Similar experience here, even switching to the Sig R5. I now have a lonely TRS-25 sitting on my bench.I must be the lucky one. I had one mounted to an Ultimak on my SLR-107FR for around 1500 rounds. It never failed to work and it never lost zero. I have since replaced it with a Sig Romeo 5. Because of the shake awake technology. I hope the Sig holds up as good as it did. It now sits on my CZ scorpion Evo three.