Steel shot and forcing cones?

[Heym SR20]

Think i will agree to disagree with you until the pressure at the muzzle with steel shot are scientifically made available.

As general consensus is steel shot going through the chokes does not yield like lead shot, otherwise the patterns would not be as tight as they are reported to be due to the damage to the shot.

Hence the recommendation on not using chokes tighter than half and using steel shot approved chokes.

As the pressure can spike as steel shot passes through the choke the pressures you quoted are with lead shot, not steel.

Take a shot cup full of steel shot. You can easily squeeze it with minimal pressure from your fingers. Try it if you don’t believe. Shot acts like a fluid, especially hard shot which doesn’t deform.

Ever since they started making lead shot the emphasis has been on making it harder through quenching and adding other metals, notably tin and antimony to the mix, or adding coatings such as copper.

 

[billgatese30]

There are lots of lead cartridges with (claimed) MV of 1450-1575fps
It’s one of the biggest marketing pushes around…
Faster cartridges

Peak pressure is at the chamber and dramatically reduced at the muzzle
Winchester and Greener did this study back in the 60s
W-W lab data on three different 12 ga factory loads:
700 psi @ 26"
620 psi @ 28"
605 psi @ 29"

Your barrels above didn’t bulge due to cartridge pressure IMO
That is a classic muzzle blockage bulge, was, mud, snow etc

The reason your shotgun needs steel proofing is the chamber pressure

I am not sold on the “can’t shoot steel through 3/4 chokes”
Especially standard steel cartridges
All steel is enclosed in a cup or tube of some description
All cups are much much thicker than the corresponding constriction at the muzzle
4 thou is all there is between 1/2 & 3/4
Cups are more like 50 thou of a soft plastic or bio wad construction

The theory about less maleable steel (which is technically IRON) not deforming as it goes through the chokes like lead can….is largely that. Theory
The wad/cup allows significantly more compression

Most lead fibre cartridges are wads not cups
Lead is in direct contact with barrels
No steel cartridges allow this

Depending on where you reference choke constriction, 1/2 - 3/4 can either be .004 or .010 thou. Either way I would love to see some proper testing to show what happens with chokes >1/2 in real world testing as I would love you to be correct about tighter than 1/2 being ok for standard steel!

 

[Tralle]

Just wondering if it's important.

I doubt I will ever be satisfied with leaving plastic pollution around...

My local guy doesn't stock eley and no one seems to know what the residue from their wads is.
All that said. I would like to know what if any is the roll of the forcing cone with steel shot???

Jocker wads is the way forward on the plastic part.

After using Kent fasteel biowads for a season my brand new benelli has pitting just in front of the chamber.
None of my other guns has this after years of (ab)use.
I cant prove that there is causation, by it is the only gun i have used biowads extensively in.

 

[Smellydog]

Jocker wads is the way forward on the plastic part.

After using Kent fasteel biowads for a season my brand new benelli has pitting just in front of the chamber.
None of my other guns has this after years of (ab)use.
I cant prove that there is causation, by it is the only gun i have used biowads extensively in.

Thank you.

 

[bobo]

Your barrels above didn’t bulge due to cartridge pressure IMO
That is a classic muzzle blockage bulge, was, mud, snow etc

The picture is from the Danish Technological Institute and was taken in connection with testing chokes in thin-walled shotguns with larger shot. I therefore have no doubt that the dent is caused by steel shot.
It is not the pressure that forms the dent. It is formed because large steel shot comes at a very high speed and cannot "pack" itself. If you reduce the speed by 30-50m/s there should be no problems.

Back in the late 80s when lead shot was banned the first local places in this country we had exactly the same discussions as in the UK, and Germany right now.
Practical experience over the last 30 years, where lead has been completely banned, shows very little damage to shotguns caused by steel shot.
One of the few things that can do damage is large high velocity 3.5mm+ steel shot in tight chokes that are weak and not designed for them.

British "standard performance" steel shot is not legal in Denmark.
The law for hunting states that the minimum velocity for shot with a density below 9/gram-cm2 must be greater than 400 m/s measured 1.5 meters from the muzzle.
"standard performance" just can't meet this requirement they normally need 5-10 m/s, so we have to use at least what CIP calls "high performance".
But "extreme performance (450m/s+)" and "hyper performance(470m/s+)" are also used most in this country.
I doubt that our "hyper cartridges" can comply with CIP, but that doesn't matter here since we're not part of CiP.

Old-fashioned plastic wads are on the last go in this country. Virtually everything now is biowads, and we expect "bio" to be mandated by law in the near future.

 

[Liveonce]

Take a shot cup full of steel shot. You can easily squeeze it with minimal pressure from your fingers. Try it if you don’t believe. Shot acts like a fluid, especially hard shot which doesn’t deform.

Ever since they started making lead shot the emphasis has been on making it harder through quenching and adding other metals, notably tin and antimony to the mix, or adding coatings such as copper.

Then why do the proof house recommend no choke tighter than a half for steel shot?

a few percentage of antinomy will never make lead shot as hard as steel shot, and no tin is added to lead shot alloy,
it contains lead, antinomy and a tiny amount of arsenic. No tin.

