HbN and odd result?

[rogn]

I had never used HbN before but have used WS2 for years with excellent results. I decided to try the Boron compound just to keep things cleaner and avoid any potential Rxn of the sulfur component. I also noticed some WS2 loads sticking after long storage.
I came into a Howa 300 WM by some stupidity on my own and found it to be prone to putting all shots into one slightly ragged hole. I figured this would be a good candidate for boron so I treated some bullets and cleaned the bore and swabbed it with alcohol boron. It turned it into a 2-3" rifle. Tried several of the earlier successful loads with the same disappointment. Finally cleaned the bore and loaded some clean/untreated bullets and shot a bit after 3 foulers the grouping seems to have returned to the formed level of precision.
Anyone else seen this kind of results?

 

[JRS]

Increase the powder charge weight.

 

[jimcasey01]

I had never used HbN before but have used WS2 for years with excellent results. I decided to try the Boron compound just to keep things cleaner and avoid any potential Rxn of the sulfur component. I also noticed some WS2 loads sticking after long storage.
I came into a Howa 300 WM by some stupidity on my own and found it to be prone to putting all shots into one slightly ragged hole. I figured this would be a good candidate for boron so I treated some bullets and cleaned the bore and swabbed it with alcohol boron. It turned it into a 2-3" rifle. Tried several of the earlier successful loads with the same disappointment. Finally cleaned the bore and loaded some clean/untreated bullets and shot a bit after 3 foulers the grouping seems to have returned to the formed level of precision.
Anyone else seen this kind of results?

Sounds like you need to do a new charge weight test with the Hbn coating.

 

[johnmyers]

Sounds like you need to do a new charge weight test with the Hbn coating.

What Jim said. You will probably have to up your charge a little with HBN

 

[rogn]

"increase charge"- thats somewhat puzzling because prior to boron treating the charge/ velocity seemed to have little, limited influence on group sizes?

 

[JRS]

Are you using a chronograph to verify the velocity?

 

[nmkid]

Perhaps you should read this.

http://www.6mmbr.com/bulletcoating.html

 

[GSPV]

One ragged hole to 2-3” isn’t the load going out of tune due to the typical loss of velocity when going to HBN. It’s something else. If WS2 or naked works, stay there.

 

[Capt. Oblivious]

You changed a component so you have to start load development again, it might not be much work but it will need a bit of work but as GSPV said unless you dropped allot of speed it sounds od. Did you give the bullets a lite polish after coating them, you might even need to go up a size in bushing if your using a bushing

 

[Dusty Stevens]

Looks to me like the rifle is telling you to make it easy on yourself and not coat the bullets

 

[normmatzen]

Two things;

1. the hBN will change your Mv down a bit and
Re-characterize your load to find a new good load,
2. You may be using too much hBN to coat the bullets. Too much on the bullets will make them VERY random! I use a scant medium flat bladed screw driver for a spoon and put that in a glass jar with about 1.5-2" of tin plated steel BB's for 35 or so bullets and run in the vibrator for 1.5 hr. Then I put the coated bullets in media and vibrate for 15-20 min to take off the surface hBN as all you want is a light layer embedded into the cladding, and nil to none on the actual surface. For coating the bore after cleaning, I have a oily patch with a coating of hBN I run through once. My results have improved markedly since the final media clean.

 

[wedgy]

You are also changing the neck tension, as someone noted you may have to go to a tighter bushing if using bushings. Also noted, you are also lowering the velocity(usually 30-50fps) so a powder increase is needed to put you back in your node.
Use a backed off charge for the 1st shot or 2 after swabbing the bore as it tends to have a bit more pressure for the fouling shots.

 

[GSPV]

Gentlemen, losing 50 FPS and going out of tune isn’t going to take a rifle from one ragged hole to 2-3”. More like one hole to three holes touching stacked vertically.

I’ve shot a whole bunch of HBN coated bullets. There was never anything like that going on.

There is something else going on here. I’m guessing some misstep(s) in the HBN process.

 

[JRS]

There is much better uses for hBN than using it on bullets.

 

[GSPV]

I stopped using HBN just to eliminate a variable. It made my cleaning a little easier. I’ll put up with a little more cleaning to completely eliminate a variable.

 

[rogn]

I havent tried any fuirther use of HbN but reading some of the replies, the most likely factor I can see is that the coating or application therein may be too thick or too random. I did a bit of rolling of the bullets in a towel but didnt get too involved. The amount of boron I used was more than a dab on the tip of a screwdriver. A lot more. I think I was looking for a resdily apparent layer like with WS2. I had a readily apparent layer. !!? I may try this rifle for deer hunting then later resume tryin out the HbN coating.

 

[T-shooter]

You can read my test, with pictures, and decide for yourself.
http://forum.accurateshooter.com/threads/hbn-not-for-me.3931997/

 

[Rustytigwire]

Lower friction .5 micron Hbn with 224 dia 50 gr Vmax inside a 5 inch cube plastic bottle inside thumblers tumbler, with hard steel shot bb size.
Finish on bullets came out well enough.
Same setup with 55 grain Sierra Blitz King. I got ammonia smell.
Now i wet a cloth with isopropyl alcohol and hand squish bullets all round a bit first to clean off whatever lurks. Next in a pan and get them too hot to hold via hair dryer before they get tumbled.
No more smell.
End result?
Less barrel fouling.
No numbers or data on any ballistic value.
Tom