Seems to me those comments do not really help the rocketeer trying to learn how to keep their models in one piece for another flight. Flight performance prediction isn't a black art, it's a common basic model rocket skill.
If one doesn't fly APCP they won't have to worry about bonus delays. One of the many reasons I refuse to fly APCP... Delay trains that can't be trusted.
Aside from that; It only takes a little preperation and simple math (or even simpler a sim program) to know and pick the closest delay to any model/bp motor combination in your fleet. A little pre-Launch day preperation...Not clairvoance or luck my friend. Simple Basic Mod-Roc knowledge that should be as much a part of the model rocket certification process as anything.
Taking the time to know you models and motors will avoid most of the silly mismatching mistakes that usually end in stripped chutes and/or crashed models. Failures that are then blamed on malfunctioning swivels or faulty chutes or weak shroud lines when in fact the failure was casued by the same manace that caused most Auto accidents "the Nut behind the wheel" or in these cases the guy who loaded the motor.
I've seen some of the Stainless barrel HD swivels used in deepsea trolling, rated at 400lbs. the barrels are about 1/4" in diameter. Very hafty looking swivels way to big for anything i'd ever be flying. Pretty expensive also as I recall.
Very nice... thanks for the pontification...
Sorry if I confused you using a "HPR" term; but I wasn't aware that the term "bonus delay" was strictly applied to HPR... Not having ever flown APCP, strictly flying BP, I was referring to the D12-3's I've launched that have sometimes been more like a D12-9... (and yes, I know there is no such thing). I've also had C6-5's end up with delays more like C6-8's... (again fictitious motor designation)... When you put a motor that is appropriate for the model in it and it does something it's NOT supposed to do, what can you do about it?? Your earlier statement came across as, "well, if you learn how to put the right motor delay in your model things like that would NEVER happen" when anybody who's flown awhile knows sooner or later you WILL come across a motor that is either a W-A-Y L-O-N-G-E-R delay than what was on the label, or shorter, but that's more rare, or you put a C motor in your model that performs like a wet "A" motor and barely gets it off the pad... Couple subpar performance with even a regular (meaning proper) delay time and that puppy's gonna be moving at a good clip when the chute pops... presuming it pops before it hits the ground. I recently lost a rocket to just such a happenstance.
Also, I've chosen motors with what I thought was the 'proper' delay only to find that the model hits a breeze on the way up or a gust weathercocks it soon after leaving the rod, and the rocket arches WAY more than you figured or intended, and the thing ejects near apogee but still carrying a LOT of horizontal velocity, especially if it's into the wind and a good stiff breeze at altitude which increases the "apparent" wind velocity. I've had a rocket or two strip or nearly shred a chute even though it looked to have little actual 'ground velocity' but was horizontal at apogee into a stiff wind aloft that was ripping past it fast enough to do nasty things.
Now perhaps you didn't mean to come across with this "well, if you knew what you were doing that wouldn't happen" attitude, but it sounded to me like it. I'll presume you didn't intend to come across that way. Perhaps you'll consider your word choice a little more carefully in the future, my friend...
Anyhow, yeah, it's still rocket science. Yes, I agree with you that one should ALWAYS endeavor to choose the right motor for the conditions, but sometimes that IS a learned skill, and from bitter experience, as I can attest. Difference between knowledge and WISDOM... (and experience).
However, the unexpected still can and DOES happen sometimes...
Have a good one! OL JR