Save yourself the money, clear your rifle in accordance with the user manual and just do a visual bore check with a 30 caliber can on a 5.56mm gun.  No need for the rod.  If you can't see the bore, or can't look through the breech side, you can put white paper on the open bolt face and reflect light into the chamber and bore with that for a muzzle side check.  

Odds are you have plenty of clearance and it will be clear when you see it. Money and time saved.

I appreciate saving a dollar like everyone else.  Most people will be able to easily visually check a subcaliber application.  Someone with a ball hitch backed into my truck in the parking lot and I changed my bumper last night- the chrome stamped veneer thing that looks like a bumper.  

I really don't appreciate Ford Engineers now. haha  That was like a 6 hour job- seemed like bunch of plastic, some rubber stuff, 60 fasteners and every metal one had a threaded clip, none of the holes were extruded tapped holes directly in the sheet metal to save all the dicking around with worn out single use designed clips.  I think I'll use the dealership for the next one- if someone backs into my truck in the parking lot again.  I drive a company truck so it's not even 100% my money if I repair it with a dealership.

I saw this youtube video and it showed 6 bolts, but that doesn't include moving all the trim and plastic and brackets and fog lights to the new part.  There has to be a better way to design that bumper.

They actually are a bit tough to make.  They get swiss turned, ground, and have to be carefully handled to keep them from being bent in handling.  They serve a purpose.  Not everyone has a good eye or even good near vision, so they help people conveniently check alignment.  But yeah we make things that people want to buy because we make a living on products that we sell.