Can a cast bullet said to have a BHN of 16 be pushed to around 1100~1200FPS without lead fouling the bore?

Thanks

Yes. It can.

Or, it could lead like the very devil if it has the wrong lube or is undersize for the bore. Believe it or not, hardness is the least important factor when it comes to leading.

I have been casting for over 45 years and both of the above posters are correct. Bore leading can be caused by either one or by a combination of both. Bore smoothness can also contribute.


PS I just reread what I posted. The "either or" refers to bore size or the lube not the above posters. :-0

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Semper FI

You do not mention any lube on that chunk of lead, so the answer is no. Even with proper lube, that still is "probably not" the best choice for bullet hardness.

If anything, that might be too hard to properly obturate to assist in sealing the bore, but that depends on the caliber and the pressures it generates. 1440 x 16 = 23040 psi.

A S&W 500 shooting 440gr can produce 3 times the pressure of a 125gr 38 spl at same 1200fps velocity, with desired bullet hardness changing from 22+ BHN in the 500, to less than 12 BHN for the 38 spl at that velocity.

Correct size to slugged barrel comes first. And "usually", softer is better than harder bullets.

Cast bullet alloy's and bullet obturation

Google "From Ingot To Target".

This will answer many questions and maybe even raise more.

Its a great set of articles concerning BARREL LEADING CAUSES AND FIXES,

BULLET CASTING, BULLET HARDNESS RANGES and other related topics.

Expert advise is just wonderful.

Do youself a favor and give it a look.

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NRA Pistol/Rifle Inst. RSO

The bullet hardness thing has been soooooooo over rate for the last decade+. Commercial bullet casters/makers use 1 bullet hardness fits all concepts because they don’t know what the people buying their products are going to be loading them to. It’s just easier to use 1 lead alloy for everything & they do the same thing with the hard lube that they use.

I’ve loaded/shot bullets up to 1400fps cast out of soft alloy (10bhn) & air cooled in 357’s and 44mag’s with no leading issues at all. A good fit & an excellent lube are what counts with cast bullets. I use the same alloy & lube for all my cast bullets, anything from hbwc’s to hp’s to swc’s to hg 68’s for the 45acp in anything from 38spl to 44mag.

I will however use the same alloy & water drop/cool them to make them harder for the 30-06. These I run in the 1600 to 1800fps range using the same lube & have had no leading issues at all. But again a good bullet/bbl fit along with an excellent lube is what it takes.

Everyone has a preference on what lube they like or soft/hard lubes in general. Myself I make my own lube & like a soft tacky lube that’s made from good quality products. I can’t size/lube a bunch of bullets with this lube & store them in a coffee can or other similar container because the lube is so soft & sticky it will pull out of the lube grooves & stick to the sides of the other bullets. I view bullet lube as a gasket that seals the bore like a piston ring on a piston along with lubing the bore. When I’m done with a shooting session I will see a star pattern on the muzzle of the firearm that is made out of lube. That’s a good thing, every time I see that I know the lube did its job.

Guys thanks for the reply(s)

I kinda suspected there was a bit more to it when I asked, what
Prompted me was I saw some cast bullets listed in the accessories
section the other day and I want to get some to load over the winter
months, so maybe an easier question might be is where can I find some cast
I can use in 357 that won't cause me any grief.

It's rarely the alloy hardness but almost always the bullet fit, then the lube, then the BHN. I have run 18BHN bullets in my 45-70 @ 1600fps w/. no leading. My hunting bullet in the 44mag is a soft 25-1, lead/tin cup point that does not lead @ 1250fps. SO slug the cyl throats, then the bore, then get a bullet sized 0.001" larger, alloy won't matter much to just shy of 1400fps.
BTW, if the cyl throats are smaller than the bore, you'll likely get leading regardless fo alloy or vel. The bullet will swage down passign thru the cyl then have to bump up as it hits the larger bore. You'll get leading, if it's a harder bullet, maybe more leading as it will be slower to bump up if at all.