Further thoughts and comments on "the first Range results with a chronograph" post of August 17th post:
A. The Comparison of "Published Technical Specifications" of factory .25ACP, which are Based upon testing Using a 2" long Barrel, and the chronograph Results of firing in a Revolver with a 10-5/8" barrel hint that the loss from the Cylinder Gap venting may result performance similarity between the Two conditions as the Percentage difference seems to be less than the Expected Variations between Factory Ammunition Lots.
B. The reported "hand load #1" (2.7 grains of Power Pistol and 50 grain FMJ bullet) seems to hint at a 7.6% drop between Calculated and Measured Performance. This is Probably due to the "QuickLOAD" software apparently not having an adjustment for loss from the Cylinder gap. Perhaps using 11" for the Barrel length instead of 12" would mostly compensate for the Gap 'error'?
C. The reported Hand load(s) #2 (Various ladder Bullseye charge weights and 63 grain Lead bullets) appear to indicate a gain in velocity for the Actual performance ranging up to about +15% in one case (nominal 1.43 grain charge) and ranging down to a low of -0.85% (nominal 1.53 grain charge). Perhaps the difference between FMJ and Lead bullets filing of the Cylinder Throat, Throat to Forcing Cone, and final Barrel dimensions is in play here.
D. The Ladder Sequence seems to indicate a charge of Bullseye of around 1.77 or 1.80 grains yields the most uniform velocities measured (ES of 60 and 54 fps respectively) with this bullet in this Case size.
E. However, there is still the Problems I have in Accurately measuring charges weights at 0.01 grain interpolations of these low charge Weights (under 2.0 grains total weight). Normal procedures to measure small weights is to use a Scale with a resolution at least four times Finer than the the weight increment desired. in this case 0.01 grain accuracy would indicate a needed Resolution of .0025 grains or Finer.
F. For the time being (last two weeks of August) I am not able to do any more testing due to the Chronograph Screens needing replacements; which need to be ordered when I again have some Discretionary Spending funds available.
Perhaps I will be able to proceed in September, but that is 'Iffy" as I have Fresh Bills that will again come due in September that were not needed in July or August (example: House Earthquake and Liability Insurance renewals).
Best Regards,
Chev. William