What hardness for rifle loads ?

[hylander]

I have searched but didn't find an answer.
I'm loading 185gr. GC boolit for the 30-06 going around 1700 - 1800 fps.
What would be the hardness range I'm looking for ?
I have been casting WW/water dropping and WW/air cooling, what might be the hardness difference between the two.
I know there are variables but where do I start, is there a table somewhere ?

[Bullshop]

1700 to 1800 fps I have had good luck with alloy at 13 to 15 bhn. The velocity is not as criticle as the pressure. You can get that velocity at a wide pressure range depending on the powder burn rate you use. The lower the pressure the softer the alloy can be to still get good accuracy
WW now generally run about 10 air cooled. WW quenched if they are hot enough and you use ice water I have gotten them to over 20 bhn.

[hylander]

1700 to 1800 fps I have had good luck with alloy at 13 to 15 bhn. The velocity is not as criticle as the pressure. You can get that velocity at a wide pressure range depending on the powder burn rate you use. The lower the pressure the softer the alloy can be to still get good accuracy
WW now generally run about 10 air cooled. WW quenched if they are hot enough and you use ice water I have gotten them to over 20 bhn.

Thanks,
I have been water dropping into room temp water.
Also using 18gr. 2400

[detox]

Mike Venturino one of the writers of Handloader magazine uses linotype (22 bhn) in his military surplus rifles. He also uses the soft SPG lube. You can read his latest artical concerning this in April 2013 issue on news stands now.

Linotype is veryeasy to cast with. Usually around 600-650 degrees. Makes purdy boollits

[DrCaveman]

I obsessed with hardness for a while. Due to some insights gained here regarding boolit fit and lower-pressure powder use, i have basically forgotten about it. In my recent attempts to get past 2200 fps or so in my 30-30 and 30-06 i have some water dropped curing. Its been a few weeks so they are prob up to 20-25 bhn. I should check tonight.

Same alloy (pretty much COWW) was shot above 2k with no problems related to boolit hardness. Im definitely not a rifle loading expert but it seems that too much focus is given to hardness.

Besides, you will get better boolit expansion with a little softer alloy. The gas check and boolit obturation are keeping the lead fouling away, for me anyway

[runfiverun]

i'm sure what you are doing is working.
I use the exact same formula for most of my rifle loads.
18 grs of 2400 and a water dropped boolit.

I haven't met a piece of paper, rock, ground squirrel, grouse, or deer that hasn't been handled by this combination yet.

[rintinglen]

I heat treat my boolits when I want them to go fast and usually end up 24-28 bhn. There's them as holds that fit is king and a good enough fittin' boolit will do just fine, no matter how soft. I agree that fit is most important, but I find that once you get much beyond the 1800 fps mark, accuracy suffers and leading starts unless your boolits are harder than the typical WW air cooled. I do not water drop because it is easier to size soft boolits than hard ones. I size and seat gas checks, then heat treat using Dennis Marshall's technique. Since all the boolits hit the ice water at the same time, they all tend to be about the same hardness.

[shredder]

I also use the same velocity but cast my boolits a bit softer than yours. I have cast and shot many 50/50 WW and pure lead boolits to 1700+ (air cooled gas checked). I have no idea what the BHN of that alloy is but it does work well in my rifles and leaves virtually spotless bores with speed green. I have also cast with Lyman #2 which is much harder, and honestly I do not see much if any improvement in accuracy at those velocities, in my rifles. The boolits cast better and look better with lino or #2 and do cast slightly bigger.

IMHO, go ahead and use the straight air cooled WW alloy. It will give good results at those velocities.

[oldandslow]

hylander, 4/26/13

I'm working on a 180 grain gas checked boolit for my 30-06 and 30-30 (Accurate mold).

BHN numbers for air cooled and water cooled (oven heat method to 465 deg. for 60 minutes), WW plus 1-2% tin

Air cooled at 48 hours- 8.2
HT and drop in 70 degree water- 16.6 at 48 hours
HT and drop into ice water- 20.9.

