Longshot, you are darn near the most frustrating poster on TS.com. The fact that the shotspeed rule is 1200 fps according to ANSI/SAAMI definitions - and therefore allows a maximum of 1290 fps, has been explained to you, in detail and with documentation at least ten times, as well as the FACT that never, ever, not once has the ATA rule read 1200 fps. When are you going to quit claiming otherwise? When are you going to listen?
But still, your question, if you had asked it correctly, "When did the ATA accept SAAMI standards for shot speed?" can't be answered. It's not in any minutes of the meetings of the BOD. There is a sidelong reference naming a participant (not me!) but otherwise, nothing.
When Phil Kiner proposed a lower number at a recent BOD meeting and I advised the Delegates not to do it, I asked the person who made the original SAAMI motion (by my and an Iowa Delegate's memory) and he didn't remember it all. So you question can't be answered. I don't remember what year and the guy we think did can't even remember doing it. So, sadly, you came up dry on this one.
So why did I advise the BOD not to vote for Mr. Kiner's proposal?
Several reasons. Speed is not a problem now (see reference later). That's the best answer for not doing anything I know of.
The ATA is not capable of enforcing a speed rule because they are not capable of measuring shot speed. Believe me.
But the biggest reason is that the whole thing about raising the shot-speeds and all that is just a bunch of hooey promoted by people who simply don't know what they are talking about.
The first Handicap Shells I was aware of showed up at the Spring Grand in about (correction here from 1992) 1990. I've still got a box or two and I just tested a couple and they (after correction) are about 1275 fps, measured by SAAMI-like equipment which had been calibrated second-hand and only first-hand really counts. But they were killers in the recoil department and were soon toned down.
There were plenty of 3-dram-labeled shells which were well over 1200 fps and right in the sweet-spot for handicap shells being sold today.
So the higher scores being shot today are _not_ caused by "handicap speed" shells which we'd never seen before. We were shooting them all along, but didn't know it. Top long-yardage handicap shooters are firing today shells about like they did 25 years ago. So that's not the cause of the higher scores they are shooting today. The big difference is that today there are so many more of them.
Neil