Steel Shot

[reggiegun]

What steel shot, if any can I put through my 3/4 and Full choked shot gun for ducks?

 

Reggiegun

[GingerCat]

Not much if any according to cip guidelines, someone will be along shortly to point out the facts.

[figgy]

None safely as its know to bulge the barrels at the choke as it won't crush like lead and something's got to give.

 

Use bismuth or other soft non toxic shells safe for your gun.

 

Figgy

[wymberley]

None safely as its know to bulge the barrels at the choke as it won't crush like lead and something's got to give.

 

Use bismuth or other soft non toxic shells safe for your gun.

 

Figgy

Although the initial reason for the the bulge - termed a 'ring bulge' because it goes all around the barrel and looks just like a ring on a finger - is an obstruction - the choke - it is not the steel shot which will not compact that causes it but the fact that immediately before the 'restriction' the load and the gases behind it were travelling at the same speed. Once the speed of the load was momentarily checked by the choke, the gases still travelling at their original speed tried to overtake and piled up immediately behind the load/wad. It is this pressure that caused the bulge which occurs a short distance towards the muzzle from the point at which the restriction was initially encountered.

 

The above I'm sure of. If I were to have a fixed choke gun reamed out to permit the use of steel shot, because I'm not so sure on this bit, I'd be inclined to seek qualified advice regarding the advantage that, now the parallel portion of the choke has been extended, then so too should the cone portion thus reducing its angle and thereby also reducing the possibility of the occurence of any bulge. In other words, getting your local RFD/'gunsmith' to simply whack a reamer through may not be ideal.

 

(I think I'm sure!)

 

Edit: Missing word added.

Edited November 14, 2013 by wymberley

[mudpatten]

Your best bet is to go to the BASC website and have a good read about steel shot.

 

There is a great deal of misunderstanding about steel shot, shot size and choke.

[langlands]

Ok, as I understand it the bulge is caused by the continuous, momentary, lengthening of the barrel at its thinnest section. This being due to the charge hitting a partial obstruction (the choke) and applying an axial (?) load which eventually results in a bulge. I read about this from a guy who was shooting an aftermarket extended choke and monitored the changes to diameter and length.

 

As I remember, the diameter increased very little, but the length increased considerably (in thousands of an inch) as shooting progressed.

 

So, extending the choke area outside of the barrel does allow greater control of the 'radial worked' area of the constriction, but the force applied to the length of the tube is still the same and consequently will result in changes to the thinnest section of the barrel

 

I think this occurred in a barrel with the older type of choke tube with thin walls.

 

I will no doubt, be corrected by a 80 year old gamekeeper, who has shot steel for 70 years, is a part time consultant for the CIP authority and has a MSc in metallurgy.

 

As I say, this is as I understand it; I would welcome any other ideas on 'rings'

 

[wymberley]

Ok, as I understand it the bulge is caused by the continuous, momentary, lengthening of the barrel at its thinnest section. This being due to the charge hitting a partial obstruction (the choke) and applying an axial (?) load which eventually results in a bulge. I read about this from a guy who was shooting an aftermarket extended choke and monitored the changes to diameter and length.

 

As I remember, the diameter increased very little, but the length increased considerably (in thousands of an inch) as shooting progressed.

 

So, extending the choke area outside of the barrel does allow greater control of the 'radial worked' area of the constriction, but the force applied to the length of the tube is still the same and consequently will result in changes to the thinnest section of the barrel

 

I think this occurred in a barrel with the older type of choke tube with thin walls.

 

I will no doubt, be corrected by a 80 year old gamekeeper, who has shot steel for 70 years, is a part time consultant for the CIP authority and has a MSc in metallurgy.

 

As I say, this is as I understand it; I would welcome any other ideas on 'rings'

I don't know whether it will help but you could have a shufti at Volume 111 of The Modern Shotgun by Burrard - not just because of what he writes but also because of other reading as he always acknowledges the authorities from whom his information is gleaned when appropriate. As said, it may not help because like the OP he refers - pretty obviously in 1932 - to fixed choke barrels. The forces on multi choked barrels may well be entirely different. I would just query the validity of your reference though as the charge, now in a gaseous form, is not hitting a partial obstruction but a total one in the form of the wad and as it acts equally in all directions this explains the ring bulge.

 

Edit: PS Found it, the info is in Chapter XV11 hidden amongst the "Bursts Caused By Obstructions In The Bore".

Edited November 14, 2013 by wymberley

[Dangerous Brian]

Eley say on their website the original VIP steel comforms to the CIP specification (1300fps). Have a search for CIP steel regulations on the internet or have a look at the steel No. 5 thread for guidance on chokes with various shot sizes. Having said that, full choke with steel might be pushing it solely on the pattern produced.

 

As regards choking vs barrel damage at the chokes I am only going on what I have read. Some say any choke is fine up to a certain shot size, within the CIP speed limit, others say don't go tighter than half for any steel. Where damage has been stated I don't remember ever reading what velocity/ momentum the shell was that caused it. No doubt someone else will be along to fill in the blanks.

 

Sorry I can't be more precise but I hope it's a start for you.

[wymberley]

Ok, as I understand it the bulge is caused by the continuous, momentary, lengthening of the barrel at its thinnest section. This being due to the charge hitting a partial obstruction (the choke) and applying an axial (?) load which eventually results in a bulge. I read about this from a guy who was shooting an aftermarket extended choke and monitored the changes to diameter and length.

 

 

Surely if the cause was as you describe and not a result of forces applied by the charge pressure, then the lengthening of the barrel at its thinnest section would have resulted in even more thinning and therefore a 'ring depression'.