Calvin45
Well-Known Member
@K.E.C., this one's for you by request but figured I'd make a dedicated post instead of taking over the copper fouling thread, and, if anyone else is interested, it's here for them.
First off, I wish to acknowledge sources of useful information to me. David Tubb is THE MAN when it comes to the development, experimentation, and perfection of Hexagonal boron nitride as a bullet coating, and is more responsible for making the shooting community aware of it than anyone else. A most valuable and informative source.
Jeff "Broz" at Long Range Only had a very very informative video on YouTube along with commentary on the LRO website. Here's the link
Finally, this website Long Range Shooters of Utah had an excellent article that was of much help as I started my own HBN experimental journey. Link here:
www.longrangeshootersofutah.com
So what's so great about hbn? The claims are that it greatly reduces barrel throat erosion and fouling, has the potential to lower es and sd numbers, allows for higher maximum velocity, is both more temperature stable and chemically stable than ANY competing bullet coating, cannot be rubbed off if applied correctly as it actually impregnates and/or plates the metal, it doesn't just sit on the surface, reduces sensitivity to seating depth, reduces the problematic rapid spike in initial engraving pressure for especially hard bullets, bullets with long bearing surfaces, and bullets made of pure copper which is gummier and pressures up more than gilding metal, and it greatly mitigates the difference between point of impact between cold bore shots and following shots, as well as the need to foul the bore before trusting observed point of impact.
There are limits to the claims. No one said it would file your taxes for you, fix your chronic back pain, or make you a better shot
Having worked with it for years now, I am a believer. Big time. I can personally vouch for it experientially, it lives up to the hype. It does in fact realize all of the properties I cited above. It is non toxic. It is so non toxic that it is commonly used in cosmetics, which is actually what the HBN I purchased years ago was being sold for. The only caveat there is that it is a respiratory irritant by virtue of being a microscopic ceramic powder - it's not wise to handle it roughly, make a dust cloud, and breathe the stuff in, much like drywall dust, diatomaceous earth, flour, or volcanic ash. These things ain't poisonous but don't breathe in dust! Enough said!
The melting point/sublimation point/point at which this stuff become chemically reactive AT ALL is much, much higher than the melting point of the steel in your rifle barrel. Molybdenum disulphide burns well below 1000 Fahrenheit. Something to consider, along with "the moly mess". Moreover both moly and WS2 (tungsten disulphide) are hydrophilic compounds, they attract and bind to water, and result in sulphuric acid being present in your bore, albeit in minute quantity but still…I don't want ANY sulfur containing compounds in the bore of MY rifles, nor anything that attracts moisture and precipitates it from the air. HBN is hydrophobic, chemically inert, and for our purposes has no meaningful temperature ceiling as hitting that temperature would require melting down your rifle with an acetylene torch. It is a ceramic by definition, and ceramic impregnated metals, called cer-Mets in some fields, see use in high pressure high temperature industrial bearings and gears as well as being experimented with in cylinder and piston walls of Indy car engines to increase longevity and reduce friction. The inside of a rifle during firing is indeed a very high temperature high pressure environment. No other commonly used bullet coatings would even stand a chance in those settings.
I have on multiple occasions seen higher velocities before hitting pressure signs with HBN treated bullets compared to naked. NOTE: at equal powder charges the HBN treated bullet will actually be slower as it doesn't generate the same pressure BUT in my experience it allows you to use a higher total charge weight and hit higher total velocity in the end. This is likely to do with INITIAL ENGRAVING PRESSURE…and HBN coated bullets can be thought as having that first and most violent pressure spike, that occurs when the bullet meets the lands of the rifling, dampened out. This is I suspect the reason that they are also, in my real experience, less sensitive to seating depth and exhibit tighter es numbers and less POI shift after the cold bore shot than their naked brethren. It evens things out.
i do beleive it has slowed throat erosion in my .257 weatherby and .300 win mag which I've pushed hard with some very fast "throat melter" loads.
I know for a fact it makes cleaning barrels easier and required less frequently as evidenced by how many shots before accuracy starts to degrade.
