Which is more slippery, HBN or Moly?

[1KBR]

I have been trying to get my 284 working for a while now, and it goes well at 2830 fps, but it seems I have a tight or slow barrel or something. Extraction is hard at the speed it likes and primers get loose way to quick for me. Cases last OK and extraction is easy at 2780-2800 fps, but it just don't want to shoot at that speed.
I thinking of trying moly or HBN to get just a bit more speed to where its node is.
Is there any research on which coating is more slippery?

 

[Pres100]

Slippery is hardly a technical term, but HBN is smaller particles, I believe. Both are pretty slippery.

 

[madderg]

I think that 'wet' moly is the way to go, and it will settle in as the go-to application in the future. I sure swear by it now.

 

[bdale]

HBN is slipperier lower coefficient of friction.

 

[Matt P]

I would say your barrel is normal, I've had a few 284's and mine hurt cases at the "supposed" node at 2830, I run mine at 2750 with excellent accuracy and case life.
The difference in drift @ 1000 yrd with a 10MPH cross wind is 1/4 moa, which in my opinion is nothing.
You may get the extra velocity with moly or HBN (I prefer moly, I've had much more consistent results with moly) but is it really worth it ?
Matt P

 

[1KBR]

I would say your barrel is normal, I've had a few 284's and mine hurt cases at the "supposed" node at 2830, I run mine at 2750 with excellent accuracy and case life.
The difference in drift @ 1000 yrd with a 10MPH cross wind is 1/4 moa, which in my opinion is nothing.
You may get the extra velocity with moly or HBN (I prefer moly, I've had much more consistent results with moly) but is it really worth it ?
Matt P

I don't think I have run mine as low at 2750, but have gone down to 2770 and it was getting worse and worse as I got lower. I don't mind so much running at a slightly lower speed if it works well there, but another reason for wanting to run coated bullets is to reduce barrel temperatures. By the time I get to shot 17 or 18, accuracy starts to go out just enough to make it impossible to go clean at 900 and 1000yds. Looking at my records, It is nearly always my last 3 shots with this barrel which go into the 9 ring (or 8 ring if windage is factored in), even in perfect conditions. My previous barrel would keep on hammering after unlimited sighters (usually 3-5) and 20 shots.
This barrel also needs to be cleaned after the 2nd 20 shot string, so I was hoping to be able to go for the whole 3 strings with out cleaning like my previous barrel would.

 

[1KBR]

I think that 'wet' moly is the way to go, and it will settle in as the go-to application in the future. I sure swear by it now.

A buddy of mine showed me his wet mollied bullets and man they look sweet. Only thing worries me about molly is possible etching in the damp weather I get here.

 

[fredhorace77]

I think that 'wet' moly is the way to go, and it will settle in as the go-to application in the future. I sure swear by it now.

thats what they said when WD-40 came out

 

[Coolhand]

hbn is more slippery than moly but the difference is about the thickness of a gnat's pecker & IMHO not worth worrying about.
If you are worried about cleanliness go with hbn.
BTW , if you live and shoot in high humidity and using moly and don't clean , you MAY be inviting trouble. I forget the actual scientific explanation but the moly residue in an uncleaned barrel can attract moisture from the air , inviting disaster.

Mike

 

[ireload2]

The sulfur in the molydisulfide can combine with water vapor to create a small but concentrated amount of sulfuric acid which will attack even stainless steel.

hbn is more slippery than moly but the difference is about the thickness of a gnat's pecker & IMHO not worth worrying about.
If you are worried about cleanliness go with hbn.
BTW , if you live and shoot in high humidity and using moly and don't clean , you MAY be inviting trouble. I forget the actual scientific explanation but the moly residue in an uncleaned barrel can attract moisture from the air , inviting disaster.

Mike

 

[1KBR]

So, it seems there is not much difference between the two? I will likely try HBN first and see if it makes ES or SD worse. If it does, I will try moly and see how it goes.

 

[CPorter]

Like someone mentioned Moly with a little moisture and chamber heat can form sulfuric acid. I find tungsten disulfide is better than moly and if I remember right is slightly slicker than boron nitride. WS2 doesn't have the problems forming acid since it disassociates at much higher temperatures. From my experiences WS2 is a better coating but I use hBN because it is less messy... So WS2, then hBN, then Moly as far as lubricity.

