is compressed faster than it can move
out of the way, and it compacts into a dense wave that is dragged along by the nose of the bullet. Moving
this compressed shock wave adsorbs far more energy than the turbulent base drag. Thus, at super-sonic
speeds, the nose shape has a greater effect than the base shape on the total retardation of the bullet (as a
percentage of total drag).
If the base of the bullet were made more streamlined, then the air would be put back together more
smoothly, with less turbulence, and would fill the space left by the passing bullet more quickly. This would
eliminate much of the base drag. Putting a point on both ends of the bullet accomplishes this, but it generally
makes the bullet too long, so that it takes up too much powder space or causes other physical problems
in a practical size cartridge case or gun. There is no technical reason why a double-ended bullet should not
be used to overcome drag, except for these physical considerations.
The next best idea is to use a truncated conical shape on the base, so that the bullet has some
degree of streamlining to help reduce base turbulence. The conventional boattail does this reasonably well.
By having a base that is made of an angled portion of the shank, the size of the flat base is reduced so that
the turbulence works on a smaller area. A typical, practical size of boattail has from nine to fifteen degrees
(measured from the center-line of the bullet) and is about a caliber long. There is no great difference in the
performance of any specific angle or length within this general range.
The boattail reduces base drag at all velocities, but has the greatest percentage of effect when the
bullet is flying at sub-sonic velocity. Thus, it is more important for slow bullets, or bullets fired at long
ranges, than for bullets which will be moving at super-sonic speed over their entire path to the target.
Ideally, pistol bullets should be boattails. However, due to the length and weight limitations imposed on
most pistol bullets, this superior design is rarely used for handguns. It is often applied to rifle designs where
it will have relatively little effect, but is primarily effective for promotional purposes. </div></div>
I think you have got your posts mixed up because I never said a rebated boat tail does not work. So get your facts straight first.
Also you know nothing about making bullets or bullet swaging dies of which I make both.
My posts were about how a reabated botails came about ! Why we have them ! Not wether they work or not.
So you are talking nonsense because you missed the point of my posts.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Emouse</div><div class="ubbcode-body">The truth is your talking nonsense! Not only are RBT advantageous, so much so the principle tooling manufacturer for swaging dies only makes BT dies to special request.
D.R. Corbin, President
July 5, 1986
(Refer to Dr. A.B. Bailey, "An Aerodynamic Study of the Lapua Step Boat-tail Rifle Bullet and its
Ballistics", 1981, Endrickvale, Fintry by Glasgow, Scotland, to R.H. Kent, "The Theory of the Motion of a
Bullet About Its Center of Gravity in Dense Media, with Applications to Bullet Design", January 1957,
Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland, USA, and to D.L. Walters, "Crosswind
Weighting Functions for Direct-Fire Projectiles" (Report X-65), August 1975, Atmospheric Sciences
Laboratory, US Army Electronics Command, White Sands Missile Range, New Mexico, USA, for background
and mathematical support of the summary presented here.)
When a flat base bullet flys through the air at any velocity, it displaces an equal volume of air which
then rushes in behind the passing bullet to fill the vaccuum. This happens at any velocity. But at speeds
below Mach I (speed of sound), the drag caused by this turbulence is greater than most of the other forces
slowing down the bullet. When the sound barrier is crossed, the air is compressed faster than it can move
out of the way, and it compacts into a dense wave that is dragged along by the nose of the bullet. Moving
this compressed shock wave adsorbs far more energy than the turbulent base drag. Thus, at super-sonic
speeds, the nose shape has a greater effect than the base shape on the total retardation of the bullet (as a
percentage of total drag).
If the base of the bullet were made more streamlined, then the air would be put back together more
smoothly, with less turbulence, and would fill the space left by the passing bullet more quickly. This would
eliminate much of the base drag. Putting a point on both ends of the bullet accomplishes this, but it generally
makes the bullet too long, so that it takes up too much powder space or causes other physical problems
in a practical size cartridge case or gun. There is no technical reason why a double-ended bullet should not
be used to overcome drag, except for these physical considerations.
The next best idea is to use a truncated conical shape on the base, so that the bullet has some
degree of streamlining to help reduce base turbulence. The conventional boattail does this reasonably well.
By having a base that is made of an angled portion of the shank, the size of the flat base is reduced so that
the turbulence works on a smaller area. A typical, practical size of boattail has from nine to fifteen degrees
(measured from the center-line of the bullet) and is about a caliber long. There is no great difference in the
performance of any specific angle or length within this general range.
