Post by GLSHOOTER on Jun 24, 2014 13:25:46 GMT -8
Table of Contents
About BHW
Why do we use polygonal rifling?
How does your rifling work?
About the 308B chamber
Why do you offer wildcat cartridge chambering?
What kind of steel do you use?
Do you encourage long range shooting?
Suggestions on twist rates
Does barrel length matter?
Barrel fluting – weight and strength
About Black Hole Weaponry
Black Hole Weaponry is located in St. Helens, Oregon. We are a Division of Columbia River Arms LLC. Black Hole Weaponry is locally owned and operated by Carl Caudle, whom has been a gunsmith for over 30 years. BHW specializes in polygonal rifling.
Why do we use polygonal rifling?
The most important reason is the efficiency of this rifling form. Polygonal rifling is known for its durability and accuracy as well as the ease in which is can be cleaned. An increase in velocity has also been reported by those who have used these barrels.
How does your rifling work?
The shape of the lands and grooves are based on a circle, so there are no sharp corners or edges for the bullet to conform into. This means there is a tight seal and thus less bullet deformation. This rifling form is unique in its ability to allow the bullet to be centered and fully supported by the barrel’s bore.
About the 308B chamber
It is a chamber designed to accept the 7.62 Nato cartridge with the throating adjusted to improve accuracy. It works very well and you can use both Nato rounds and the standard 308 Winchester.
Why do you offer wildcat cartridge chambering?
Wildcatting (the use of a non-standard SAAMI approved cartridge) has become a rapidly growing hobby for many of our customers. Our decision to offer wildcat chambering is due to the large number of requests that have come in from our customers to carry this option--they asked and we delivered.
We enjoy being able to offer our wildcat chambering option, however, we must emphasize that knowingly using these types of experimental chambering places all liability solely on the End User.
In an effort to maintain the highest level of enjoyment and satisfaction out of our products, we encourage all our customers to practice safe and responsible means of exercising their hobby.
What kind of steel do you use?
We use an ordinance grade of stainless steel known as 416R. Most of our steel is imported from a German mill that specializes in military grade, high quality, barrel steel.
Carl, Do you encourage long range shooting?
I can boil this subject down to a few simple rules. I developed them when I owned and operated a law enforcement only shooting school.
Caudle’s Rules
1. If you are not going to hit don’t shoot
2. Hit it when you want
3. Hit it where you want
4. Hit it as many times as you want
As long as the normal safety concerns are addressed, then yes, I encourage long range shooting.
Suggestions on twist rates
223/5.56 1x8 all normal bullet weights
6mm 1x10 for bullet weights up to 85 grains and heavier bullets with velocities over 3100fps
1x9 for bullets heavier than 85 grains
264/6.5 1x8 for heavier bullets with a longer length
1x9 for general application
270/6.8 1x11 general application
308 1x11 for all super sonic
1x8.5 for all subsonic
It is important to remember that our rifling tends to be much more forgiving than any other type of rifling. The faster your velocity the less twist rate you need.
Does barrel length matter?
This is a very extensive subject; I will give it a try
Generally speaking, the longer the barrel the best velocity and accuracy is achieved; however, that is not always the case.
The bullet starts with a velocity of zero. It is then pushed to, say, a velocity of 3000 feet per second(fps) within a given distance, represented by the barrels length. This pressure pushing on the bullet also has acceleration to it. If you were to chart this pressure as it burns or expands on a chart it would have a parabolic curve (arc) to it.
With such a broad variety of powders and burn rates available today, the efficiency of any given barrel is more dependent on the ammunition used rather than the barrel’s overall length.
Barrel fluting – weight and strength, does it make a difference?
As you may have already noticed, there is a lot of debate out there on whether or not fluting has a substantial effect on the weight and strength of a barrel. The only thing we can say for certain about our fluting is that it reduces barrel weight by just a few ounces and provides our customers with an aesthetically pleasing design to their barrels.
As for how fluting affects the overall physics of the barrel itself (vibration/resonance, heat dissipation, barrel expansion as the bullet travels, etc…) we choose to leave up to those who wish to expound on the subject.
Have questions for BHW that you would like to see added to our FAQ? Email us!
sales@blackholeweaponry.com
Put attn:BHW Forum in the subject line.
