fred815 Posted October 21, 2012 Posted October 21, 2012 Been having some cato's etc. with 3 lb Hand Rammed stingers?? I use thoroughly ball M. BP with airfloat or my own homemade willow charcoal. After bruising my eyes researching I see a few theories I'm a little concerned about. 1. Using simple milled but UN ganulated BP?? 2. Raising vent/fuse hole?? Considering I use expensive tooling (with their no pass lines) #2 seems unlikely. Anyway most so called authorities claim stingers are pretty forgiving. Mmmm mine must hate me??lol I've tried straight bentonite, skylighter's oven baked and waxed nozzels, eeeeeeeeetc. standard recommended Bp fuel formulas (NO Binders) So what gives?? From experience I'm betting it's something really stupid simple??? I did notice poor spin ups?? I use instant Cyno.. glues on fuse?? I think I covered it all ( so you won't have to ask all those what are you doing here or there Questions)?? Help
nater Posted October 21, 2012 Posted October 21, 2012 I think granulated BP presses or rams nicer than mill dust. Try it and see if there is a difference Have you tried using a press?
Mortartube Posted October 21, 2012 Posted October 21, 2012 (edited) At 3lb. I would suggest that a press is a must. Also your BP may be too fast. Just add 1 or 2% extra airfloat to tweak it a bit. The bigger the I.D, the slower the powder needs to be as there is a larger gas producing surface area when lit. If you look at BP rocket mixes, you will see that the larger they get, the less KNO3 and more charcoal the mixes contain, precisely for that reason. If you have poor spin ups, could your side vent be too big? What size is it? Do they CATO immediately or spin a bit then Cato? Edited October 21, 2012 by Mortartube
Col Posted October 21, 2012 Posted October 21, 2012 If you scale a 4oz spindle up to 6lb, the ratio of surface area versus size/weight will be exactly the same
Mumbles Posted October 22, 2012 Posted October 22, 2012 The one thing I don't think you covered is what type of tubes you're using. This might have an impact on their performance. I don't think the glue would have that big of an impact, but have you tried just friction fitting a fuse in as a test?
pyrodundee Posted October 23, 2012 Posted October 23, 2012 I dont know if it will be helpful but, I tune my stingers by blending my current fast bp straight from the mill (home made willow) with an old batch of bp that was WAY too slow due to crap bbq charcoal. This makes a good use for what otherwise would be a failed waste.
fred815 Posted October 23, 2012 Author Posted October 23, 2012 thanks mu....? Didn't think of testing fuses that way. BTW Hobby Horse nept tubes only. And using matching machined fuse/vent hole jig. Like I said I only hand ram. So I don't care what's nicer neater etc. So I rally appreciate the last few comments!! KISS principle for me. BTW which bp formulas (ratios) do you recommend?? 75... 60... ?? use airfloat or willow/?
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