 

[Tralle]

The picture is from the Danish Technological Institute and was taken in connection with testing chokes in thin-walled shotguns with larger shot. I therefore have no doubt that the dent is caused by steel shot.
It is not the pressure that forms the dent. It is formed because large steel shot comes at a very high speed and cannot "pack" itself. If you reduce the speed by 30-50m/s there should be no problems.

Back in the late 80s when lead shot was banned the first local places in this country we had exactly the same discussions as in the UK, and Germany right now.
Practical experience over the last 30 years, where lead has been completely banned, shows very little damage to shotguns caused by steel shot.
One of the few things that can do damage is large high velocity 3.5mm+ steel shot in tight chokes that are weak and not designed for them.

British "standard performance" steel shot is not legal in Denmark.
The law for hunting states that the minimum velocity for shot with a density below 9/gram-cm2 must be greater than 400 m/s measured 1.5 meters from the muzzle.
"standard performance" just can't meet this requirement they normally need 5-10 m/s, so we have to use at least what CIP calls "high performance".
But "extreme performance (450m/s+)" and "hyper performance(470m/s+)" are also used most in this country.
I doubt that our "hyper cartridges" can comply with CIP, but that doesn't matter here since we're not part of CiP.

Old-fashioned plastic wads are on the last go in this country. Virtually everything now is biowads, and we expect "bio" to be mandated by law in the near future.

I must admit I haven't found the hyper performance loads to offer much over the "standard" high performance loads other than noise and recoil.

I have grown up using steel, so I may have a different "mindset" regarding at what distances you shoot.

 

[Heym SR20]

Then why do the proof house recommend no choke tighter than a half for steel shot?

a few percentage of antinomy will never make lead shot as hard as steel shot, and no tin is added to lead shot alloy,
it contains lead, antinomy and a tiny amount of arsenic. No tin.

Why do they recommend no tighter than 1/2 choke.

Well plenty of tests have shown that vast majority of guns can perfectly accept steel shot no matter what the choke.

Secondly, you really don’t need choke with steel shot to get a perfectly good pattern to kill game and clays.

But the Proof House is ultra conservative and err very much on the side of caution. That is the whole point of proof - you test the guns with stand force’s well beyond what they will be using every day.

Many older guns of cheap production were made with full choke. Many of these are probably not in best of condition. Fine game guns were only ever made with improved cylinder and 1/4 choke or 1/4 and a 1/2. I suspect the recommendation of no more than 1/2 choke is to encourage all those with old guns of very unsure serviceability to actually take them to a gunsmith for a check over before having chokes opened up.

It might even be a ruse whereby some might actually go and upgrade the old rattly cheap Belgian made keepers gun that is 100 years old to something like a kofs or similar.

It’s probably also why the suggest the gun should have proofed sometime in the last 72 years ie post 1954.

 

[Liveonce]

Why do they recommend no tighter than 1/2 choke.

Well plenty of tests have shown that vast majority of guns can perfectly accept steel shot no matter what the choke.

Secondly, you really don’t need choke with steel shot to get a perfectly good pattern to kill game and clays.

But the Proof House is ultra conservative and err very much on the side of caution. That is the whole point of proof - you test the guns with stand force’s well beyond what they will be using every day.

Many older guns of cheap production were made with full choke. Many of these are probably not in best of condition. Fine game guns were only ever made with improved cylinder and 1/4 choke or 1/4 and a 1/2. I suspect the recommendation of no more than 1/2 choke is to encourage all those with old guns of very unsure serviceability to actually take them to a gunsmith for a check over before having chokes opened up.

It might even be a ruse whereby some might actually go and upgrade the old rattly cheap Belgian made keepers gun that is 100 years old to something like a kofs or similar.

It’s probably also why the suggest the gun should have proofed sometime in the last 72 years ie post 1954.

yet no such issues with lead shot, no need to limit the choke size, no need to warn owners, but rather let the owner decide which choke to use for the purpose in hand, Funny that is it not.

Steel shot is only being used because it’s the only alternative shot that is affordable to that of lead, you can choose to ignore that it has issues and limitations if you like.

 

[timbrayford]

I must admit I haven't found the hyper performance loads to offer much over the "standard" high performance loads other than noise and recoil.

I have grown up using steel, so I may have a different "mindset" regarding at what distances you shoot.

What shotgun do you use?

 

[timbrayford]

yet no such issues with lead shot, no need to limit the choke size, no need to warn owners, but rather let the owner decide which choke to use for the purpose in hand, Funny that is it not.

Steel shot is only being used because it’s the only alternative shot that is affordable to that of lead, you can choose to ignore that it has issues and limitations if you like.

Absolutely, if cost/availablity wasn't an issue bismuth would be replacing lead shot.

 

[enfieldspares]

Depending on where you reference choke constriction, 1/2 - 3/4 can either be .004 or .010 thou. Either way I would love to see some proper testing to show what happens with chokes >1/2 in real world testing as I would love you to be correct about tighter than 1/2 being ok for standard steel!

