School me on hBN

[kombayotch]

Next box of DTACs I buy is going to be coated and I'll probably send some bullets to Tubb for coating. Know it's purpose and advantages, etc... But, information is a bit scarce on it...

Three big questions I have:

1) What is the proper way to condition the barrel for/with it?

2) What cleaning supplies are needed and what is the cleaning proceedure?

3) How many rounds before the barrel settles down with each of these?

 

[Dustin Morris]

Re: School me on hBN

#1 Boron nitride doesn;t have to be "conditioned" into your barrel like moly. Shoot the first round and your good.

#2 dont mention cleeaning supplies around here. But if you do clean your barrel, (and I personally do) no extra cleaning supplies are needed, clean like normal, exept less often.

#3 is a doozy, A new barrel like my 243 actualy settles down with fewwer shot after a complete cleaning, like 1 maybe 2.
But an older barrel, like my 6xc with 2k through it takes a little longer to settle down with borob nitride than with naked bullets.

I no longer run naked bullets in my 6mm's. any other questions just PM me

 

[bfoosh006]

Re: School me on hBN

Maybe this will help.. http://www.6mmbr.com/bulletcoating.html and an interesting article... http://www.patentstorm.us/patents/7197986/description.html from here... http://theswissriflesdotcommessageboard.yuku.com/topic/6761

 

[kombayotch]

Re: School me on hBN

And I assume that if I hate the stuff, I can scrub it out with JB right?

 

[427Cobra]

Re: School me on hBN

1 just coat the pills or buy them coated and shootem

2 I clean with BBS and/or Kroil nothing special at all

3 I would say 3-5

4 its not like Moly at all, it has none of the negatives and is a better lube, I doubt you could tell if you ever removed it, but JB is what I would use.

 

[zfk55]

Re: School me on hBN

I'm going to disagree with the barrel prep answer.
When we began, I called the tech rep at the Chicago factory. Actually if you want to insure a properly burnished bore you will need to follow a sequence.
The hexagonal shape of the particles have a couple of unique capabilities. It will ingrain itself into the bore and will not strip away like Moly does.

First, to convince yourself of the difference, take your best accuracy load and chrono and shoot at 100 yards.
Perform the same thing after burnishing and impact coating. For projectile impact coating you can check my son's forum at http://theswissriflesdotcommessageboard.yuku.com/topic/6761 or http://www.ar10t.com/
follow the sequence. He's been highly successful with the process.

Scrub your bore with Barnes or Sweets, follow with 6-10 clean patches until there's no color. Clean as usual with Hoppes, then repeat the process twice more.
Finally, swab the bore with a .30 caliber swab and <span style="font-style: italic">denatured alcohol</span>. Immediately push another 4 or 5 clean patches through the bore.

Assuming you already have impact coated projectiles and loaded them into cartridges, take a new or completely soap and water washed .30 caliber <span style="font-style: italic">dry</span> swab, lightly dust it with hBN and gently push it through the bore from the <span style="font-style: italic">muzzle</span> end, not the breech. Be careful not to damge your crown. Unscrew the swab at the breech end and then remove the rod.

Now fire your first projectile and that's it. From there you can recalculate your load data since you now have a whole new world of opportunites for different load combos open to you.

If you chrono'd that first round and compared it with the pre burnished numbers you'll find an increase in velocity with accompanying lower chamber pressures.

Once burnished, (despite the claim that you can shoot 3 to 5 uncoated projectiles before the next coated one fired) shoot only hBN impact coated projectiles.

I'll be updating both forums for the interested parties, so if this is of interest you can follow progress of the new project. A Wilson AR10.
My son's 22-250 went immediately after burninghing and projectile coating from a nominal 1" group to an easy .34". Now he's working with new load data getting it even tighter.

As for removing it, just use denatured alcohol, scrub with a brass brush, swab and follow with Hoppes.

zfk55

 

[Partagas]

Re: School me on hBN

Where can you get the stuff?

 

[zfk55]

Re: School me on hBN

Here.......
http://sandblastingabrasives.com/contact-us.html?action=success

zfk55

 

[427Cobra]

Re: School me on hBN

I never burnished mine, oh well, and don't think I will on the next barrel.

I got .5 micron from www.lowerfriction.com, 1lb should last a lifetime, everything I read pointed to .5 as the stuff to get, I use one of those Lee scoops from a .223 die set per 100 pills, bb's and peanut butter jars in a RCBS vib tumbler, Scenars 1 hour, everything else 30 minutes.

