What results with HBN or Moly coated bullets?

[benchracer]

For those who coat their bullets with Moly or HBN, how much did you have to increase the powder charge, on average, to get your original velocity back (vs uncoated bullets) and how much additional velocity were you able to get before reaching pressure limits with the coated bullets?

 

[gohring3006]

Tag.
This sounds like a good question for Shane .(montanamarine)
I'm also interested in this question especially in 30-06.

 

[Deleted member 46119]

I hBN coat almost everything.

Not doing the Nosler wildcats yet as I don't want to skew the data.

but to your question.

I really didn't notice enough difference. Now it's been so long I probably wouldn't be able to find any recipes with out it.

I guess I'll add a before and after hBN to the Nosler wildcat testing since that is purely for the data and throwing things that fast should show friction changes well.

 

[benchracer]

I guess I'll add a before and after hBN to the Nosler wildcat testing since that is purely for the data and throwing things that fast should show friction changes well.

That would make for a very useful comparison. Thank you for adding that to your testing!

 

[benchracer]

Tag.
This sounds like a good question for Shane .(montanamarine)
I'm also interested in this question especially in 30-06.

It was actually something that montanamarine wrote that got me to thinking about this. In one of his posts about the 208 AMAX in 30-06 or .308, he mentioned that he felt using moly is what was allowing him to reach the powder charges and velocities he was seeing.

That got my attention, because he was getting velocities from short barrels that I wasn't certain I could reach from a 26" barrel.

Which led me to think about this...

Since I have recently begun to incorporate OBT calculations in my load development process, I tend to look for bullet/powder combinations where the highest node comes in just below max. With certain bullets, the node I would really like to reach is just BARELY over max. In cases like that, I typically back down to the next highest node, which often costs me more than 100 fps.

In a lot of cases, I wouldn't need a lot of headroom to reach the next node. If HBN or Moly would allow a very slight bump in velocity at safe pressures (on the order of 50 fps or so), it would put some very interesting possibilities in reach and, perhaps, give me a bit of cushion with loads that are near max.

I am very seriously considering some experiments with HBN, in particular, but I would like to get input from folks who have experience with this stuff. That might give me an idea of whether or not my thinking is realistic.

 

[gohring3006]

If I could reach a accurate load with the velocities he's getting out of the 208 it would make the ol '06 a true 1000 yard hunting gun. If I could get my hands on some 215 hybrids I would like to see the results moly'd behind some RL 17...

 

[benchracer]

I plan to do the same in my .308 with the 208 AMAX, which is probably on the edge of stability in my 12 twist barrel. I am also looking to apply those same principles to some other chamberings. If I can make the concept work elsewhere, I believe the end results will be surprising.

BTW, I just bought some 215 Hybrids the other day from Midway. I don't think I will be able to stabilize them from my .308, but I have a .300 Win Mag getting ready to go together that should handle them, no problem. I will be testing 208 AMAX, 215 Hybrids, and 230 Hybrids in that rifle when it is ready to go. It would be interesting to try those same bullets in a 10 twist 30-06. The '06 might even have enough case capacity to allow for slower powders than RL-17 with the heavies, which would have the potential to open a significant gap in performance over most .308's.

 

[gohring3006]

I plan to do the same in my .308 with the 208 AMAX, which is probably on the edge of stability in my 12 twist barrel. I am also looking to apply those same principles to some other chamberings. If I can make the concept work elsewhere, I believe the end results will be surprising.

I do know my father in law was able to push a moly'd 58gr vmax to 4000fps in a .243. He thinks he could have pushed harder but he thought 4000 was fast enough. Haha
I was also wondering if barrel life is better, same or worst..

 

[benchracer]

I do know my father in law was able to push a moly'd 58gr vmax to 4000fps in a .243. He thinks he could have pushed harder but he thought 4000 was fast enough. Haha
I was also wondering if barrel life is better, same or worst..

In his writings on the subject, David Tubb seems to believe that both Moly and HBN can significantly extend barrel life. I can especially see where that would be useful and important for someone shooting competitively.

For the chamberings and applications I am looking at, effects on barrel life are of less importance to me, but I have a few rifles that could benefit from that. It would be interesting to see, for example, how far barrel life could be extended in chamberings like 6.5-284, .264 Win Mag, and 22-250 with melonite treated barrels and coated bullets.

 

[gohring3006]

In his writings on the subject, David Tubb seems to believe that both Moly and HBN can significantly extend barrel life. I can especially see where that would be useful and important for someone shooting competitively.

For the chamberings and applications I am looking at, effects on barrel life are of less importance to me, but I have a few rifles that could benefit from that. It would be interesting to see, for example, how far barrel life could be extended in chamberings like 6.5-284, .264 Win Mag, and 22-250 with melonite treated barrels and coated bullets.

My father in law seems to think the same. He always runs his guns hot, whether it is pistols or rifles and shooting hot varmint loads out of his .243s took its toll on the throats.
I never gave it much thought till now,

 

[Deleted member 46119]

...

Since I have recently begun to incorporate OBT calculations in my load development process, I tend to look for bullet/powder combinations where the highest node comes in just below max. With certain bullets, the node I would really like to reach is just BARELY over max. In cases like that, I typically back down to the next highest node, which often costs me more than 100 fps.
...

Yes, sometimes for me, the faster node is just beyond my comfort zone so I'm with you on that. Proofing the hBN reduction in pressure and increase in velocity would be very good data for all of us.

I have to get through 56 more rounds of a fairly big magnum with the Pressure Trace, then repeat the first 28 I shot without it.

The 26-Nosler wildcats are very stout magnums. 28 rounds, even over the 3 hours and throw in 50 rounds of 6BR to kill time so I didn't kill my barrels and the testing day was a physical experience. Oh and of course my 5 shot strings with the BR had flyers from some very nice groups. Imagine that....gun)

 

[Capt RB]

I've been been using molly for about 15 yrs. I'm interested to see your results. I have been using it in a 243 as well as 270 and 30 cal.

 

[kadrick]

3 issues I found in using HBN. 1. Bullets show increase in force needed to seat. 2. Pulled bullets show gouging scratches unlike graphite coated necks. 3. Velocity loss compared to naked or WS2 bullets

 

[Mikecr]

I know nothing about HBN, but it's important to understand that moly does not lower MV due to friction change.
Instead, with moly, there is a cooling of the charge as moly vaporizes.
This does reduce land erosion, but unless moly is managed perfectly, accurate barrel life itself goes down.

For sure HBN would not have the exact same affect.
WS2 has a far lower friction coeff than moly, and it does not affect MV at all.