Hexagonal Boron Nitride

I have fired about 500 coated bullets. I just clean the bullets in acetone, put the hbn and bullets in the bottle and tumble a few hours. No shot or anything else.

I noticed lowered velocities, other than that I cannot say it is worthwhile. Simple enough to do so I'll continue.

Gives nice SDs and ESs.
 

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Add some powder to bring your velocity back to where you were. Unless you want to shoot slower.
 
That, and less barrel fouling, are two of the primary reasons folks HBN coat bullets.


Yes, I cleaned at about 800rounds(half or which were hbn) and found very little copper. I wasn't sure if it was due to the match bbl or the hbn.
 
Question about acetone. Is the reason that some do not want to use it due to the flammability? I am considering using it in large quantities for washing bullets to remove machine oil. Ventilation is not so easy in the winter time, too cold. Does alcohol cut oil as well as acetone but not have the potential for indoor flammable vapor? I'll have to try soaking in alcohol.

Steve
 
Jeff (Broz) has me convinced to try it. I ordered the Tubbs Kit, going to try it with the new 225 ELD in 300 Weatherby and maybe the 147 ELD in Creedmoor..
 
Question about acetone. Is the reason that some do not want to use it due to the flammability? I am considering using it in large quantities for washing bullets to remove machine oil. Ventilation is not so easy in the winter time, too cold. Does alcohol cut oil as well as acetone but not have the potential for indoor flammable vapor? I'll have to try soaking in alcohol.

Steve
You need serious ventalation for both especially in cold weather.
A down draft table venting outside comes to mind.
 
Jeff (Broz) has me convinced to try it. I ordered the Tubbs Kit, going to try it with the new 225 ELD in 300 Weatherby and maybe the 147 ELD in Creedmoor..

I cote almost everything. Even cast lead where I coat in Alox then wipe the excess and tumble in HBN. I like it.

Separate tumblers for copper clad vs lead cast.
 
I cote almost everything. Even cast lead where I coat in Alox then wipe the excess and tumble in HBN. I like it.

Separate tumblers for copper clad vs lead cast.
Good to know Fred thanks.
Do you still use shot as a media or just bullets alone?
 
Good to know Fred thanks.
Do you still use shot as a media or just bullets alone?

The copper clad are tumbled in stainless ball bearings of 3 sizes. These were washed in Alcohol prior to use.

The lead is tumbled in steel shot from some shotgun shells.

You make me think that the lead cast bullets might be better tumbled in lead shot. I'll have to give that a try.

The most fun bullet is for my 45-70 Falling block "buffalo rifle". The bullet is cast from the Lee 500 grain mold https://www.midwayusa.com/product/2...ent-459-diameter-500-grain-pointed-round-nose that I machined down to be a 400 grain. The goal is the Buffalo at the NRA Whitington Center in Raton, NM
 
Question about acetone. Is the reason that some do not want to use it due to the flammability? I am considering using it in large quantities for washing bullets to remove machine oil. Ventilation is not so easy in the winter time, too cold. Does alcohol cut oil as well as acetone but not have the potential for indoor flammable vapor? I'll have to try soaking in alcohol.

Steve

Steve,

I'm a bit lazy and not too finicky about some things. My experience with each caliber and weight of your Hammer Hunters I've shot I haven't "cleaned" any of them.

I have no idea of what you do post removal from the "machine" but when I get them they coat fine (using my empirically developed method).

All of the positive and expected changes in performance has been realized. ES = Ziltch. Copper fouling = Ziltch. First clean cold bore shot in the group. Plus I clean so infrequently that I don't worry about that first cold clean bore shot.

The only anomaly I've experienced is that with my best load in the 375 Allen Mag which is the 395 HH ahead of RL-50 the anticipated velocity drop occurs. The down side is I can't add enough RL-50 to make up the difference.

With the 395 HH starting out at 3125 +/- 2 FPS seems to have enough umpf to get done what needs to be done. :cool:

FYI, when I was cleaning very close dimension tolerance standards which required absolutely no film from the cleaning process (as any film whatever jammed things up) Dial Soap was the only "safe" effective cleaning solution permitted by the manufacturer.
 
Question about acetone. Is the reason that some do not want to use it due to the flammability? I am considering using it in large quantities for washing bullets to remove machine oil. Ventilation is not so easy in the winter time, too cold. Does alcohol cut oil as well as acetone but not have the potential for indoor flammable vapor? I'll have to try soaking in alcohol.

