Friday, August 17, 2012

Lead Bullet Hardness

We are often asked by a customer "How hard are your lead bullets?" When we answer "14 to 16 on the SAECO scale", we see a nod, but are never sure that the information we are putting out is actually getting through. People often don't know either what the SAECO is, or don't know what that number means.

The SAECO Scale
SAECO is one of the premier manufacturers of casting equipment for individual use. While we use almost exclusively Magma Engineering equipment to cast our bullets, SAECO still makes very good quality ancillary products, including their hardness scale.

SAECO's Hardness Tester
SAECO's hardness tester easily allows casters to test the hardness of their alloyed bullets. It uses their own scale to determine the hardness, where a pure lead bullet is scored at "0". A bullet alloyed with wheel-weights, the hardness that most hand-casters use, scored at 8.

To give a good example of how hard our bullets are in comparison to other bullets styles of bullets on the market, we tested three of the most common pistol bullet styles available: jacketed/plated, moly coated, and hard-cast lead.

Jacketed and Plated Bullets
By far, the most commonly available bullet used in off the shelf ammunition is a full-metal jacket bullet. For hand-loaders and reloaders, plated bullets offer a less expensive alternative. Both work well, and are good bullets in their own accord. We tested these, because customers have often had bad results with lead bullets, and we wanted a baseline measurement to compare.We decided to combine the results for jacketed and plated bullets, as a good quality plated bullet will be almost identical to a jacketed bullet. The only major difference is how the copper crust is applied.

Testing a plated bullet
We sampled 10 bullets from both Hornady 9mm 115gr Jacketed bullets, and the Frontier 9mm 124gr Plated bullets found on our website. Of the 10 bullets we tested, they averaged out to 18 on the SAECO scale.

Moly Coated Lead Bullets
Moly Coated Lead Bullet
Moly coated bullets seem to wax and wain in popularity. One year they are the greatest thing in the world, and everyone wants us to make them, and the next year, we don't hear a peep about them. The concept behind the moly coating is like that of heat treating bullets: by putting a hard coating on the outside of the bullet, a less-expensive alloy can be used to push a bullet to faster velocities.

Testing the Moly Coated Lead Bullet
Like the jacketed and plated bullets, we sampled 10 bullets to find the hardness. We didn't know the manufacturer of these bullets, but it seems that they were using a softer alloy, as the hardness was only a 10. This was not surprising as the tester uses a small pin-like device to hold the tip of the bullet in place, and most pierced through the moly-coating. This reinforces what we've been telling customers for quite a while: the moly coating will not necessarily decrease the amount of leading in the barrel, as the rifling will most cut the moly coating, exposing the lead, and putting the potential of lead smearing.

Our Hard Cast Lead Bullets
And of course, we had to test our own hard cast lead bullets. We already test these when coming off of the casting machine for hardness, with a hardness goal of between 8 and 10 on the SAECO scale. We then allow our bullets to cure for 3 weeks before we package and sell them.

Testing Slash K's Hard Cast Bullet
We tested a 10 9mm 115gr Round Nose bullets that we cast 3 weeks ago, just before we packaged it. They averaged 15 on the SAECO scale, with almost no deviation.

What about the Brinell Scale?
A Brinell to SAECO conversion chart
In most other industries, the Brinell scale is used to measure the hardness of a material, so we are often asked about the Brinell hardness of our bullets. There doesn't really exist an exact scale to compare the two numbers, but the chart included with SAECO's hardness tester gives a very good idea. As you can see on the chart, it bottoms out at measuring in the 12.0 SAECO range, but that offers a hardness of 35 on the Brinell scale. Since our bullets average 15, we are well above a 35 on the Brinell scale.

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