I agree with Mark. Weather, Motor thrust/ burn rate all determine my choice.
I have had motors like V max pop the nose at burnout even with pins. Also on some rockets
Remember to put a small vent hole for pressure change on ascent.
Bear ,
You are correct the threads do go all the way through.
Any part hand made is cooler . Any time I spend working on rockets is quality time to me.
That is part of the hobby. I get just a much enjoyment building and tinkering. As I do flying.
They are cable stops. You can get them at lawn mower shops .
automotive stores. Lowes Home depot. I have even seen very small (4-40 bolt ) ones at hobby shops for RC airplanes.
https://www.ebay.com/itm/EARLY-PROTOTYPE-ROCKET-ENGINE-MOTOR-ROBERT-H-GODDARD-/370558528422?pt=LH_DefaultDomain_0&hash=item5647026ba6#ht_946wt_954 The is no way of telling if it is a fake.
It looks too good.
I have great results using this from Micheals And 40% off coupon. It is an artwork based acrylic
So it won't "attack" most paints. I have used the matte to clear coat my flat painted rockets.
mainly to protect the decals.
Bunkers are Bunk.
They are a coffin if you are inside and are found.
You best chance is a well stocked house and 20+ acres. And enough Family/Friends to patrol it. (Armed to the teeth).