All above are measured multiple times with the Lee hardness tester.

good luck- oldandslow

[hylander]

hylander, 4/26/13

I'm working on a 180 grain gas checked boolit for my 30-06 and 30-30 (Accurate mold).

BHN numbers for air cooled and water cooled (oven heat method to 465 deg. for 60 minutes), WW plus 1-2% tin

Air cooled at 48 hours- 8.2
HT and drop in 70 degree water- 16.6 at 48 hours
HT and drop into ice water- 20.9.

All above are measured multiple times with the Lee hardness tester.

good luck- oldandslow

A little confused,
You are using WW + 1-2% Tin, correct ?
And it is air cooled at 8.2 BHN
I thought WW were more like 11 - 12 BHN alone

[mpmarty]

With the COWW we get now the hardness can be anywhere and trial and error will show what you have.

[runfiverun]

remember he measured them at 48 hours if he showed his numbers at 10 day's things would be different.

[Shiloh]

What do you suppose 50/50 WW/Range Lead is?? Thats what I use for about everything. No faster than 1825 in rifle or 1300 in handgun. No issues.

Shiloh

[oldandslow]

Hylander,
Regarding the expected BHN of wheel weights. As others have noted the consistency of WW may vary over time and location. Lyman's "Bullet Making Guide" lists wheel weight's BHN of 9 (95.5% lead, 0.5% tin, 4% antimony) so my AC WW BHN of 8.2 seems reasonable. Good luck.
best wishes- oldandslow

[Larry Gibson]

hylander

COWWs generally lack sufficient tin. Add 2% tin and you'll get 14 - 17 BHn from AC'd bullets after 7 - 10 days aging. If it's a good batch of COWWs (never know until you try them) the BHN will general be 16 - 17 after the 10 days aging. WQ'd can get you 18 - 24 BHN with the 2% tin added again depending on the quality of the batch (% of lead, antimony and tin). The AC'd bullets will be good for 2200+ fps if the rifling twist is right and a slower burning powder used. The WQ'd can be pushed to 2600+ with very good accuracy, again if the variables are correct. If what you're doing is working then it isn't broke so don't fix it. However, the added 2% tin makes a better alloy and will cast better also.

Larry Gibson

[MtGun44]

Clip on wwts plus a touch of tin runs about 12-14 BHN in my experience and has worked without
heat treatment just fine in pistols, mag pistols and rifles up to about 1800-1900 fps
without any problems. I am using GCs on the great majority of the rifle
loads. In my experience, hardness is something most casters seem to spend
way too much time worrying about.

This whole "hard cast" thing is largely misunderstanding based on Keith
recommending "hard cast" boolits for .44 Mag. His "hard cast" was a straight
tin-lead alloy with one part tin to 16 parts lead. This alloy is reported to
cast at BHN 11, about the low end of air cooled clip on wwts. So anyone
casting with air cooled wheel weight alloy (AC WWt) is probably running
boolits that are harder than what Elmer called "hard cast". I think in his
day he was comparing to pure lead used in a lot of ammo, even factory
boolits.

Of course, the advantage to linotype is that it casts very nicely - probably
due to the tin content. The hardness is not necessary for most shooting
applications, and since lino is brittle and will shatter on impact, it is
a poor hunting alloy.

Don't sweat it too much.

Bill

[303Guy]

I did some simple tests using different powder charges to find a point at which the centre of the boolit gets expanded into the bore but not the area immediately behind the ogive. The aim was to avoid base damage. The alloy was a sort of medium hardness copper tin. The one that did expand in the middle also suffered dragging at the rifling impressions but I can't tell how even that dragging is. If even then no problem.

68576

Those were paper patched boolits so the paper would have supported the mid-section but may not have been able to align the boolit perfectly - I don't know. One can see how the knurling has been ironed out on the second one. I cannot repeat the test with plain lube because I don't have a two-diameter sizer for plain lube.

Anyway, the trick is match alloy strength with pressure so the nose doesn't slump. The shorter the unsupported nose the higher the pressure (more or less).