I know for a fact that notoriously finicky and erratic pressuring bullets benefit greatly: the original ungrooved Barnes X bullet is a perfect example. It is hard and unyielding, has a long bearing surface, and is made of pure copper, not gilding metal. HBN treatment made them a whole new animal for me, what the XLC from days gone by wished it could have been. Able to reach the same velocities as equal weight naked cup and cores or Barnes tsx bullets with hbn, and not finicky at all regarding seating depth and whether or not the rifle "likes them" which was certainly not the case prior to treatment.
Pay attention the particle size. Mine is .5 UM (dont know to put in the greek character which is the u with the thing sticking down, indicating "micro" here). Many use .7UM, including Tubb I think. If it's over 1.0 you're leaving lubricant territory and getting into abrasive territory, which is NOT GOOD! Moreover at higher particle sizes it will not penetrate the metal's microscopically porous surface so much as just sit on top of it which is not what we want. I purchased this HBN on eBay for less than 20 dollars Canadian shipped though that was over 5 years ago now.
Now before we get to treating bullets, it is advisable to treat the clean bore of your rifle first. Again, clean is the operative word. Once carbon and copper has been removed, I've found best results to run a patch soaked in either acetone or alcohol, let that evaporate dry, and then make a thoroughly mixed suspension just a little HBN powder in again either alcohol or acetone, soak a patch in that suspension, and run it down the bore. That's it that's all. Not sopping wet preferably as that could facilitate pooling and uneven application. As it dries just keep the barrel pointed as straight down as possible. Run a dry patch through after just to be sure there's no unevenness but as the alcohol/acetone dries it leaves behind an oh-so-thin film of hbn in the barrel. Bingo! The first firing of an hbn treated bullet down that barrel impregnates the steel of the bore. Even if you decide all this hbn stuff isn't worth the trouble in the future, that stuff is in there and should add a layer of heat and friction erosion resistance to that barrel as long as it lives.
To treat the bullets I have found two things to be very important: heat and true impact plating. This to say that a vibratory tumbler really is suboptimal, not the best tool for this job. But you do not need to go and buy a rotary tumbler if you don't have one. Nothing about this is expensive. And you likely have access to best tool of all: A CLOTHES DRYER!!!! I'm not joking. It's not just a matter of making do…it's the superior process in my experience, having tried a number of things.
You want to start out with a totally clean container and perfectly clean bullets: oils and grime can inhibit uniformity of application, and application in general. It certainly NEVER hurts to start everything out clean, removing as many variables and possible failure points along the way as possible. I put the bullets in question in a container of hot water with dish soap, shake them around in that for a while then pour into a colander and rinse them off very thoroughly. From there, we cook them. I pour them onto a clean cookie sheet when my wife isn't looking, and bake them in the oven at 225 Fahrenheit for a while. I do not know at what temp plastic tips on bullets get soft and malleable, but I can say it's a lot more than this as I've had zero issues. Bake em for an hour or so, this evaporates any and all water AND starts them out nice and hot, which greatly facilitates the desired outcome in what follows.
I then put them, using a ladle or scoop, not touching them both because they're pretty warm and because I don't want hand oils on my clean bullets, in the clean container (I'm my case an empty H380 1lb canister that I cleaned thoroughly) along with some steel BBs (I've used the same bbs for years, actually cut open number 2 goose shot shells to get them haha) and JUST A PINCH of HBN. The number one mistake EVERY new HBN user makes is using too much powder. A little goes a very long way, too much and it just coats and clumps and doesn't impact plate anything. Do not fill the container all the way. You want these things to tumble and slam into each other to a degree. Duct tape the
out of that container. Then wrap it tightly in a blanket or big towel and duct tape the out of that, think duct tape overkill. You don't want a dryer full of bullets and steel BBs.
Throw that in the dryer, maybe with a few other towels to dampen the "thud", and turn it on for an hour.
Done.
You should not have a bunch of white powder all over everything. The coating if properly done isn't visible as a coating at all, but the bullets WILL look different: less metallic, a more muted lustre, and kind of like a sheen. Here are some pictures of some 200 grain .30 cal smks, 130 grain .270 sciroccos, and 115 grain .257 Berger VLDs, and of the treated bullets beside untreated naked bullets (in the centre for the 270 and 257 Cals) for an easy visual comparison. Note the sheen.
