Can lead be to soft !

[Jeff Murray]

Just another observation on rate of twist and range of charges.  My 50 cal. has a 40 inch Getz barrel with a 1 in 66 twist.  it will shoot anything from 65 grains up to 110 grains with good accuracy.  That is a nice range that gives you options. The tightest groups were obtained with 75 grains of GOEX 2FF.  This load also produced the most consistent velocity with the smallest standard deviation.  Above 110 grains, the gain in velocity was not enough to warrant the extra powder.  Pushing the weight of the powder residue out of the barrel likely has some effect on that result.  Experimenting with Elephant powder and a heavier charge (100 or 110 grains as I remember) produced an even tighter group with a smaller standard deviation.  The velocity was almost identical to the 75 grain GOEX charge.   Apparently this velocity is the barrel's velocity "sweet spot".

[Daryl]

I find this quite interesting, Jeff.  I found in my 42" .45 with 60" twist rate, if using a water based lube, anything from 55gr. to 65gr. 3F or 2F gave good accuracy and almost exactly the same
point of impact to 100yards.  The av. velocities seemed between 1,720fps and about 1,775fps.  Indeed, no elevation changes had to be made on the trail walk shooting gong targets. Any minor difference was taken up, I assume, by the size of the gongs.
When switching to a slippery lube, in this case,  LeHigh Valley Lube, these powder charges did not shoot at all, and I had to increase the powder charge with 3F to 75gr. and with 2F, to 85gr.
Both of these loads gave about identical velocities, just over 2,200fps.  Thus, the accuracy loads with a water based lube were in the 1,700 to 1,800fps range, but with the slippery lube, the
shot to shot variation and subsequent accuracy did not occur until the vel. was over 2,200fps. Thus, the sweet spot for accuracy depended on the lubricant used.
A .445" ball and 10 ounce pre-cut denim patch was used for both loads.  Too, identical results occurred with the railroad ticking patch material we had, which I measured at .0235" at the time, but my
new calipers measure it at .022" compressed.
Loading was easy with the rifle's 3/8" rod after starting with the short starter, of course.

[Jeff Murray]

Daryl,  Interesting observation.  This is pure speculation but your results might have had something to do with the amount of energy consumed in getting the ball started out the barrel upon ignition.  The "slippery" lube might have allowed the ball to move sooner/easier and perhaps the ball was not as well stabilized when it exited the muzzle as the other lube which might have created more breech pressure.  Maybe the extra charge and velocity of the slippery lube overcame the possible relative difference in breech pressure?  A dry or slippery bore might also have an impact?  Figuring out the puzzle is half the fun.   This "wisdom" and $5 bucks will probably still get you a plain cup of coffee in most shops. 

[Daryl]

Yeah, hard to say just why this happened.  Appears consistent shot to shot velocities and internal ballistics were not achieved with the slippery lubes, until the
heavier loads and higher velocities were produced.  Whereas, with the stickier, water based 'lubes', consistency of velocities and pressures was obtained at much
lower velocities.
No wiping at any time. Even with the heavier loads, there was never and fouling buildup, thus a consistent bore condition was maintained.