the lube is there to seal the rifling cuts as much as anything else.
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the lube is there to seal the rifling cuts as much as anything else.
Might be an interesting concept but sound expensive to machine to me.
I don't care how well it works, I am not paying 200 dollars for a well made two cavity mould.
If you go putting dimples in bullets it will do some interesting things to the way it flies.
Gear
Yes, yes, the dimples must be below the line-of-sight of the wind, both before and after the speed of sound. They would have to be below the bearing surface, for sure, like well within the lube groove(s) to be absolutely safe. ... felix
More worried about balance because the rotational speed will be high enough not to allow much air to accumulate for a pressure wave. Compare to a curve ball / knuckle ball. ... felix
Dimples belong on a pretty woman, not on a boolit! Not even a pretty boolit!
Think about it.... if some dimples purge and others don't.... what have you gained?
But multiple very small grooves has shown merit for me as of late. Even Lee tumble lube bullets used with conventional lube (if our mixes can be called conventional) have shot groups tighter than I would have believed. I run them neck and neck with standard one or two groove comparable boolits. My soft alloy and concentric sizing is a bear to achieve however....but long tapered nose first sizers will make them shine....
Eutectic
Yaw! Kills the kat every time! I have always had problems with boolit bases! Even gas checked ones! There is something to be said for spending hard earned cash to obtain a well made "bump" die to finalize a checked boolit. ... felix
Felix,can you explain the bump die to finalise a boolit?. Pat
a bit of swaging.
some dies bump the nose for a better fit and some will reshape the whole boolit.
you have to de-lube and oven harden a whole boolit swage though to regain hardness.
a good swage will also remove air pockets.
Realize this is somewhat of topic, but. Dimples on golf ball are to limit velocity and allow controlled 'english' - the cut from a slice is most detrimental to accuracy. The lube groove is the weakest part of a CB(well, OK, the base really is but we're probably talking GC's here). Dimples in a ring like a lube groove don't cause as bad behavior in flight as a GROOVE. Rotational velocity may be slowed, but I suspect it would still be laminar flow and not really make any difference in flight. The dimples would have to be swaged in, then CB resized and lubed. Somewhat similar idea to Eutectic's with the thin grooves that purge smaller chunks of lube, I think the Lee design was intended to be filled with LLA, not tumbled. Dimples actually will purge better than a groove. Not enough time left in my life to play with this. Enough said.
Yep.... A set of different 'bump' dies for all our favorites may be the epitome for our accuracy quest! Several things could be improved. Lube grooves could be swaged more shallow by bumping with grooves empty? Probably more importantly ogive to lead could be matched. The base/gascheck being square and tight another big one.
Gaschecks are another item I've played with quite a bit. Lately, I've been shooting Hornady checks which I have fully annealed. (Well almost.... about 1250F) Almost without exception accuracy has improved. The sizing process (which I do nose first with pressure applied to the boolit nose) tends to swage/flatten the gascheck area almost 'bump' die like. A benefit from using my soft 8.5 bhn most of the time with low sectional density boolits.
Gascheck shanks on boolits...... Why are they normally so long? To carry more lube? We have too much lube now most of the time! Some say for clearance for lead flow from rifling engraving. I tend to wonder how much of this is 'keyboard' theory vs. actual experience? I have modified a lot of different boolits, both plain base and gascheck, to test some of my theories on boolit design, weight, twist rate used, etc. etc. I have machined gascheck shanks only enough for the gascheck to fit lengthwise. Accuracy has been excellent with this method and recovered boolits showing no sign of the gascheck 'being wedged' off. Actually, they look quite professional on recovered boolits. KIND OF LIKE THEY WERE SWAGED ON.
Lots and lots and lots to look at for the very best cast boolit accuracy...... Lube and it characteristics and behavior only one.... A big one I'll admit.
Eutectic
Can we start a new thread explaining the swaging/bump sizing process?. Pat
go for it...
you'll get a lot more reply's on a new thread.
You could start a new thread Pat. Some here may have some 'gems' to offer... A couple could probably even make them.
A 'bump' die is sort of a slang term for a custom made sizer/forming die for cast boolits. They are made in several different designs and are precision and very complex machining. Tool & Die work at its finest! Read $$$$$$$$$$$$$$$$$$$$$$$$
Hard cast/water hardened boolits can be precision sized by a 'bump' die. By this, body, ogive, bore ride section can be trued-up both in circumferential and longitudinal alignment and precise diameters. Correct gascheck fit and squareness can also be achieved.
Softer alloys can be reshaped even more. Base modifications like heeled boolit designs, custom diameters, lube groove reduction, nose shape, HP's...... Just depends what you want to pay for as to special nose and base punch tooling...
You do realize your interest ventures into the PhD areas of cast boolits? If one minute of angle accuracy just isn't enough...... Then this area can be an exciting adventure for you to travel!
Eutectic
For rifled bores, assuredly, but this might be the aerodynamic innovation those sneaky Europeans with their Brown Besses and Charlevilles have been looking for. Better keep this quiet, or the redcoats will be burning D.C. again. That, or the Scots will start playing golf with gunpowder. Given the alcohol typically involved, that can only end badly. :mrgreen:
Bruce, got your package today, many thanks!
This additive is the stringiest stuff I've ever seen in my life, makes Lucas oil stabilizer look like water. I can see why a half-percent or so does the job. I look forward to playing with it a bit, I think I'll divide up a couple of test lubes I have and add some to do a comparo.
Gear
got mine yesterday,as i was loading the 4 wheeler on the little trailer.
opened the box and shook the bottle a bit before leaving it is sticky stuff,ill have to get some in the E-lube [fail] and see what happens.