First off, I wish to acknowledge sources of useful information to me. David Tubb is THE MAN when it comes to the development, experimentation, and perfection of Hexagonal boron nitride as a bullet coating, and is more responsible for making the shooting community aware of it than anyone else. A most valuable and informative source.
Jeff "Broz" at Long Range Only had a very very informative video on YouTube along with commentary on the LRO website. Here's the link
Finally, this website Long Range Shooters of Utah had an excellent article that was of much help as I started my own HBN experimental journey. Link here:
Boron Testing - Long Range Shooters Of Utah
Review of: Boron Coating Bullets for Higher Velocity w/o Higher PressureReloading: Geddy NorthrupReviewed by: Bryce BergenRating:5On June 25, 2014Last modified:August 10, 2018Summary:More DetailsLet me first start off by stating that this information is not 100% applicable nor 100% true in ever...
www.longrangeshootersofutah.com
So what's so great about hbn? The claims are that it greatly reduces barrel throat erosion and fouling, has the potential to lower es and sd numbers, allows for higher maximum velocity, is both more temperature stable and chemically stable than ANY competing bullet coating, cannot be rubbed off if applied correctly as it actually impregnates and/or plates the metal, it doesn't just sit on the surface, reduces sensitivity to seating depth, reduces the problematic rapid spike in initial engraving pressure for especially hard bullets, bullets with long bearing surfaces, and bullets made of pure copper which is gummier and pressures up more than gilding metal, and it greatly mitigates the difference between point of impact between cold bore shots and following shots, as well as the need to foul the bore before trusting observed point of impact.
There are limits to the claims. No one said it would file your taxes for you, fix your chronic back pain, or make you a better shot
Having worked with it for years now, I am a believer. Big time. I can personally vouch for it experientially, it lives up to the hype. It does in fact realize all of the properties I cited above. It is non toxic. It is so non toxic that it is commonly used in cosmetics, which is actually what the HBN I purchased years ago was being sold for. The only caveat there is that it is a respiratory irritant by virtue of being a microscopic ceramic powder - it's not wise to handle it roughly, make a dust cloud, and breathe the stuff in, much like drywall dust, diatomaceous earth, flour, or volcanic ash. These things ain't poisonous but don't breathe in dust! Enough said!
The melting point/sublimation point/point at which this stuff become chemically reactive AT ALL is much, much higher than the melting point of the steel in your rifle barrel. Molybdenum disulphide burns well below 1000 Fahrenheit. Something to consider, along with "the moly mess". Moreover both moly and WS2 (tungsten disulphide) are hydrophilic compounds, they attract and bind to water, and result in sulphuric acid being present in your bore, albeit in minute quantity but still…I don't want ANY sulfur containing compounds in the bore of MY rifles, nor anything that attracts moisture and precipitates it from the air. HBN is hydrophobic, chemically inert, and for our purposes has no meaningful temperature ceiling as hitting that temperature would require melting down your rifle with an acetylene torch. It is a ceramic by definition, and ceramic impregnated metals, called cer-Mets in some fields, see use in high pressure high temperature industrial bearings and gears as well as being experimented with in cylinder and piston walls of Indy car engines to increase longevity and reduce friction. The inside of a rifle during firing is indeed a very high temperature high pressure environment. No other commonly used bullet coatings would even stand a chance in those settings.
I have on multiple occasions seen higher velocities before hitting pressure signs with HBN treated bullets compared to naked. NOTE: at equal powder charges the HBN treated bullet will actually be slower as it doesn't generate the same pressure BUT in my experience it allows you to use a higher total charge weight and hit higher total velocity in the end. This is likely to do with INITIAL ENGRAVING PRESSURE…and HBN coated bullets can be thought as having that first and most violent pressure spike, that occurs when the bullet meets the lands of the rifling, dampened out. This is I suspect the reason that they are also, in my real experience, less sensitive to seating depth and exhibit tighter es numbers and less POI shift after the cold bore shot than their naked brethren
. It evens things out. i do beleive it has slowed throat erosion in my .257 weatherby and .300 win mag which I've pushed hard with some very fast "throat melter" loads.
I know for a fact it makes cleaning barrels easier and required less frequently as evidenced by how many shots before accuracy starts to degrade.