The boattail reduces base drag at all velocities, but has the greatest percentage of effect when the
bullet is flying at sub-sonic velocity. Thus, it is more important for slow bullets, or bullets fired at long
ranges, than for bullets which will be moving at super-sonic speed over their entire path to the target.
Ideally, pistol bullets should be boattails. However, due to the length and weight limitations imposed on
most pistol bullets, this superior design is rarely used for handguns. It is often applied to rifle designs where
it will have relatively little effect, but is primarily effective for promotional purposes. </div></div>
I think you have got your posts mixed up because I never said a rebated boat tail does not work. So get your facts straight first.
Also you know nothing about making bullets or bullet swaging dies of which I make both.
My posts were about how a reabated botails came about ! Why we have them ! Not wether they work or not.
So you are talking nonsense because you missed the point of my posts.
Re: Rebated Boat Tail Bullets
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail.
Tests show it has similar performance to a regular boattail.
If bullets are made in comercial transfer presses that have more complicated die systems then a regular boattail is not that difficult to make.
A rebated boattail is not superior to a regular boattail from a purly aerodynamic view point as far as I can see.
Rebated boattails may have a good reputation because they are mostly hand made bullets. However I suspect that some bullet companies are making rebated boattails on commercial gear just to cash in on the idea that they are better.
I would not choose a bullet just on the fact it had one type of boattail or another . I would go on its overall performance and its suitability for the job. </div></div>
Really? Well look again at what you wrote! You may make bullets but I will wager that Corbin have a deal more experience and expertise in making bullets than you.
"The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies"
That is what YOU wrote. Its nonsense. We have RBT's because they are better not just because they are easier to make.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail.
Tests show it has similar performance to a regular boattail.
If bullets are made in comercial transfer presses that have more complicated die systems then a regular boattail is not that difficult to make.
A rebated boattail is not superior to a regular boattail from a purly aerodynamic view point as far as I can see.
Rebated boattails may have a good reputation because they are mostly hand made bullets. However I suspect that some bullet companies are making rebated boattails on commercial gear just to cash in on the idea that they are better.
I would not choose a bullet just on the fact it had one type of boattail or another . I would go on its overall performance and its suitability for the job. </div></div>
Really? Well look again at what you wrote! You may make bullets but I will wager that Corbin have a deal more experience and expertise in making bullets than you.
"The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies"
That is what YOU wrote. Its nonsense. We have RBT's because they are better not just because they are easier to make.
Re: Rebated Boat Tail Bullets
Bryan Litz has done some testing with the rebated boat tail and has found that it is neither superior nor inferior to the smooth transition boat tail in terms of increasing BC.
Now if it is easier or cheaper to manufacture, that would be a reason to do it. Easier to manufacture usually means better and is why flat base outperforms boat tail at short range.
I will note that the idea that the boat tail design works better below mach and that it has only market value is utter hogwash. I can't think of a single boat tail design used at sub-sonic speeds. Even for 308 subsonic, people use heavy boat tails out of habit, but round nosed flat-based are preferred.
Bryan Litz has done some testing with the rebated boat tail and has found that it is neither superior nor inferior to the smooth transition boat tail in terms of increasing BC.
Now if it is easier or cheaper to manufacture, that would be a reason to do it. Easier to manufacture usually means better and is why flat base outperforms boat tail at short range.
I will note that the idea that the boat tail design works better below mach and that it has only market value is utter hogwash. I can't think of a single boat tail design used at sub-sonic speeds. Even for 308 subsonic, people use heavy boat tails out of habit, but round nosed flat-based are preferred.
Re: Rebated Boat Tail Bullets
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Emouse</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail.
Tests show it has similar performance to a regular boattail.
If bullets are made in comercial transfer presses that have more complicated die systems then a regular boattail is not that difficult to make.
A rebated boattail is not superior to a regular boattail from a purly aerodynamic view point as far as I can see.
Rebated boattails may have a good reputation because they are mostly hand made bullets. However I suspect that some bullet companies are making rebated boattails on commercial gear just to cash in on the idea that they are better.
I would not choose a bullet just on the fact it had one type of boattail or another . I would go on its overall performance and its suitability for the job. </div></div>
Really? Well look again at what you wrote! You may make bullets but I will wager that Corbin have a deal more experience and expertise in making bullets than you.
"The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies"
That is what YOU wrote. Its nonsense. We have RBT's because they are better not just because they are easier to make.
