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Another steel question.


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Unfortunately, the answer can't really be short. Muzzle velocity and downrange energy will be very different ...

 

According to Gamebore's website, they have the following :

 

White Gold, lead : 1450 fps. 28g, 7.5 or 8 shot

White Gold, steel : 1350 fps, 24 or 28g, 7.5 or 9 shot

 

For 20 bore, however :

20g Competition (lead) : 1350 fps, 21, 24 or 28g, 7.5, 8 or 9 shot (a few variants, all show the same speed)

20g 'steel competition' : 1350 fps, 24g, 7 shot

 

So for 12 bore, they show steel being slower. For 20 bore, identical.

However, all those are muzzle velocity ...

 

 

The real difference will be shown downrange. Steel (being less dense) will lose velocity faster, as each pellet will be carrying far less energy than the equivalent lead pellet.

 

As an (extreme) example. Imagine a ball of metal, 1cm across. That has a volume of 0.52 cm3.

If made of lead, that ball will have a mass of (11.342*0.52) = 5.89 grams (90.9 grains) (density of lead is 11.342g/cm3)

If made of steel, that ball will have a mass of (7.6*0.52) = 3.95 grams (61 grains) (density of steel is roughly 7.6g/cm3)

 

If those 2 balls are then fired at 1350 fps, the energy in each will be as below ...

 

(remember, energy in ft/lbs = (mass times velocity squared) divided by 450240

Lead : (90.9*1350*1350)/450240 = 368 ft/lbs

Steel : (61*1350*1350)/450240 = 247 ft/lbs.

 

 

TL;DR

 

For a pellet of the same volume, at the same velocity, the lead pellet carries nearly 50% more energy. It has, per unit of weight, far less air resistance, so will maintain that energy further downrange.

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There are some good videos on you tube of your average joe testing a good range of carts at different distances and showing the patterns.

 

Surprising is when you get up to the higher speed steel it blows it's pattern, around the 1400 fps mark they seem to pattern best.

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  • 4 weeks later...

Steel accelerates quicker but slows quicker too so depends.

 

On the marsh anything close gets next to no forward allowance and anything at distance I shoot the same as I would a clay at the same range. Works for me.

Figgy , how does steel shot accelerate faster than lead ?

I am not saying it doesn't , just can't figure in my little head comparing an ounce of lead vs an ounce of steel .

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Figgy , how does steel shot accelerate faster than lead ?

I am not saying it doesn't , just can't figure in my little head comparing an ounce of lead vs an ounce of steel .

Steel loads are lighter for the same volume, so will accelerate faster if the same amount of powder is used, but because of the higher pressures, due I presume to steel not deforming, powder weights might be lower for steel, never loaded any steel so not sure.

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Steel loads are lighter for the same volume, so will accelerate faster if the same amount of powder is used, but because of the higher pressures, due I presume to steel not deforming, powder weights might be lower for steel, never loaded any steel so not sure.

 

Hmm. That doesn't seem logical.

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Steel loads are lighter for the same volume, so will accelerate faster if the same amount of powder is used, but because of the higher pressures, due I presume to steel not deforming, powder weights might be lower for steel, never loaded any steel so not sure.

Its loaded by weight though not volume so 1oz of steel at 1400 fps I would imagine accelerate at the same speed as 1oz of lead ,I suppose different powders may give a very slight difference but thats about it.

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Its loaded by weight though not volume so 1oz of steel at 1400 fps I would imagine accelerate at the same speed as 1oz of lead ,I suppose different powders may give a very slight difference but thats about it.

 

I never thought I'd say this, but I agree with fenboy.

 

Since F = ma​, if the force and the mass are the same, then so will the acceleration be.

 

The confusion was in the wording of the question and the first response I think. Steel no more accelerates of itself than any other substance. However it can be made to accelerate with the application of a force, which is provided by the powder / expansion of combustion gases.

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If you put the same force behind an ounce of steel pellets or an ounce of lead pellets the acceleration will be the same.

 

 

But, as we know, steel loses energy quicker than lead and consequently manufacturers normally go up a couple of sizes to cover this aspect.

 

 

Manufacturers often load a larger load of steel to compensate and so we are then not comparing equal actions.

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Since writing the above, it occurs to me that steel could accelerate ever-so-slightly more quickly than lead, since the greater compressibility of lead will absorb some greater and definite (but still tiny) proportion of the energy of combustion, reducing the magnitude of the propulsive force and therefore the acceleration.

 

By the time you're at this level though, I doubt there would be any practical difference. We could carry on looking at the physical properties of the shot and ask whether a wad filled with lead fills the bore more tightly - because of the deformation effect - and therefore regains (or exceeds) the acceleration lost through energy loss in deformation.

 

Reductio ad absurdam, etc.

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Since writing the above, it occurs to me that steel could accelerate ever-so-slightly more quickly than lead, since the greater compressibility of lead will absorb some greater and definite (but still tiny) proportion of the energy of combustion, reducing the magnitude of the propulsive force and therefore the acceleration.

 

By the time you're at this level though, I doubt there would be any practical difference. We could carry on looking at the physical properties of the shot and ask whether a wad filled with lead fills the bore more tightly - because of the deformation effect - and therefore regains (or exceeds) the acceleration lost through energy loss in deformation.

 

Reductio ad absurdam, etc.

I seem to recollect Ian Charlton telling me that compressing the lead shot on ignition used something like 20 % of the total energy involved.

Which is one good reason that steel shot creates higher pressures ..

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Surely what matters is the muzzle velocity, muzzle energy and downrange energy and velocity. These 4 things should give you everything you need for deciding on what steel loads to use (along with a few pattern tests). The acceleration thing has no effect once the muzzle velocity is considered because positive (forward) acceleration stops once the shot leaves the barrel. It may matter to barrel pressures but so what as long as the load is rated as safe for your gun? Deformation which may or may not happen with lead depending on the powder load and choke equally seems a red herring when considering external ballistics over the ranges normally shot at, where once again, it is muzzle energy/velocity figures that matter (and those downrange) along with the pattern thrown . If some energy is expended in propelling lead to 1400fps, it doesn't affect the comparison with steel at 1400fps as you are still comparing what happens between the two loads being compared, hence the size and pattern of the shot becomes a more important consideration for maintaining effective downrange performance. Or...am I missing something here?

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Surely what matters is the muzzle velocity, muzzle energy and downrange energy and velocity. These 4 things should give you everything you need for deciding on what steel loads to use (along with a few pattern tests). The acceleration thing has no effect once the muzzle velocity is considered because positive (forward) acceleration stops once the shot leaves the barrel. It may matter to barrel pressures but so what as long as the load is rated as safe for your gun? Deformation which may or may not happen with lead depending on the powder load and choke equally seems a red herring when considering external ballistics over the ranges normally shot at, where once again, it is muzzle energy/velocity figures that matter (and those downrange) along with the pattern thrown . If some energy is expended in propelling lead to 1400fps, it doesn't affect the comparison with steel at 1400fps as you are still comparing what happens between the two loads being compared, hence the size and pattern of the shot becomes a more important consideration for maintaining effective downrange performance. Or...am I missing something here?

I think you are right.
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