 

[BigKev]

O.P. wrote:

Extraction is hard at the speed it likes and primers get loose way to quick for me. Cases last OK and extraction is easy at 2780-2800 fps, but it just don't want to shoot at that speed.
I thinking of trying moly or HBN to get just a bit more speed to where its node is.
Is there any research on which coating is more slippery?

While I cannot comment on the Moly I can tell you that if you use HBN (tried over several weeks) your total FPS will drop if you use the same loads (powder) and from your post it appears that you're at the high end of the load now as you claim to extraction issues at the load it likes. I hade to add 6 tenths of a grain of powder to my old load to get the FPS back up to where my bare bullets were running. Yes the HBN is so slick that you lose velocity and the trade off for me (prematurely destroying brass) wasn't worth the returns that I was seeing. Just my two cents and if you'd like some HBN powder to try send me a PM as I have a bit left over.

Kevin

 

[JHardy]

I am concerned regarding the very low velocity you are able to maintain as an accuracy node in your .284. I have had about 10 .284 Shehane barrels (yes, not exactly the same). One was 100 fps slower than the rest, and I could not find a "fix". 345 rounds later, I pulled that bad boy off my gun and used it as a fire forming barrel. You should be easily at 2825 range for an accuracy node with H4350 or H4831SC and a 180 class bullet with the straight .284 -- if your chamber is cut correctly for that bullet. If the barrel will not give you more -- toss it and get another barrel. Life is just too short to mess with it. Use it for fire forming if you like and consider the loss the cost and unintended consequence in your search for accuracy at a higher node.

Just my thoughts after suffering the same with a 32" prone barrel. The next barrel screwed on broke a long standing 1000 yard iron sight record.

BTW, all "slick" bullet coatings require a greater charge to reach the same velocity. That can give you better case volume and lower ES and SD -- in theory -- if your barrel is worth it in the first place.

Good luck,
Jim Hardy

 

[gaintwist]

I think that 'wet' moly is the way to go, and it will settle in as the go-to application in the future. I sure swear by it now.

Can you elaborate more on 'WET" Moly? I heard about using a water/Mo solution for applying it, is that what you refer to?

 

[JimPag]

HBN reduces friction better than Moly or WS2 but not by much.

 

[Capt. Oblivious]

Can you elaborate more on 'WET" Moly? I heard about using a water/Mo solution for applying it, is that what you refer to?

Drop the bullets in a container filled 40% or so with water and dump a spoon of moly in it. Seal the container and put it in your vibrating tumbler for 2 hours and rinse.

 

[Tuxedo007]

I don't think I have run mine as low at 2750, but have gone down to 2770 and it was getting worse and worse as I got lower. I don't mind so much running at a slightly lower speed if it works well there, but another reason for wanting to run coated bullets is to reduce barrel temperatures. By the time I get to shot 17 or 18, accuracy starts to go out just enough to make it impossible to go clean at 900 and 1000yds. Looking at my records, It is nearly always my last 3 shots with this barrel which go into the 9 ring (or 8 ring if windage is factored in), even in perfect conditions. My previous barrel would keep on hammering after unlimited sighters (usually 3-5) and 20 shots.
This barrel also needs to be cleaned after the 2nd 20 shot string, so I was hoping to be able to go for the whole 3 strings with out cleaning like my previous barrel would.

Different barrels mean different characteristics. Your new barrel will "tell" you its likes & dislikes, if you let it. Insisting on a certain velocity while ignoring all other factors won't help. You said in your other post that primers were loosening up too soon for you; that is a sign that you are running very high pressure! While moly may reduce barrel wear, extreme pressure & the cost of replacing cases will negate the advantages!

All barrels are different. You must find where the new barrel performs best, or consult the barrel maker &/or the smith who installed it. Or, you could go back to your old barrel since it appears that you like it so much better than the new one you currently have!

Why did you change out barrels?

 

[JRS]

Wet moly is a superficial coating. hBN, when correctly applied, is impact plated on the bullet jacket.

 

[Cuando]

Wet moly is a superficial coating. hBN, when correctly applied, is impact plated on the bullet jacket.

So where does this come into play? If hbn is incorrectly applied, what do you see? Shorter shot strings before cleaning? Poor accuracy? Higher ES and SD? What is the correct way to apply hbn? Does wet moly being a superficial coating mean it's not as good?