About BHW
Why do we use polygonal rifling?
How does your rifling work?
About the 308B chamber
Why do you offer wildcat cartridge chambering?
What kind of steel do you use?
Do you encourage long range shooting?
Suggestions on twist rates
Does barrel length matter?
Barrel fluting – weight and strength
About Black Hole Weaponry
Black Hole Weaponry is located in St. Helens, Oregon. We are a Division of Columbia River Arms LLC. Black Hole Weaponry is locally owned and operated by Carl Caudle, whom has been a gunsmith for over 30 years. BHW specializes in polygonal rifling.
Why do we use polygonal rifling?
The most important reason is the efficiency of this rifling form. Polygonal rifling is known for its durability and accuracy as well as the ease in which is can be cleaned. An increase in velocity has also been reported by those who have used these barrels.
How does your rifling work?
The shape of the lands and grooves are based on a circle, so there are no sharp corners or edges for the bullet to conform into. This means there is a tight seal and thus less bullet deformation. This rifling form is unique in its ability to allow the bullet to be centered and fully supported by the barrel’s bore.
About the 308B chamber
It is a chamber designed to accept the 7.62 Nato cartridge with the throating adjusted to improve accuracy. It works very well and you can use both Nato rounds and the standard 308 Winchester.
Why do you offer wildcat cartridge chambering?
Wildcatting (the use of a non-standard SAAMI approved cartridge) has become a rapidly growing hobby for many of our customers. Our decision to offer wildcat chambering is due to the large number of requests that have come in from our customers to carry this option--they asked and we delivered.
We enjoy being able to offer our wildcat chambering option, however, we must emphasize that knowingly using these types of experimental chambering places all liability solely on the End User.
In an effort to maintain the highest level of enjoyment and satisfaction out of our products, we encourage all our customers to practice safe and responsible means of exercising their hobby.
What kind of steel do you use?
We use an ordinance grade of stainless steel known as 416R. Most of our steel is imported from a German mill that specializes in military grade, high quality, barrel steel.
Carl, Do you encourage long range shooting?
I can boil this subject down to a few simple rules. I developed them when I owned and operated a law enforcement only shooting school.
Caudle’s Rules
1. If you are not going to hit don’t shoot
2. Hit it when you want
3. Hit it where you want
4. Hit it as many times as you want
As long as the normal safety concerns are addressed, then yes, I encourage long range shooting.
Suggestions on twist rates
223/5.56 1x8 all normal bullet weights
6mm 1x10 for bullet weights up to 85 grains and heavier bullets with velocities over 3100fps
1x9 for bullets heavier than 85 grains
264/6.5 1x8 for heavier bullets with a longer length
1x9 for general application
270/6.8 1x11 general application
308 1x11 for all super sonic
1x8.5 for all subsonic
It is important to remember that our rifling tends to be much more forgiving than any other type of rifling. The faster your velocity the less twist rate you need.
Does barrel length matter?
This is a very extensive subject; I will give it a try
Generally speaking, the longer the barrel the best velocity and accuracy is achieved; however, that is not always the case.
The bullet starts with a velocity of zero. It is then pushed to, say, a velocity of 3000 feet per second(fps) within a given distance, represented by the barrels length. This pressure pushing on the bullet also has acceleration to it. If you were to chart this pressure as it burns or expands on a chart it would have a parabolic curve (arc) to it.
With such a broad variety of powders and burn rates available today, the efficiency of any given barrel is more dependent on the ammunition used rather than the barrel’s overall length.
Barrel fluting – weight and strength, does it make a difference?
As you may have already noticed, there is a lot of debate out there on whether or not fluting has a substantial effect on the weight and strength of a barrel. The only thing we can say for certain about our fluting is that it reduces barrel weight by just a few ounces and provides our customers with an aesthetically pleasing design to their barrels.
As for how fluting affects the overall physics of the barrel itself (vibration/resonance, heat dissipation, barrel expansion as the bullet travels, etc…) we choose to leave up to those who wish to expound on the subject.
Have questions for BHW that you would like to see added to our FAQ? Email us!
sales@blackholeweaponry.com
Put attn:BHW Forum in the subject line.