They're very cautious with providing pressures for these or any shot shells. I imagine it has something to do with potential liability. I did get some approximate numbers from Gamebore about 5 years ago. As I recall, they were quoting pressures in the 6500 psi range for the 12 ga Pure Gold shells and closer to 8500 psi for the 16 and 20 ga Traditional Game loads.
I bought flats of all 3 gauges and I use them only for hunting, so they're going to last me for years to come. Because of this, though, I haven't been in the market for these shells for several years, so I can't say definitively if anything has changed or not.
Assuming nothing has changed, the Gamebore Pure Gold shells were available only in 12 ga and were made in the UK by Gamebore. They were distributed in Canada by Kent Cartridge Co. So, I'm sure these are the same shells you refer to, probably still manufactured in the UK by Gamebore, but possibly repackaged in Kent boxes these days. As I recall, there were other loads made by Gamebore that weren't 2 1/2", nor low pressure, so you had to make sure you ordered the right ones. At the time, you could find the product code details on Gamebore's web site.
The 16 ga and 20 ga 2 1/2" low pressure loads were also made by Gamebore in the UK and sold through Kent in Canada. However, those gauges were sold under the "Traditional Game" trade mark, not the Pure Gold Label (at the time, they came in a mustard yellow box).
Visiting Gamebore's web site today, I see that they now have 12 ga Pure Gold paper shells. Reading the info they've published, I do not believe these are low pressure loads. The new Gamebore Pure Gold Super Game High Bird shells appear to be the current low pressure 12 ga load from Gamebore. Sadly, they don't come with paper shells, but I see that you now have to specify fiber wad or plastic cup. These "High Bird" Pure Gold shells are indicated as suitable for old English guns. The 16 and 20 ga "Traditional Game" loads are also listed as suitable for old english guns and do not appear to have changed since I purchased them.
What has obviously changed:
Now I see the same shells advertised on Kent's web site, too. On their site, the correct shells are listed under the "English" menu. (At kentgamebore.com)
There used to be only one shot size available for these low pressure shells in any gauge - English 6-shot (which is equivalent to 7-shot on the North American scale). I see that now there are shot size choices. Keep in mind that all the UK shot sizes equate to slightly smaller shot on the scale we're used to.
