doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Steel Shot through Improved Modified Choke

Hi Stanton,

I only have the wedge shaped pocket type choke gauge, no micrometer. Thanks for the reference to the Hallowell choke chart, that is really good information showing the choke size ranges.

I emailed AyA asking about their choke size and steel shot proof. So will see if they respond.

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TC

I found this vintage British shotgun for sale a while back. Made circa 1920/1925. From the proof marks, it shows that it was reproofed I believe in 2012. It has the CIP stamp and Standard stamp, So is this reproofed for use with standard steel shot then? The dealer selling the shotgun listed it as having Cylinder and Full chokes.



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TC

Yes Tim - the STD under the crown.
Very unlikely however that the barrels are 4140, but possibly 1040; which has similar tensile strength and hardness (but less corrosion resistance) and I would personally be apprehensive about using steel target loads through a .040" choke in those barrels.
Please let us know the actual bore and muzzle constriction.

Hi Drew,

I never purchased the gun, just saved the dealer's photo as I thought it was interesting. Could you even get 2 1/2 inch steel shot cartridges back in 2012 or even today in North America?

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TC

Tim, it's just a personal observation, so don't think I'm being insistent. But, find you a Skeet's bore micrometer (there are other brands, new and used). They're not prohibitively expensive, and will turn out to be one of the most useful "gun accessories" you would ever buy. I have the ability to measure bores and chokes on everything from .410 through 10 bore, and have never regretted the purchases.

Drew , the STD stands for Standard Nitro Proof rather than Standard Steel. As this chart from the current Eley Shooters Diary shows it is just the normal Nitro Proof level (for lead cartridges).

Superior Proof is again for lead cartridges but higher pressures.

The Steel shot mark is the CIP Fleur de Lys Steel shot mark.

In the UK standard steel shot cartridges are supposed to be usable (subject to maximum shot sizes and minimum choke sizes ) in guns Proofed for Standard Nitro.

Guns Proofed with the Fleur de Lys mark should be OK with steel loaded to CIP Pressures.

BUT I understand many American steel cartridges are loaded to higher pressures allowed by SAAMI but in excess of CIP limits.

Tim: I did some looking and couldn't find 2 1/2" steel loads offered today

Thank you Parabola
Are you saying that British Standard Proof is NOT for steel?

This is from the CIP site

12g 50mm, 60mm, 65mm, and 70mm “Standard Proof” lead or steel (limited to no larger than 3.25 mm / U.S. No. 4s and max. fps 1,300)
(Numbers are transducer BAR converted to PSI)
Maximum Average (SERVICE) Pressure 740 BAR = 10,733 psi; SAAMI is 11,500 psi
Maximum Statistical Individual Pressure 850 BAR = 12,328 psi
Mean PROOF Pressure 930 BAR = 13,489 psi

BTW: CIP allows much higher pressures for 3" loads than does SAAMI. 12g 3" is 11,500 psi and 3 1/2" is 14,000 psi
12g 3” & 3 1/2” “High performance/Superior Proof”
Maximum Average (Service) Pressure 1050 BAR = 15,229 psi
Maximum statistical individual pressure 1200 BAR = 17,405 psi
Magnum proof 1320 BAR = 19,145 psi

High Performance Steel regulations: the barrels should carry the High Performance Steel Fleur de Lys stamp and be marked “Steel Shot”

More
https://www.gwct.org.uk/media/1094678/GTA_factsheet_shootingnonlead_ver102.pdf
"‘Standard steel’ cartridges have been designed by manufacturers in association with proof authorities that can be fired through any nitro-proved gun."
"Increased velocity can also be achieved by changing the propellant and generating more pressure. Such cartridges are known as ‘high performance’ steel. They should only be fired in guns proved for steel. This is indicated by a ‘fleur-de-lis’ mark on the gun and the words STEEL SHOT."

I recently finished up a Merkel 147E 12 bore. Owner shoots steel through it exclusively. Not the crazy fast stuff either, “mild steel load”. He was very surprised when I told him his gun was off the face and then proceeded to push feeler gauge after feeler gauge through the gap. Merkels are tough guns. They use great steel, have ample locking surfaces. Steel loads are just harsh. Your AyA will come off the face fairly quickly with the use of steel loads. They simply aren’t as strong as a Merkel, nor are they fitted up as precisely as a Merkel.

Is your AyA made up as a wild fowling piece or a game gun? Heavy action? Thick barrels?

The recoil on most steel loads (even mild ones) is pretty significant. Hopefully your stock will be able to also take the heavy repeated jolts a steel load provides. Keep an eye on that too.

I shot my BSS off face on the right barrel with years of steel loads, not hyper-velocity stuff, either.

I can't see how the composition of the payload can be any harsher on the jointing on a break action gun, Dustin. It must be just the combination of heavier (1 1/4 oz. and up) and higher velocities that does it? I can't imagine the fact that the shot is steel, as opposed to lead, playing a part in a gun coming off face. Am I missing something?

Recoil isn't shot type dependent. It's just payload and velocity. Higher pressures, would do it, however, and perhaps the steel load pressures are higher. That would not surprise me.

Personally, I just use bismuth now, but there was a time when I shot steel.