 

[zfk55]

Re: School me on hBN

The only reason we didn't go with Lower Friction is that its in Canada and the other one is in Denver. Just shipping charges and duty reasons and time in transit. Not a big deal. Negative 5 is negative 5.
Bore burnishing was simply because the factory tech told us to do it. The stuff was designed for fine gear and surface wear reduction, so they treat any metals the same way at the outset.
If yours works, who can dispute it? Its all new science to me.

zfk55

 

[Goin'Hot]

Re: School me on hBN

Tag

 

[kombayotch]

Re: School me on hBN

Thanks guys!

 

[former naval person]

Re: School me on hBN

zfk...went to the US site and have a question. I am using .5 micron...one half micron. They state that -5 micron averages 2 to 3 microns...a great deal coarser. Does that make a difference in the conditioning?

 

[mexicanmatch]

Re: School me on hBN

nice tech articles, enough to get one confused, i guess

 

[Niles Coyote]

Re: School me on hBN

tag

 

[zfk55]

Re: School me on hBN

Ok. After a learning curve, we're there.
To save retyping everything, this is an email I sent to the builder.

-------------------------------------------------

Hello, Stewart. Hope this find you well.
This is a sequence of the errors made in the runout of the Wilson AR10, and I thought it might interest you.

1) Complete barrel maintenance to remove any traces of Moly.
2) 175gr Sierra MK, 43 grains of RE15, Lake City Match cases FLS
3) Primer: Federal 210
4) TTL: 2.015, OAL: 2.860
5) hBN Coated as per on-line instructions.
6) Clean, dry swab with a dustin of hBN passed through the bore from the breech end and the swab unscrewed form the muzzle end before withdrawing the rod.

Day 1:
First group of 5 at 100 yards, one ragged hole, and not much over .675
Second group opened to 1"
Third group opened to 1.25" and pretty much stayed there for consecutive strings.
(A very discouraged Latigo)

Back to the reloading room for a sequence check, and this one is my error.
With our progressive presses ( and all standard progressives) in the reloading room the sequence is TTL, primer pocket swage, flash hole ream, lube, cycle through the Dillon with all dies preset to a full cartridge reload. For the Wilson all case prep and reloading was individually done by hand, however.......... The typical sequence on all progressives is out of sync with reality. This is something I knew and had simply forgotten in the years of (lazy) progressive reloading. You cannot TTL and then FLS. This is an error in the progressive sequence of thought and design. For true maintaning of TTL, the sizing must come first. Simple reloading 101, but the simple is not always considered.
After TTL and upon FLS the case length in each case increased (unnoticed) to a spread of 2.022 to 2.028, thus the first suspected reason for group size increase from .675 to moa.

Back out to the range with newly prep'd, sized (properly this time) and reloaded cases.
Results: little change. I'm going to leave out a number of returns to the reloading room for an additional 4 checks and 5 group reloads. We fooled around with the OAL a few times and then......... a lightbulb went off above my head. Not dead center as most of my ideas are slightly askew, but definitely a flash of reason. The hBN. What if the process was incorrect. Back to the net for some in-depth research and re-reading of the patent information. Were the projectiles simply not coated enough? Now..... go back and read item number 6 above. That process was enough to cause the Wilson to shoot .675 on the first string with a steadily opening group sequence. Back out to the range with a swab, rod and hBN. One simple pass through the bore and the Wilson went immediately back to a group .5 wide and .658 high. Idiot! I had believed a sequence posted by a large user as being logical and correct. It wasn't. The required amount went from 2.5gr per 100 to a nominal 8gr per hundred 175s.
We're back on track, Stewart, and we'll send you target pictures this week. I suspect you're in Italy at the moment, so don't drink the water, enjoy the ladies and stay low.

Pierre

 

[Falar]

Re: School me on hBN

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">I never burnished mine, oh well, and don't think I will on the next barrel.

I got .5 micron from www.lowerfriction.com, 1lb should last a lifetime, everything I read pointed to .5 as the stuff to get, I use one of those Lee scoops from a .223 die set per 100 pills, bb's and peanut butter jars in a RCBS vib tumbler, Scenars 1 hour, everything else 30 minutes. </div></div>

Did your order take forever to arrive? Mine has been in transit since the 16th.

 

[Ted_D]

Re: School me on hBN

mine took about 10 days