</div></div>
You know nothing about how rebated boat tails came into existance moron. They were trying to make normal boat tails and could not produce a lasting successful die system because of the weak punch edges. So as they experimented on the rebated design was the outcome. NO BODY EVER SAT DOWN TO DESIGN A REBATED BOAT TAIL ON PAPER BEFORE THE DIES WERE ACTUALLY PRODUCED.
WE don't have them because they are better , we have them because it is the easiest most reliable way to make a boat tail in hand swagingd dies . WHICH IS WHAT CORBINS MAKE . NONE OF THIS MEANS THAT THEY DON"T WORK , THEY DO.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Emouse</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Country</div><div class="ubbcode-body">The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies. The edge of the punch that forms the boattail would be so sharp it would collapse and be no good.
So they leave the edge of the punch thicker and at 90 degrees.
This creates a strong edged punch and leaves a rebated edge between the bullet shank and the start of the boattail.
Tests show it has similar performance to a regular boattail.
If bullets are made in comercial transfer presses that have more complicated die systems then a regular boattail is not that difficult to make.
A rebated boattail is not superior to a regular boattail from a purly aerodynamic view point as far as I can see.
Rebated boattails may have a good reputation because they are mostly hand made bullets. However I suspect that some bullet companies are making rebated boattails on commercial gear just to cash in on the idea that they are better.
I would not choose a bullet just on the fact it had one type of boattail or another . I would go on its overall performance and its suitability for the job. </div></div>
Really? Well look again at what you wrote! You may make bullets but I will wager that Corbin have a deal more experience and expertise in making bullets than you.
"The truth about rebated boattail bullets is:
The only reason we have rebated boattail design is because it is difficult to make a normal smooth transition boattail in hand swaging type dies"
That is what YOU wrote. Its nonsense. We have RBT's because they are better not just because they are easier to make.
</div></div>
You know nothing about how rebated boat tails came into existance moron. They were trying to make normal boat tails and could not produce a lasting successful die system because of the weak punch edges. So as they experimented on the rebated design was the outcome. NO BODY EVER SAT DOWN TO DESIGN A REBATED BOAT TAIL ON PAPER BEFORE THE DIES WERE ACTUALLY PRODUCED.
WE don't have them because they are better , we have them because it is the easiest most reliable way to make a boat tail in hand swagingd dies . WHICH IS WHAT CORBINS MAKE . NONE OF THIS MEANS THAT THEY DON"T WORK , THEY DO.
Re: Rebated Boat Tail Bullets
It's really simple! Use what works best for you. Duh! Premium bullets cost premium prices but don't always provide premium performance. Most of the advice given on the "Hide" is to help you find out where to start your own trials, not where to end.
It's really simple! Use what works best for you. Duh! Premium bullets cost premium prices but don't always provide premium performance. Most of the advice given on the "Hide" is to help you find out where to start your own trials, not where to end.
Re: Rebated Boat Tail Bullets
Lapua's recent brochure states that their rebated boat-tail D-46 bullet dates back to the 1930's, and I am absolutely certain it was spectacular improvement over flat-base bullets of the time, and continues to be a solid, quality match bullet.
I do not think that anyone would choose it over the Lapua Scenar design today if you were actually in contention to win in a major rifle competition of any kind.
Take a walk down the firing line of any serious rifle competition and see what is being used and what is winning. I submit that you will not see any rebated boat-tail bullets in use. There has to be a reason for that.
Paul
Lapua's recent brochure states that their rebated boat-tail D-46 bullet dates back to the 1930's, and I am absolutely certain it was spectacular improvement over flat-base bullets of the time, and continues to be a solid, quality match bullet.
I do not think that anyone would choose it over the Lapua Scenar design today if you were actually in contention to win in a major rifle competition of any kind.
Take a walk down the firing line of any serious rifle competition and see what is being used and what is winning. I submit that you will not see any rebated boat-tail bullets in use. There has to be a reason for that.
Paul
Re: Rebated Boat Tail Bullets
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Steven Dzupin</div><div class="ubbcode-body"> Hornady did make these in .30 caliber,years ago.
Shot no better or worse than regular boatails IMHO.
Regards,
Steve </div></div>
I have an old box of these in 190 weight.
Sure hope they shoot like crap.........
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Steven Dzupin</div><div class="ubbcode-body"> Hornady did make these in .30 caliber,years ago.
Shot no better or worse than regular boatails IMHO.
Regards,
Steve </div></div>
I have an old box of these in 190 weight.
Sure hope they shoot like crap.........
