What is tempered lead shot?

Maybe not case hardened but copper plated shot would be close. Copper is harder than lead so it’s a bit like being case hardened, just not as pretty to look at! :)

No No I hear Yah FalconFlyer I was actually making a joke!
Really, taking an already hard shot like steel and hardening the surface even more while at the same time making it somewhat brittle Doesn't sound like a recipe for success for vintage shotgun barrels, But because case hardening is catch terminology for old guns I could see some marketing whiz coming up with the brilliant idea, and your right it just looks nice which is always a good sell! That's all :d

I'm all for copper plated or bismuth, and have no doubts re the science behind antimony content that's for sure!
 
I realized you were joking and attempted a bit of humour back, I’m just not that good at it!
Surface hardened steel shot would be a bit hard on vintage barrels alright, best to stick with the softer stuff for sure!

Sorry it took so long to get back but I’m over in Greece right now and I just got out of bed, it’s 0630 here.
 
RC cartridge from Italy uses tempered lead in their premium competition line and their products have won pretty much everything you can win with a shotgun. But then so has Kent Gamebore with their relatively low antimony Diamond shot.
 
AA Diamond grade is 8% Antimony. It's Copper plated, so not legal for ATA Trap.

That’s interesting, i knew they claimed it is the hardest shot available but I haven’t seen the specs for it. To think they added 8% and also copper plated the shot is a considerable step up in hardness. It kinda makes me think they’ve figured out that the 5.5% antimony in their AA ammo is still distorting somewhat in the barrel. I don’t want to know what those cost!
 
RC cartridge from Italy uses tempered lead in their premium competition line and their products have won pretty much everything you can win with a shotgun. But then so has Kent Gamebore with their relatively low antimony Diamond shot.


That’s kinda funny because Clever makes the same claim about some of their ammo, that it has won almost every competition worth winning.
If memory serves, Gamebore shot is quite a bit harder than the cheap Winchester and Remington ammo. I want to say 3.5% antimony but I could be wrong, it’s good ammo.
The thing is that for targets inside of about 25 or 30 yards, it really doesn’t matter what your throwing at a target, if it goes bang the target will break. The premium ammo doesn’t benefit much until you get out beyond that range but once you do then the extra performance is evident.
 
I use nickel plated shot for upland birds, and it does pattern better than unplated shot, but the biggest advantage is that it passes through feathers easier than unplated lead, and doesn't drag the feathers into the flesh. I have also used copper plated shot with similar results.
 
I am guessing that you would have to ask someone who sells "chilled shot", whether that is the same as "tempering" and whether what they sell is harder than plain lead shot - regardless what they call it. I believe that "hardness" is typically measured and reported using a Brinell scale - so a material with a lower Brinell number is usually softer than a higher Brinell number. I used to have a tool made by Lee Precision that would let me come up with a Brinell Hardness Number (BHN) for lead bullets that I was casting - I do not have that any more. You might find on various firearms and other things, little "dots" from when the hardness was checked at that spot. There is likely other additional scales that report similar - a numeric value that represents "hardness" of the material.

Google that, and see that pure lead typically has Brinell Hardness Number (BHN) of 5 - I found some alloys with tin and antinomy as high as BHN 28 - maybe they go higher than that? And I do not know what would be the "cut-off" to call something "hard" lead shot - is that BHN 7 or 22? - either would be "harder" than pure lead.

If you want to get into specifics, pure lead does not respond to heat treatment, or work hardening - as far as increasing yield strength. Adding metals in solid solution such as antimony will allow it to respond to heat treatment. However, the benefit is not linear, so there is a practical limit to how much antimony one can reasonably add. So, "chilled shot" must have some antimony, and likely refers to a minimal amount (1-2%). Magnum shot, and premium shot has larger amounts - around 5%. I'm guessing in the early days of shotgunning, un-alloyed soft lead was used. Some bright light figured out that additives such as antimony could be employed to enhance hardness, and "chilled shot" was born. Rather than employing air cooling in shot towers, liquid quenching was employed to give the desired heat treatment. Back in the day, chilled shot probably cost substantially more than soft lead shot.
I suspect the word "tempered" is a result of translation from Italian to English. It means heat treated. Imagine the translation of "chilled" into Italian on a box of shotgun shells.
 