I know for a fact that notoriously finicky and erratic pressuring bullets benefit greatly: the original ungrooved Barnes X bullet is a perfect example. It is hard and unyielding, has a long bearing surface, and is made of pure copper, not gilding metal. HBN treatment made them a whole new animal for me, what the XLC from days gone by wished it could have been. Able to reach the same velocities as equal weight naked cup and cores or Barnes tsx bullets with hbn, and not finicky at all regarding seating depth and whether or not the rifle "likes them" which was certainly not the case prior to treatment.
Pay attention the particle size. Mine is .5 UM (dont know to put in the greek character which is the u with the thing sticking down, indicating "micro" here). Many use .7UM, including Tubb I think. If it's over 1.0 you're leaving lubricant territory and getting into abrasive territory, which is NOT GOOD! Moreover at higher particle sizes it will not penetrate the metal's microscopically porous surface so much as just sit on top of it which is not what we want. I purchased this HBN on eBay for less than 20 dollars Canadian shipped though that was over 5 years ago now.
Now before we get to treating bullets, it is advisable to treat the clean bore of your rifle first. Again, clean is the operative word. Once carbon and copper has been removed, I've found best results to run a patch soaked in either acetone or alcohol, let that evaporate dry, and then make a thoroughly mixed suspension just a little HBN powder in again either alcohol or acetone, soak a patch in that suspension, and run it down the bore. That's it that's all. Not sopping wet preferably as that could facilitate pooling and uneven application. As it dries just keep the barrel pointed as straight down as possible. Run a dry patch through after just to be sure there's no unevenness but as the alcohol/acetone dries it leaves behind an oh-so-thin film of hbn in the barrel. Bingo! The first firing of an hbn treated bullet down that barrel impregnates the steel of the bore. Even if you decide all this hbn stuff isn't worth the trouble in the future, that stuff is in there and should add a layer of heat and friction erosion resistance to that barrel as long as it lives.
To treat the bullets I have found two things to be very important: heat and true impact plating. This to say that a vibratory tumbler really is suboptimal, not the best tool for this job. But you do not need to go and buy a rotary tumbler if you don't have one. Nothing about this is expensive. And you likely have access to best tool of all: A CLOTHES DRYER!!!! I'm not joking. It's not just a matter of making do…it's the superior process in my experience, having tried a number of things.
You want to start out with a totally clean container and perfectly clean bullets: oils and grime can inhibit uniformity of application, and application in general. It certainly NEVER hurts to start everything out clean, removing as many variables and possible failure points along the way as possible. I put the bullets in question in a container of hot water with dish soap, shake them around in that for a while then pour into a colander and rinse them off very thoroughly. From there, we cook them. I pour them onto a clean cookie sheet when my wife isn't looking, and bake them in the oven at 225 Fahrenheit for a while. I do not know at what temp plastic tips on bullets get soft and malleable, but I can say it's a lot more than this as I've had zero issues. Bake em for an hour or so, this evaporates any and all water AND starts them out nice and hot, which greatly facilitates the desired outcome in what follows.
I then put them, using a ladle or scoop, not touching them both because they're pretty warm and because I don't want hand oils on my clean bullets, in the clean container (I'm my case an empty H380 1lb canister that I cleaned thoroughly) along with some steel BBs (I've used the same bbs for years, actually cut open number 2 goose shot shells to get them haha) and JUST A PINCH of HBN. The number one mistake EVERY new HBN user makes is using too much powder. A little goes a very long way, too much and it just coats and clumps and doesn't impact plate anything. Do not fill the container all the way. You want these things to tumble and slam into each other to a degree. Duct tape the
out of that container. Then wrap it tightly in a blanket or big towel and duct tape the out of that, think duct tape overkill. You don't want a dryer full of bullets and steel BBs. Throw that in the dryer, maybe with a few other towels to dampen the "thud", and turn it on for an hour.
Done.
You should not have a bunch of white powder all over everything. The coating if properly done isn't visible as a coating at all, but the bullets WILL look different: less metallic, a more muted lustre, and kind of like a sheen. Here are some pictures of some 200 grain .30 cal smks, 130 grain .270 sciroccos, and 115 grain .257 Berger VLDs, and of the treated bullets beside untreated naked bullets (in the centre for the 270 and 257 Cals) for an easy visual comparison. Note the sheen.
