For those of you who cast your own projectiles I have a little tale of woe for you. I shoot a Ruger Mk II .35 whelen. I had a great load for it. A hard cast RCBS .35 cal. 200 gr. FN bullet propelled by 63.0 grs. of W748, in R-P brass, sparked by a WLRM primer. Velocity chronied at 2700+ fps with MOA accuracy for 3 shots at 100 yds. I was pumped to send one of those babies thru some unsuspecting bucks ribcage this past hunting season. I had been shooting this load all year with the above results. Two weeks prior to hunting season, I go to the range to re-check my zero. MOA groups were now 3-4 inches. Normal primers were now flattened, with a few that actually pierced. Besides being disappointed in not being able to use the .35 whelen for the hunt(I wouldn't feel good about possibly crippling a deer with such inconsistant results), I had to stop, and scratch my oversized head. What went wrong ? I used the same everything. Brass, bullets, primers, same powder lot. Then it dawned on me! Yep, I was the victim of inadvertant age softening. I water quench my cast bullets made of straight WW. This produces BHN of 21-22. When my bullets were shot at this velocity, there was no trace of leading what-so-ever. As the bullets softened over a 1 1/2-2 yr. period, they softened enough to raise pressures, and throw accuracy out the window. Mystery solved ! Something to look out for. Never had any problems with age softening with water quenched cast bullets in any other gun where velocities are kept around 2200-2300 fps. The 2700 fps velocity was about peak pressure for the as cast bullets. Age softening had affected a safe max. load for me. So, for now on, only fresh cast(1 yr. or less) bullets for this cowboy, for high velocity loads. This was a good learning experience for me, and I hope for you, also. Good casting! Jeff

Wow never heard of that. I don`t drop mine in water. Will they soften also.?

Air dropped bullets stabilize in a week, and heat -treated wheelweight softens to air-dropped hardness in time, IF I've got it right. I don't know what alloy Beartooth uses, but it is stable. You need some tin and arsenic for a stable hardenable wheelweight alloy, but I don't have the percentages handy.

Bye
Jack

One of the loading manuals that just didn't sell well was the RCBS Cast Bullet Manual...but they have a short section on Hardness adn Aging effects.

"Following heat treatment, the hardness of the bullet will undergo changes which cn be summarized as follows: after quenching, bullets reach peak hardness in 1 to 10 days. Hardness will then slowly decline over a peroid of one to three years after which it will remain nearly constant."

"Lead containing about 1% antimony....has an as case hardness of about 8 BHN. Heat treatment increases the hardness to 19- 20 BHN about 10days after quenching. Thereafter, the hardness declines to about 17 BHN after one year."

Goes on to note that alloy with 2.5-6% antimony can quench to a peak hardness of 28-36 BHN, and reaches that peak one day after quenching...declines to about the middle-20 in ayear...and stablizes at somehwere between 19 nad 22 BHN after two to three years.

I've always wondered... If you reheat-treat your bullets in the oven, will that restore your hardness, once your bullets were treated once and the hardness "faded"? ==Bob

I've seen it mentioned in the past that in order for the cast lead bullet to stabilize permanently at a given BHN it is necessary to have some arsenic in the mix. Apparently it is not a high amount. Per a previous post by Marshall his alloy contains .25% arsenic; and I've seen it posted elsewhere that a "cup" full of lead shot mixed in is all it takes. Can anybody confirm this?

Pourboy, there is no reason you should not be able to re-heat-treat the bullets, unless they are lubed already and your family members don't care for smell of baked bullet lube.....

If you're single, SURE!

Depends on what manual you read...some claim that any more than 1/2% does no good and can lead to surface defects...others are less specific and claim that as much as 10% of the melt can be from shot. That last is hard to make into a percentage of Arsenic as shot's percentage varies and the amount of actual metal is less than you'd think by weight as shot has a lot of oxidized or graphite covered surface area.

A oldtimer told me that cast bullets stored in the freezer wont soften over time.
Leon