Just more feedback for you :)
Your models are very nice, however sometimes the scope/ironsight isn't so good with the gun it is for, for example, SMG has a lot of recoil when firing, so using like a line on the end of the sight isn't the best, as it's harder to guide your aim onto it when firing with such recoil.
An example below --
http://img192.imageshack.us/img192/9823 ... black4.pngThis is a sight by SIMOX, for one of his SMG's, and as you can see, when firing with such recoil / gun shaking, it is easier to guide your aim onto the target, because of the blocks and the two lines for the sight themself. They are a sort of 'support' / 'guidance' when firing whilst your SMG shakes/jerks due to recoil.
I think the line will fit best for Shotgun as it hardly has recoil/shaking when firing. Also the ironsights I've seen, the positioning is decent/good, however very few of them are too closely positioned to the gun itself, try position slightly back, so you can see the blocks on the gun.
Your model's are good, spectacular to see HD ones in there too and a large variety of types, if you just match good ironsights / scopes to them, and position them well, and to add finishing touches; to blend colour on your weapons, your weaponry collection will be really, really good.
I guess best ways to choose a weapon is,
1. Practicality - Is the sight good? Is the model to scale?
2. Looks - Does it look decent? Is it realistic to the game?
3. Will you enjoy using it, equally based on both point 1 and 2?
Regards
Vortex
EDIT: I have downloaded and will use your SG GR-47K shotgun. :)