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I decided to try a case of Remington Nitro-Steel and their Sportsman Steel shot shells. I was reading on some US forums and there was enough positive talk to warrant an investigation.

The Sportsman patterned as good as most inexpensive steel loads and upon opening up a shell for investigation there seemed to be decent consistency, again as you would expect.

The Nitro-Steel was a different story. The pellets are all pretty much perfectly round and are zinc coated. At close range there was little difference but out past 30 yards the patterns held a much better and tighter. They kill waterfowl extremely well at a reasonable price.

I don't imagine a zinc coating protects a vintage barrel in anyway but these shells are my go to these days for non-toxic.

Nothing to do with tempered lead shot so my apologies for the derail.
 
If they can make the lead hard with out the weight loss of antimony, nickel, copper it would be an advantage.
 
I’m a big believer in copper or Nickel plated shot for upland bird hunting as stubble jumper said, it makes for easier cleaning when your not trying to pull feathers out of shot holes in the meat.
I’ve even seen copper plated #6 hulls show up in the hull bin after an Annie Oakley shoot, can’t imagine who would ever do that!
 
I’m a big believer in copper or Nickel plated shot for upland bird hunting as stubble jumper said, it makes for easier cleaning when your not trying to pull feathers out of shot holes in the meat.
I’ve even seen copper plated #6 hulls show up in the hull bin after an Annie Oakley shoot, can’t imagine who would ever do that!

Surely not I...I'd be certain it wasn't labelled as such that's for sure! ;)
 
Are you saying that adding antimony to lead lightens it? Seems like minuscule amounts of 1 to 6% wouldn’t affect the overall weight too much.

Would certainly take a 6% advantage although it’s doubtful the difference would be that much. Premium handicap loads of 1250 fps 7.5s from the major manufacturers are impressive to say the least anyone that says otherwise is IMO is full of it.

The biggest factor would be price antimony is expensive so a harder pure lead cartridge from a good manufacturer like Clever couldn’t not be a win win if they kept the price down.
 
That’s an interesting article Spank, I’m Leary of what a lot of gun writers have to say but I think Roster has a high level of credibility in his work.
If nothing else the article defines hardness by SAAMI as well as what the manufacturers use which answers potashminers question. Unfortunately he doesn’t address “tempered” shot but I suspect we have a pretty good idea what that is.
 
Would certainly take a 6% advantage although it’s doubtful the difference would be that much. Premium handicap loads of 1250 fps 7.5s from the major manufacturers are impressive to say the least anyone that says otherwise is IMO is full of it.

The biggest factor would be price antimony is expensive so a harder pure lead cartridge from a good manufacturer like Clever couldn’t not be a win win if they kept the price down.

I most certainly agree that high antimony shot at 1250 fps is an advantage. My go to ammo for long range sporting clays targets is AA Supersport shells, 1 1/8 oz 7.5 with 5.5 antimony at 1300 fps. For close targets however, if it goes bang then the target breaks, no sense paying extra for your shell.

As far as pricing goes, I haven’t ever seen the Clever shells with tempered lead for sale so I don’t know where they stand in the cheap vs expensive or premium pricing. One thing I do know is that by not really knowing what the tempered lead catchphrase means I’d be a bit Leary of paying a premium price for them.
 
Yes but do you shoot the clever shells that have the so called tempered lead in them? Clever manufactures many types of competition shells and they’re Mirage shells are listed as 2.5 antimony, the ones I’ve seen listed as tempered are labeled T4 Pro Extra and T2 Compaq.
 
I mostly shoot T1 just because of the cost but I've used T2 and T3 a few times. The T2 Handicap works well on far targets. The T2 competition I buy only if the T1 is out of stock but it breaks clays just as well.
 
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