In the USA as I once read the opposite happens. That is the more open the choke the more (with steel) the tight the pattern. The tighter the choke the more (with steel) open the pattern. Supposedly the steel shot payload squeezes in its plastic cup like others say and then as it cannot like a lead payload compress to do this bursts apart once free of the choke. As the squeezing maybe has imparted lateral force that releases itself sideways once past the choke? I suppose a crude analogy would be football fans exiting the ground at the end of the match? They all squeeze together to go through the exit doors then once out of those on the concourse spread out far and wide?

 

[enfieldspares]

Absolutely, if cost/availablity wasn't an issue bismuth would be replacing lead shot.

Yes. I first tried bismuth after the duck lead ban. If it had been the same price as lead I would have used it for all game shooting as it patterns better. Or I found it to in my gun I was then using.

 

[Heym SR20]

yet no such issues with lead shot, no need to limit the choke size, no need to warn owners, but rather let the owner decide which choke to use for the purpose in hand, Funny that is it not.

Steel shot is only being used because it’s the only alternative shot that is affordable to that of lead, you can choose to ignore that it has issues and limitations if you like.

Plenty if such issues with lead shot. Take a heavily loaded 2 3/4” or 3” cartridge and put it into an old lightly built 2 1/2” chambered game gun. Chances are it will let go - perhaps not on the first shot, but you will stretch the action etc.

And remember that chamber length relates to length of the fully open cartridge, not the closed length, so it is perfectly possible to jam a 3” or a 2 3/4” cartridge into a 2 1/2” chambered gun.

When you pull the trigger the mouth of the cartridge will be in the forcing cone so cannot open fully, which will raise the pressures even further.

It’s one of the reasons why most modern guns are 3” chambered. It’s to make them idiot proof.

 

[Liveonce]

Plenty if such issues with lead shot. Take a heavily loaded 2 3/4” or 3” cartridge and put it into an old lightly built 2 1/2” chambered game gun. Chances are it will let go - perhaps not on the first shot, but you will stretch the action etc.

And remember that chamber length relates to length of the fully open cartridge, not the closed length, so it is perfectly possible to jam a 3” or a 2 3/4” cartridge into a 2 1/2” chambered gun.

When you pull the trigger the mouth of the cartridge will be in the forcing cone so cannot open fully, which will raise the pressures even further.

It’s one of the reasons why most modern guns are 3” chambered. It’s to make them idiot proof.

you don’t give up do you why would anybody put any 2.3/4” or 3” cartridge in a 2 1/2” chamber gun when the gun is not designed for that length of cartridge? Prey tell how often you read of such happing?
However it matters not what lead shot 2.1/2” cartridge they put in with any choke or any size shot.

Let’s see what happens when somebody get hurt by a gun not designed to use steel shot in it, a good legal team suing for damages will state incorrect ammunition was being used, as was the case in the USA several years back when a person suing the user of a rifle for using 7.62mm nato ammo in a gun designed for .308 Winchester. The gun manufacturer as an expert witness stated that the gun was not designed for 7.62

Define modern gun? apart from semi auto and now the need to future proof them for steel shot most guns especially clay guns are 2.3/4” chamber. Semi autos tend to be 3” as they are used a lot by wildfowlers.

 

[timbrayford]

Plenty if such issues with lead shot. Take a heavily loaded 2 3/4” or 3” cartridge and put it into an old lightly built 2 1/2” chambered game gun. Chances are it will let go - perhaps not on the first shot, but you will stretch the action etc.

And remember that chamber length relates to length of the fully open cartridge, not the closed length, so it is perfectly possible to jam a 3” or a 2 3/4” cartridge into a 2 1/2” chambered gun.

When you pull the trigger the mouth of the cartridge will be in the forcing cone so cannot open fully, which will raise the pressures even further.

It’s one of the reasons why most modern guns are 3” chambered. It’s to make them idiot proof.

Speaking from experience I've fired 1000s of lead shot cartridges over a 50+ year period in shotguns with non magnum 3" chambers and proof and had no problem with any of them. I'm not wealthy enough to take a chance on steel shot trashing any of my guns!

 

[BigT]

you don’t give up do you why would anybody put any 2.3/4” or 3” cartridge in a 2 1/2” chamber gun when the gun is not designed for that length of cartridge? Prey tell how often you read of such happing?
However it matters not what lead shot 2.1/2” cartridge they put in with any choke or any size shot.

Not just read about it ,seen it. Because “it will be fine , it fits.”

 

[Liveonce]

Not just read about it ,seen it. Because “it will be fine , it fits.”

Then with that level of IQ they should never have a gun licence to start with, warnings are on every carton of cartridge regarding chamber length.

 

[enfieldspares]

Why would anybody put any 2.3/4” or 3” cartridge in a 2 1/2” chamber gun when the gun is not designed for that length of cartridge? Prey tell how often you read of such happing?

It happens more often that is thought.

 

[Tralle]

What shotgun do you use?

A the moment a Benelli semi, but have been shooting Valmets and Berettas as well