Hi, Sandy! Actually, the GP11 isn't match. Swiss match cartridges only came out last year and they're boxer. The maker is RUAG, the people who own the original factory.
The GP11 is the issue cartridge that began in 1911 and has been used in the 1911sr, the k11, the k31, the zfk3155 and the PE57. All of them use the GP11.
The only match brass for the 7.5 Swiss is from RUAG itself, and it is available as both brass and loaded cartridges, but so is the new brass from Grafs and Dad says his runout on that brass last summer shows that its every bit as good as RUAG. We have many thousands of Norma and RUAG brass and cases of GP11, but we only shoot the GP11 in the PE57s cuz our own loads shoot better in the SRs, the k31s and the zfk3155s.
But, guess what. We seldom shoot the PE57s or AMTs cuz its MUCH more fun to shoot the other Swiss rifles. I love my 1911sr.
:^)