Steve

Acetone is even more volatile than rubbing alcohol.

Dawn Dishwashing Detergent and warm/hot water is about as good at removing oils as anything and is completely safe. Just rinse again with hot water when you are done and if you are concerned about oxidation just give a quick final rinse with some 90% Isopropyl alcohol. You can do the latter outside with just a collander/strainer no matter how cold it is. Even in sub zero weather the alcohol will dry pretty quickly.
 
Seems like most people on this thread have had good experiences with hBN unfortunately I have not. Quite the opposite. My experience was overall terrible and I would strongly recommend against people using hBN. I actually used this thread and several others as a guide on how to properly apply it to my barrel and coated 500 rounds with it. So, it's not like I didn't give it a fair try.

Initially, what I noticed was that bullets were a little harder to insert and my bullet seating die would just ever so slightly dent the tip of my bullets. A perfect little concentric ring around the tip. Didn't happen to all of them but I definitely didn't like it. Not sure if from an accuracy stand point it actually made a difference or not. I shot them anyway.

The next thing I noticed is that they are HARD to pull. Like ridiculously unacceptably hard to pull. In fact, the force required to pull them destroys the bullet. The collet literally can't get a tight enough grip to pull the the bullet unless you cinch it down to the point that it severely deforms/dents the jacket. The reason I think this is 2 fold. 1) hBN is crystalline. As such it gets embedded in the jacket and interposed between the jacket and the brass. Well, there's not much extra space for it so it seems like it creates an absurd amount of neck tension. Combine this with the fact that it librucates the bullet jacket and you get a situation where you're trying to pull a lubed up bullet out of a case that it is literally wedged into. Suffice it to say they don't smoothly come out. Not only are the jackets deformed but you can see linear streaks where the jacket was scratched by the crystalline hBN. When this first happened I was like "Well, if the hype is true, I guess I'll just shoot them out."

So how'd they shoot? Initially, they shot essentially exactly the same as if I was shooting naked bullets except that every now and then I'd get a ridiculous flier. Like it'd be off by 3-4 MOA. I thought maybe I just wasn't being retentive enough with my reloading practices but realistically speaking that's not true. I'm pretty retentive and this gun shoots 1/4 MOA all day. Maybe better. I mean it's a 243 Winchester that literally puts 3 bullets nearly in the same hole. So if you measure the outside diameter at .30 and subtract .243 then it'd be .06. Technically speaking that's better than .1 MOA. It's an accurate rifle. It doesn't really seem to shoot fliers and I feel fortunate to own it. It's a flippin hammer.

What I noticed is that a couple days/ week later when I went and stretched her out a bit was that my relative group size had started to expand. Initially at 350 I was shooting 3/4 MOA and at 475 I was shooting 3/4-1 MOA. Given the location and shooting conditions I was shooting in I chalked it up to the environment and was initially still happy. So I went home and loaded 200 rounds for the next time I went out to shoot. Then came the severe sad face.

A month later (yesterday) I went back and started shooting at 475. I hadn't touched the rifle since and expected it to deliver similar results. No such luck. My groups had opened up to 6 MOA. I shot several more. Still the same. I dropped back to 100 yards. Still the same. I was like ***. I thought maybe I just needed to clean it since I'd put ~ 200 rounds down it but deep down I didn't actually think that was the likely culprit given the fact that it happened so suddenly. Regardless I packed up, went home, and cleaned the **** out of it to give the hBN the benefit of the doubt.

I went back to the range that afternoon and shot five 5 shot groups and they were all anywhere from 4-6 MOA. Definitely wasn't the rifle needing to be cleaned. I packed up, went home, and pulled 20 rounds. Rechecked my powder charge, made sure my primers were all seated completely and reloaded them (the same cases that I literally just took an hBN coated bullet out of) with naked bullets. I then prepped and loaded 6 more cases from scratch as a control.

I went back to the range this morning and first group I shot measured ~1/4 MOA. Cold bore. The next was 3 pretty much in the same hole. Shot a group with the control lot and again the same. The rifle is a hummer. The problem was/is the hBN. What I think happened is that since it's a crystalline material over ~ a month it literally fused with itself in the case neck and since it was wedged in there my neck tension was both ridiculously high and variable depending on how much hBN was interposed and how much had fused together. This caused all sorts of pressure variations and instead of my ES and SD coming down to single digits they went through the roof. Good to know, but a painful and somewhat expensive lesson to learn.

Time to pull a bunch of bullets!
 
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