does HBN also reduce the charge like moly?

[Mag 300]

reading loads for a rifle from David Tubb he says if using moly bullets ise 1.5 grains less powder . would this be the same for HBN???

it would seem so ??????????????????

 

[JRose]

Re: does HBN also reduce the charge like moly?

This is just me, but I had to increase the powder charge...

I loaded two sets of test bullets before I switched over to hBN, both had the exact same powder charge of H4350, from the same lot, the hBN load was 40 fps slower than the naked.

But the pressure signs were considerably lower in the hBN loads.

 

[Mag 300]

Re: does HBN also reduce the charge like moly?

WOWE
Not what I would have thought pressure lower "sure" fps lower???

Thanks I will validate this some time in the near future .

Bill

 

[JRose]

Re: does HBN also reduce the charge like moly?

I wasn't expecting it either Bill.

 

[Country]

Re: does HBN also reduce the charge like moly?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bill Stoffels</div><div class="ubbcode-body">reading loads for a rifle from David Tubb he says if using moly bullets ise 1.5 grains less powder . would this be the same for HBN???

it would seem so ?????????????????? </div></div>
This is not correct . When you use a good pure MOs2 Moly coating it reduces velocity so you have to increase the powder load slightly to get back to normal velocity.
I am sorry I can't say what HBN does because I don't use it.
However I would suspect from the comments above that it acts similar to Moly MOs2 .
Because the bullet moves down the barrel easier ( less friction) and has less engraving from the lands so less obtruation then the powder sees a greater volume to time ratio compared to a bullet with more friction . So the effect is that the bullet gets less speed imparted to it . Thats a laymans explanation but I have spent 25 years molycoating bullets and doing experiments so even though I can't give a scientific explanation I know for a fact that Moly slows the bullet down for the same powder charge. It sound crazy I know but thats what I have found.

 

[Ted_D]

Re: does HBN also reduce the charge like moly?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bill Stoffels</div><div class="ubbcode-body">reading loads for a rifle from David Tubb he says if using moly bullets ise 1.5 grains less powder . would this be the same for HBN???

it would seem so ?????????????????? </div></div>

1.5 grains more for me

 

[Mag 300]

Re: does HBN also reduce the charge like moly?

Thanks for all the help, I went back to the site and it does say
REDUCE LOAD BY 1.5 grains if using non coated bullets

So it would be an increase to the Hbn and the moly had that backwards

Bill

 

[Country]

Re: does HBN also reduce the charge like moly?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bill Stoffels</div><div class="ubbcode-body">Thanks for all the help, I went back to the site and it does say
REDUCE LOAD BY 1.5 grains if using non coated bullets

So it would be an increase to the Hbn and the moly had that backwards

Bill </div></div> That sounds a lot better .

 

[Mag 300]

Re: does HBN also reduce the charge like moly?

Thanks
Back on track now

Bill