Delta IV,
Sorry to hear about this occurrence, but at least the Intrepid has proven rocket stable and the damage isnt severe.
From the looks of this, it appears you have about 30" of BT-60 being pressurized by an F20's ejection charge. That should have blown this apart even if something was on the tight side. For instance, I have a glider or two that always ejects with force with an F20, and moving around 8z in doing so.
What I do to test whether something will eject correctly on any glider depending thereupon is what I call the 'blow test'.
Hook up and prep your glider as if ready for boost, without motor though. Then, pucker up and blow into the MMT with a hard quick breath of air. Whatever you intend the ejection charge to move should certainly do so when you do this. If there an ejection gas leakage, you can find this by running your hand along the seam or anywhere you suspect such is occurring.
Bear in mind that the ejection charge of any AP motor is going to be LOT stronger than your 'blow force', so anything that passes this test several times is typically good to go.
As to your design, double check anything that has to slide or separate, such as that rear pod/mount on your Intrepid. I dont think the chute shouldve been that tight, it cant be over 18-24" inside a BT-60. If there isnt any ejection gas leakage, then the blow test should separate the rear section from the glider and likely dislodge the glider from the nose cone pegs.
Another sneaky thing with ejection pressure leakage. If its occurring more than a few inches ahead of the motor itself, you wont tend to have any residue at the fault area. You do have some sort of bulkhead, and that will 'collect' most of the forward solid particle matter from the charge, so less to 'dust' the seams.
Overall, assuming at least a decent charge on the motor, theres only two things that can cause nonsep on such designs. Either something is too tight or there is a pressure leakage. Since you know what youre doing, its easy to eliminate the tightness part, particularly if you give the rear ejection part a good going over. Once repaired, eliminate any tightness you can, then do several blow tests. You may need to use a small piece of MMT tubing to help to blow in with if you cant get your lips around the rear correctly (did I actually say that :surprised
.
BTW, what is the span of the wing here, and how long is the chord? Might make one of these myself with the lightest stuff sitting around here.
