re the GRT trigger (and similar after-market triggers).
It is a great trigger (I have one on my Gamo Delta), but the trigger weight is reduced significantly, and there is no way to adjust the trigger weight. Depending on how you shoot this may or may not be an issue for you. For me on a controlled range and me shooting, not a problem. But to use it as a trainer/beginners rifle for a kid or new shooter, IMHO the trigger is WAY TOO LIGHT. There is a safety factor with a heavy trigger. Similar reason your service pistol has a heavy trigger. For a field rifle, it depends on the circumstances of the hunt, where the trigger becomes too light. Keep the parts, and if it turns out to be too light, you can put the original trigger back in. Unfortunately, the only way to know is to actually install it and use it.
BTW have you thought about using a red-dot sight? Same zero magnification as iron, but a lot easier to see, especially if the background is dark.