Brinell hardness of 38/357 cast bullets

[Alpha1]

Hi people what is the prefered brinell hardness of cast 38/357 bullets for 25 yard shooting in a underlever I'm thinking about 9. I have just bought some bullets that quote the brinell hardness as being 15.4 I think this is to hard and I'm inclined to chuck them in the smelter and add pure lead to bring them closer to 9.
What do you recon.

I had another interesting conversation the other night at the range with a guy older than me who has shot all his life and he can not get his underlever to shoot accurately with lead bullets. I'm amazed at how little he actually knew about shooting cast bullets and bullet fit etc.

[dromia]

If you have perfectly fitting bullets then the hardness really doesn't matter, linotytpe, monotype and the like (24+BHN) will all work and give excellent castability.

However perfect fit is hard to get unless the chamber/freebore and mould are cut to give that perfect fit.

So in the world of less than perfect fit softer alloys work better, BHN 9 will be just fine for underlevers, to be honest pure lead will work just fine for velocities up to around 1800 fps but the addittion of a little tin helps with the fill out so we end up with a slightly harder alloy.

Might be worth shooting some of the harder bullets just to see how they do, you never know the bullet shape and the freebore/ groove/bore fit might just be good enough to handle the harder alloy.

If you do check thoroughly for leading after each shot, if it does lead then you don't want to let it build up.

[Alpha1]

I was just going to chuck them in the pot and add pure lead but I will do as you suggest and shoot a few first.

[Beer Hunter]

Have to agree with dromia - I use pure lead with about 3% tin to lower the surface tension and let the mould fill out.
These test at BHN 10 with my Lee hardness tester (no idea if that is accurate, but it is repeatable which is all that counts) and after lots of experimentation perform the best in my .45 colt.

That sad, I'm only shooting at about 800 FPS and your .38/357 may be going a little quicker which could mean you want something a little harder.

I really believe the lube you choose is just as important as the hardness. A recent switch from Lyman "Ideal Bullet Lube" to Lyman "Black Powder Gold" shrunk my groups by a surprising amount and there was no leading of the barrel with either.

ATB,
Kev.

[dromia]

Soft alloys will shoot well up to at least 1800 fps. It isn't so much the hardness of the alloy that is important but its toughness which BHN is only a proxy for. With good bullet fit the alloys themselves won't lead passing through the barrel it is the shearing that occurs as the bullet enters the rifling at the higher velocities allowing gas to pass over the bullet thus giving gas cutting and leading. Gas checks are designed to stop this shearing and thus stop any leading. Usually harder alloys are antimony rich which as well as being hard makes the brittle but not tough, they are very prone to gas cutting leading if bullet fit is not perfect as the brittle alloy flakes a sit shears giving more area for gas cutting.

A good lube is important and alongside today's products the old Ideal lube is a bit wanting, for rifle loads most of the alox bases lubes are just fine I use White Label lubes mainly 2500. In my under lever rifle calibres - 44/40, 38/40 and 32/20 I use a simple black powder lube as I load these with black for full stoke loads, and with fast pistol powders for lighter loadings, a rule of thumb with lubes is stay away from most of the hard lubes. The thing about lubes is that their lubricating qualities is the least important thing with cast bullets, good fitting bullets don't need lubing to not friction lead, just look at black powder bullets the only purpose of the lube was to keep fouling soft, cap and ball revolvers use no lube at all back in the day neither did muzzle loading muskets. It is the hydraulic properties of the lube that does the work in helping keep the bullets shape and integrity as it accelerates down the barrel.

Get good bullet fit and the choice of lube is less important, it is the high velocity fast twist rounds and rifles that really sorts out the men from the boys when it comes to lube.