Gap between upper and lower

Hey, new guy here (already posted this to the Welcome Forum but thought I'd try here as well).

I do have a question. Installed the SureFire kit today and when I put it back together noticed a significant gap between the upper and lower near the barrel on the right side, see photo. I searched the forum and found some discussion in the Accuracy thread but was unclear whether this was a defect that needed to be fixed or just the way it is.

Seems like it would definately impact accuracy since the sights are on the upper.

Checked and the adapter ring is not contacting the shroud, I can push and close the gap pretty easily.

Any help appreciated.

Brian

One data point is CatMostFeared's SBR:

Looks normal to me. The upper/lower halves aren't water tight or anything. Vector isn't really made to do 800 yard sniper shots either.

I never noticed that on mine. But I dont run the SF in the housing anymore. Instead I put a rail at the 11 o'clock postion on my barrel shroud. I have since removed the SF adapter since taking this pic. But it looks like my receiver might have some gaps as well.

Checked my CRB and when flexed it is the same size gap. Would think it appears normal, and would be hard to make it Sig tight because of the way the assembly pins are attaching the FCG to the barrel assembly?

Thanks for all the feedback.

Consensus so far is that it seems normal.

I'll try an experiment this weekend if I can get to the range. I'll strap down the upper and lower to close the gap and see how accurate at 25yd and then try again with the gap opened up. Will post results but agree, it's certainly not designed for long range accuracy.

Brian

I can flex mine and get the same gap

Mine is the same.

When I put my E1B back in I noticed the gap in mine as well.

Spent some time with it today and figured it out.

With the SF in the wire out the back of the SF comes between the upper and lower joint and pushes them apart. The wire is tapered right out of the back of the light and the thick part was caught between. It's flexible so they can still be squeezed together easily.

I pulled the SF forward so that only the thinnest part of the wire goes in the gap and it's better but not perfect.

Need to think about rerouting.

Brian

Try staggering the pin placement.