Quote:
Originally Posted by Bruce Day
Frank, your statement "loaded to SAAMI standards", what pressures are you talking about ?
The present 12 ga 2 3/4" standard is 13,000 psi maximum, up from the previous of 10,500, presumably to cycle gas operated autos. Combine that with a SAAMI allowable two coefficients of error of 7 1/2 percent each, and a SAAMI allowable load in excess of Parker proof loads could result, and certainly in excess of Parker maximum operational loads.
The old STS 1 1/8 3 dre loads used to run about 9500 if I remember correctly. Are these different?
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Bruce, we all know that RST shells are loaded to comparatively low pressures and despite that the company is being responsible with a WARNING similar to the one I cited from the Remington shell box flap. I've shot RST's for years and was aware of that. Good for RST!
Now let’s consider some historical data: in 1904 an accepted industry service pressure for 12-gauge was 3 to 3-1/2 tons per square inch “in warmer months”. Lead crushers were in use at that time. Modern transducer technology would add about 10% to that pressure, thus the max service pressure was about 7700 psi.
Progressive powders were introduced in 1922 and a 1929 reference shows the max service pressure was held to 5.0 tons per lead crusher = about 11,000 psi transducer.
That ceiling has carried over pretty much intact over the years. In 2006 the SAAMI max service pressure (transducer) was shown as 11,500 psi for 12-gauge, 2-3/4”. And as recently as 2015 it was still 11,500 with 12,800 max psi as a sample mean. The acceptable lot to lot mean was a bit lower than that.
Bruce, I am interested in hearing more about your statement citing a move from 10,500 (?) to a present 13,000 psi maximum + two 7.5% standard errors = about 15,000 psi. Where did that info come from? My references show the current SAAMI spec is dated 2015 and still shows 11,500 psi for service pressure.
Nevertherless, the majority of vintage double guns were made over the years prior to the late 1920’s and while many are in excellent condition, others were given a modicum of care and are pretty sad. Also, some composite barrels can be suspect due to corrosion and hidden welding flaws. Who would responsibly give a blanket OK to shoot modern shotshells in any and all of them, shells that could be close to or at the absolute max industry pressure? Thus the Warnings on shell boxes whether those with high velocity/pressure shells, or not. I’m quite sure most vintage double gun shooters know this.
Back to Remington’s new C&F shotshells, without knowing their average and max mean pressures from lot to lot, I say again it’s prudent to consider they could be loaded to max pressure and urge gents again to heed the important safety WARNING that’s on the box. That's what I had written. I have not seen a C&F shell box but I’d be surprised if it doesn’t have the standard/responsible Remington shotshell Warning similar to what I'd copied here earlier.
All of this reminds me of the tale about the dumb farmer who hit his mule on the side of the head every morning with a piece of pipe, just to show who was boss. The mule winced every time but silently endured the torture for years. Then one morning the farmer hit the mule and the animal kicked him in the groin and broke his pelvis. Afterwards the farmer said “Gee, he never did that before”.
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