Re: Rebated Boat Tail Bullets
Hi gang...I have been manufacturing 223. 55,58and 69gr rebated boattail bullets from Corbin dies for personal and my business since 2005. the Investment to do them right is close to 1500.00. I set my goal to be equal the Speer 69gr. HPBT match and the Harnady 68gr BTHP Match. My results have exceeded me expatiation. .227 groups at 200m and a .274 in groups at 400 meters. The rifle that I use has tow uppers, One 18in JP barrel and the other upper is a 24in. DPMS bull barrel with vary similar accuracy. The 18 in. barrel looses it after 350 meters with groups around 4inchs at 400 meters, But the 24 in. bull barrel squeezes sub1 inch groups out to 600 meters. The best loads with the 69 Sierra and 68 Harnady were larger, but the rebated boat tail out performs better at 200 meters and beyond. 600m is the max range were I shoot. At 100 meters both barrels and my Colt Delta H-Bar shoot half inch groups but all three guns stabilize beyond 200 meters. From 50 to 200 meters flat base bullets of the same weight perform better made from the same dies and compared with Midway 55gr.Dog Town and 55 gr FMJ bullets and other comparable bullets, Again the same results on the two rifles. I have never shot the HBAR beyond 200 meters since the souped-up Panther is my baby and is tow rifles in one. I tried to include photos but was unsuccessful in downloading them, I'm new to this and this is my first entry.
Hi gang...I have been manufacturing 223. 55,58and 69gr rebated boattail bullets from Corbin dies for personal and my business since 2005. the Investment to do them right is close to 1500.00. I set my goal to be equal the Speer 69gr. HPBT match and the Harnady 68gr BTHP Match. My results have exceeded me expatiation. .227 groups at 200m and a .274 in groups at 400 meters. The rifle that I use has tow uppers, One 18in JP barrel and the other upper is a 24in. DPMS bull barrel with vary similar accuracy. The 18 in. barrel looses it after 350 meters with groups around 4inchs at 400 meters, But the 24 in. bull barrel squeezes sub1 inch groups out to 600 meters. The best loads with the 69 Sierra and 68 Harnady were larger, but the rebated boat tail out performs better at 200 meters and beyond. 600m is the max range were I shoot. At 100 meters both barrels and my Colt Delta H-Bar shoot half inch groups but all three guns stabilize beyond 200 meters. From 50 to 200 meters flat base bullets of the same weight perform better made from the same dies and compared with Midway 55gr.Dog Town and 55 gr FMJ bullets and other comparable bullets, Again the same results on the two rifles. I have never shot the HBAR beyond 200 meters since the souped-up Panther is my baby and is tow rifles in one. I tried to include photos but was unsuccessful in downloading them, I'm new to this and this is my first entry.
Re: Rebated Boat Tail Bullets
NO BODY EVER SAT DOWN TO DESIGN A REBATED BOAT TAIL ON PAPER BEFORE THE DIES WERE ACTUALLY PRODUCED.
Dave Corbin did,...and the fact that RBT's are less effected in the transsonic/subsonic region certainly endears them to the long range shooter.The gas-sealing, rebated boattail base adds another 10 to 15 percent to the
improvement in accuracy, by reducing the muzzle blast laminar flow around the bullet caused by
conventional boattails (which directs powder gas in front of the emerging bullet, causing turbulence directly
in its path). The spoiler effect of the rebated base edge deflects gas in an annular pattern around the muzzle,
rather than letting gas flow smoothly over the boattail and become focused in front of the bullet
14 secant ULD's where designed specifically for US Govt contract and featured a RBT from the drawing board up.
Like several others here that posted I also utilise Corbin produced tooling in production.
NO BODY EVER SAT DOWN TO DESIGN A REBATED BOAT TAIL ON PAPER BEFORE THE DIES WERE ACTUALLY PRODUCED.
Dave Corbin did,...and the fact that RBT's are less effected in the transsonic/subsonic region certainly endears them to the long range shooter.The gas-sealing, rebated boattail base adds another 10 to 15 percent to the
improvement in accuracy, by reducing the muzzle blast laminar flow around the bullet caused by
conventional boattails (which directs powder gas in front of the emerging bullet, causing turbulence directly
in its path). The spoiler effect of the rebated base edge deflects gas in an annular pattern around the muzzle,
rather than letting gas flow smoothly over the boattail and become focused in front of the bullet
14 secant ULD's where designed specifically for US Govt contract and featured a RBT from the drawing board up.
Like several others here that posted I also utilise Corbin produced tooling in production.
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