Has anyone else had a problem getting a 716i upper onto a Michigan Industries receiver rod?

After some investigation it turns out the brass deflector is a pin-in part, and the part inside the receiver is not flush with the recevier wall. My rod is hitting that little protrusion and binding up.
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I have a small punch set around here somewhere - once I find it I'll pop the retaining pin out and try again without the deflector installed.

Can someone verify if it's just a roll pin holding the brass deflector insert in place?

It is. Same thing happens with a Geissele reaction rod. Remove the deflector and you'll be fine.

Thanks for the confirmation. I guess this is one of the challenges of playing in AR-10 land vs Ar-15 land.

I finally got the deflector insert out. It might have worked better if I'd gone from the bottom instead of the top. From the top, I ran out of 'skinny' on the punch and hit the top rail. It's weird though - a chunk of coat hanger is just the right size to finish hammering it out.

The upper was still a bit tight even after removing the insert, and the bolt lugs brought up some burrs on the rod's teeth. (side opposite the deflector) I filed the burrs off as I went, and got it most of the way on. I made an attempt on the FH, gave up and put some Kroil on it for an overnight soak. The next day, tried slamming it home a few times, filed off a few more burrs, oiled the rod again, and darn if it didn't finally go all the way in.

You know how your Dad taught you to tighten lug nuts by waiting for a cracking noise? That dang FH gave a few little cracks, but stayed put till I wrapped an arm around it and twisted with my whole body. The crack was loud enough I though something had snapped... but it was just the FH breaking loose.

After all was said and done, the only casualty was the little plunger assembly coming out of the ejection port door. I'm debating if it's worth calling Sig for a replacement or if it's a sign to put something fancier on.