M4 Hammer Bushing Question

[JonLancewood]

Sorry if this is obvious and readily covered but when reassembling an M4, should the snap ring clearly slip into the two side grooves in the hammer bushing? With both parts out of the trigger housing, the snap ring does not slip into these grooves for my shotgun. Is this normal or did I damaged something here? It's not even close on my parts. I don't think I damaged anything but the fact that there seems to be no positive interface between the snap ring and bushing has me wondering.

Thanks!

[Evolution]

This excellent tutorial will show and explain how the snap ring interfaces with the trigger bushing and how to properly install and remove it.

 

[Evolution]

Thinking maybe I should've answered with what I understand about it to better help you. The answer is yes, if the snap ring is installed in the correct position, it should engage the slots however slightly, it may not look as though the ring has engaged the slots but it has...just enough to keep the bushing from backing out of the frame.

Anyway hope some of it helps.

[JonLancewood]

Thanks for the reply and link. I used his guide for installing a FFT trigger pack and it's how I arrived at this question. While assembling the bushing and snap ring, I'm wondering what's going on with the groove and ring interface. I measured both with a pair of calipers and found the two grooves to be 0.0290" and the snap ring to be 0.0390". Physically, the snap ring cannot seat into the grooves on the bushing. Is this normal? If so, how do these two grooves manage to keep the ring in place? 

[Evolution]

I could be wrong as I have not taken apart my trigger group for at least two years but, does the snap ring not narrow in thickness as it curves up to the opening on it, and this allows the ring to enter/engage the slots?