Questions for HBN,Boron Nitride) users

[maxpower]

Now that HBN has been around and tried for a while, I,m checking on any new thoughts and developements on its use. How many shots does it take for the barrel to settle down after cleaning when using HBN? Does it build up in the throat at all? When using BHN coated bullets, how many rounds do you fire before powder fouling becomes an issue?
How do you clean? Is it a light patch out every 50-60 shots, then a full brush out every 2-300 or so?
I had a bad experience lately with a build up in the 1st 5-6' of the barrel, which I put down to powder fouling,Used VV N560), could it have been a build up of HBN?

 

[watercam]

Been using Boron coated bullets from D. Tubb,DTACs). Frankly I don't see a necessity to clean more than every 200-300 rounds for High Power games,Tubb says he goes 450 or so). At that point I clean down to bare metal with Sweets and every 500-600 rds. polish with 50-60 passes each of both JB products. 1100 rounds into a True Flight barrel in 6XC with no accuracy fall-off as yet. Can't see any sign of build-up with my bore scope.

 

[spclark]

Been using hBN in my OTC upper,6HAGAR) and one LR gun,30' Bartlein 6XC) & haven't seen evidence of build-up so far. The upper I clean every other 80-round match, the LR gun after perhaps 100 rounds.

VV propellants are generally pretty clean; what cartridge are you shooting it in?

 

[maxpower]

I have been using it in a 6x47. It shot great for a while, then realy fell off the wall.

 

[Will]

maxpower, care to explain 'Fell off the wall'? What happened, what is your coating method, how many rounds fired, what size hBN ?

I have used moly for over a 15 years and only the last year started using hBN and I have found it to be better than moly. The only issue is being able to see how well the projectiles were coated and I have that beat now.

Do tell what went wrong & how.

 

[Idaho_Elk_Huntr]

Would you guys be willing to share your coating process?

 

[spclark]

Maxpower I'd be interested to hear the details too....

IdahoEH - I tumble new bullets in fresh corn media for about 30 minutes, then put 50 into well cleaned peanut butter plastic jars filled an inch with NECO steel ball bearings. Add 1 grain of 50 micron hBN powder, screw on the lid and secure with gaffer tape.

I've only messed with 6mm bullets so far; this works for everything from 85 gn Sierra BTHP's up to DTAC115's I bought uncoated.

Two of those jars go into an RCBS rotary tumbler for two hours' spin. Remove the jars,tricky so I made a 'special tool' out of a length of 12 gauge electrical wire that loops over the caps) remove the tape, uncscrew the lid & pour the contents into a NECO sieve to separate.

I can't tell the difference on paper between factory-coated Tubb DTAC115's & those I've coated. Berger 105VLD's are quite capable of cleaning 600 prone in 6HAGAR if I do my part.

Once I've loaded each round in my press I use a 3' flannel patch to wipe the excess hBN off the bullets before putting the round into a cartridge case.

 

[Will]

I take 100 bullets and spread them on a towel then spray with either acetone or denatured alcohol. Fold towel and shake, dump bullets in 'OSCAL' pill bottles add about 1/8 teaspoon hBN, close tightly and place in bowl of my vibratory tumbler,usually 3 of those pill bottles). Lock down lid and turn on, come back in an hour or 2 and turn it off, dump bullets in another clean towel, fold & shake .

I shoot nothing but 308 in centerfire rifle. I had thought to send 1K to David Tubb's company and have them do it just so I could see how a commercial finish would look & feel. So far I haven't convinced myself I really need to do that. FWIW. I originally tried coating the projectiles just by dumping in the bowl like I did with moly. Didn't work as planned ... some got coated some didn't. Either had too many bullets,not enough hBN) or ???
HTH

 

[Idaho_Elk_Huntr]

I have a thumlers Model T 3 lb tumbler that I am trying. I was with dish soap and water then dry. I use copper BB's and probably to much hBN. Let it go for 3 hours. Bullets dont seem to be a slick as some people claim. No problem picking them up with my fingers. I use the 70nm stuff.

Pics at bottom are the tumbler, Accubonds just out of tumbler and E-Tips after they came out and was shaken out in towel.

 

[nmiller]

I'm glad someone else is wondering what I have been. I have been fooling with HBn for a few months and I like it over moly if nothing else just for the lack of mess and humidity insensitivity. I have also questioned what my finished bullets should look like and I have been using mine in the powdery state that Idaho Elk posted on top. I am kind of nervous that if I keep leaving this much on it could start loading the barrel and cause more problems than it is solving. I haven't been wiping them because I also don't think they're really that slick when I pull them out even after wiping. Without a color left on the coating I feel like it's hard to tell the quality of my coating and it's affinity toward sticking to my bullets. I am coating about 40 6mm 105s in each large pill bottle and few hundred 1/8' ball bearings, tumbling for about 1-2 hrs. I prep them by sloshing in MEK and drying completely with compressed air. I have also washed with hot soapy water rinsing hot and drying with comp. air or 150 deg. in the toaster oven for 10 min. Still not much difference in results. I have been using about 1/8 tsp. HBn depending on how the bearings look, maybe less. Any input is great. I just want to get a little better consistency and make sure that I'm not making a mistake. Thanks

 

[maxpower]

The way I have been coating the bullets is with one of the Neco kits with the ceramic tumbling media. I have been cleaning them by putting them into a jar of white spirits,lighter fluid), swishing around, then tipping the lighter fluid out, which dries them real quick. Then I tumble them in the ceramic media for 2-3 hrs. They come out looking frosty as in the pictures, then I wipe them down and the bullets do feel slippery but not a slippery as some claim, as other said.
As for the accuraccy, at 600y, I got a good group, only 2,out of 10) out of the X ring, the others just out with wind. Then at 700, I lost 3 or 4 up and down, just into the next ring. At 800, the verticle was more extreme, up and down 2-3 rings. I was wondering if it was build up in the throat, either powder or HBN which caused the tightness in the throat. I had heard Vihta Vouri was a clean powder, especialy when pushed hard, so I was wondering about the HBN???

 

[1shot]

All,
So far the bulk of this thread has been about the application of Hbn. Can anyone give all of us a definitive answer what it does for your accuracy, velocity, and ammunition consistency. i.e. lowering your ES and SD when chronographing your loads as compared to bare bullets with all else being equal?
Thanks,
Lloyd

 

[Will]

1shot, I'd really like to give all those wonderful,but useless to me) ED & SDs but I haven't used a chrono in a few years. I can however, tell you that going from moly to hBN has caused me to drop elevation from 15.5 minutes @ 600 yds to 13.25 this last session. That is using 170 lapua FMJrBT,D46)hBN, Hornady match case, either IMR4895 or N150 as powder. This pic is from today @ 500 yds.

2nd pic is 600 yds, with a 1st round at 2,edge of target)N150 and the very bottom group is also N150 holding at bottom of target.
Group around 3' center is 4895 and the hits at 3:30-4 are also sighters.

HTH