what charge throw is acceptable to you? fixes and musings.
this is a little long, i'm trying to observances out there that maybe some else may benefit
or at least make some go HMMM?
yet others will think i'm nuts.
Pistol round shooters,
how far off does your charge throw need to be before you dump it and try again?
I've mounted a quest for perfection as i'm "OCD" when it comes to powder throws. (other stuff too.)
here's some of what i've done....and some of my observances and fixes implemented.
I'm currently using unique powder and a case activated hornady powder measure.
1. I tried to to use it as it came from the box with a really good cleaning job and after running 5 full hoppers thru it to coat everything inside with gun powder dust (i've been told it's similar to "graphite" dust.)
observance= the throws were all over the scale...5 to 6 tenths of a grain high or low.
2. I added a vibrator at the top of the throw to get every granule out of the measure drum.
observance= it helped but not too much.
3. So... I added a switch to facilitate vibration at the bottom of each throw as well as the top to vibrate the powder into the charge drum as well as out of the drum with some consistency.
observance= it helped, but was still 3 to 4 tenths off at times but would hit my target mark more often. the high or low charges were erratic ...even with a constant cadence they still occurred.
4. I took it apart and examined each piece ...on the linkage I filed or sanded all the burrs off and polished each piece ...even the end of the measuring stem.
no change
5. pulled everything apart ...again... this time i examined the drop tube that screws into
the bottom of the measure body. it appears to me that the bore thru it was done on a lathe with a small boring bar ...they drilled 1/2 way thru it ...then took it out of the chuck, reversed it then drilled thru to complete the boring step. i'm assuming that it was done in 2 steps to keep the boring bar from walking off center too far.
observance=the bores did NOT perfectly line up and created a shelf like edge in the center of the drop tube. PLus ...when the lathe operator reached the center he backed out the boring bar while it was still spinning , leaving a spiral record groove from end to end. Dear hornady , how hard wood it be to run a ream thru there?
sanded and polished to high shine with diamond paste. did the same with the caliber specific belling funnel.
6. examined the internal area of the measure body ...made of cast iron i think.
the inside was rough as could be. the throat and the area right below the baffle was as rough as
40 grit sandpaper ...then hornady powder coated the insides of the body red.
fix= i used a dremel tool grinding ball on a whip to smooth out the roughness and the i used a brake
cylinder hone on a drill press to polish the internal funnel and measure throat tube.
next came a cleaning job a surgeon would approve of.
assembly ...it was a pretty sight to behold.
ANd with all my careful work ....the throws are better ...but still will drop a charge 2 to 3 tenths off
at times...it hits the target number of 5.6 grains of unique often then the "off" charge might hit 2 or three times then it hits normal for a while...then off, then on, driving me nuts!
with the anal retentive attitude of achieving perfection by removing as many variable flaws that could mechanically be an issue ... my final observance is that the powder granules are NOT of UNIQUE size!
pun intended.
smaller granules = heavier load ...medium size = target load...larger granules = lighter load.
i think to achieve the most consistent powder throw with this measure as it is now , will be the use of
powder with very small granules like #5, #7, H110, win 296, to get the void in the measure drum to fill on each throw more consistently.
so .....how far off will you accept a powder throw?
another observance ....beam scales are WAY more accurate than a measure ...even more than electronic scales.
try this:
turn on your electronic scale...zero it with the pan on it.
pour some powder (any kind ...even sand or salt will work)
scale at zero...take a pinch of sand and slowly rub the sand between your fingers into the pan ...slowly! if you are slow enough the scale will still read zero.
you can do this until the pan is full AND it will still read zero.
even the scales on hornadys electronic powder measures will do this.
sorry for being so long winded.