After a 10 year wait.............. Its coming!

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15 years 3 months ago #1990 by weshowe
Replied by weshowe on topic Re:After a 10 year wait.............. Its coming!
zfk55,

I'm going to show my ignorance...what's hBN? Another term for "moly" or a new process without the issues we see with moly coating?

I'm going to pull my MK4 M1 LR off my .223 varmint rig and put it on the GAP rifle in the near future. I want to do some more work with the rifle before I make that final decision. It's got a 6.5 X 20 Nikon on it that I really like and it tracks well. Wish the guys at Leupold would take a few notes from the other makers and start using metal(steel)for some of their internals rather than plastic that wears...

The rifle is broken down now. Clean and reassemble tomorrow for Friday's sighting in and chronograph session.

Wes

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15 years 3 months ago - 15 years 1 week ago #1992 by zfk55
Replied by zfk55 on topic Re:After a 10 year wait.............. Its coming!
Wes, its hexagonal Boron Nitride, a whole different critter. David Tubbs (among many others) is now calling it the end-all for projectile and bore burnishing. He provides a service for hBN impact coating at $0.05 per bullet.
Read this one first, and I can tell you that my Son's 22-250 groups went immediately from a nominal 1"+ right down to .34"

www.patentstorm.us/patents/7197986/description.html
Last edit: 15 years 1 week ago by zfk55.
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15 years 3 months ago #1993 by Edge
Replied by Edge on topic Re:After a 10 year wait.............. Its coming!
I think you just about have me convinced. Where do you order this stuff from?

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15 years 3 months ago #1994 by zfk55
Replied by zfk55 on topic Re:After a 10 year wait.............. Its coming!
Edge, the minimum is 1 pound, and that should handle about 300,000 .30 caliber projectiles.
Go here......... sandblastingabrasives.com/contact-us.html?action=success

zfk55
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15 years 3 months ago #1995 by Edge
Replied by Edge on topic Re:After a 10 year wait.............. Its coming!
zfk55,

Which micron size do you use?

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15 years 3 months ago #1996 by zfk55
Replied by zfk55 on topic Re:After a 10 year wait.............. Its coming!
Negative 5. After a lot of pre-purchase research we determined that the -5 is the most commonly used and is typical for barrel burnishing. When you get ready to do that, let me know. We'll walk through the necessary steps.

zfk55

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15 years 3 months ago #1997 by zfk55
Replied by zfk55 on topic Re:After a 10 year wait.............. Its coming!
And if you do a pre and post chrono on your typical load you'll find that the projectile velocity difference is quite notable and chamber pressures are going to drop with the treated bore and projectiles.

zfk55

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15 years 3 months ago #1998 by Edge
Replied by Edge on topic Re:After a 10 year wait.............. Its coming!
Thanks! I'll let you know when I get it in.

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15 years 3 months ago #2010 by zfk55
Replied by zfk55 on topic Re:After a 10 year wait.............. Its coming!
Latest info.

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. Targets to follow later.
zfk55
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15 years 3 months ago #2011 by Edge
Replied by Edge on topic Re:After a 10 year wait.............. Its coming!
Bummer......but, I'm glad that you figured it out!

So have you ever tried coating Nosler partitions? I'm just wondering if the plastic tips would be damaged.

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