Chronograph Evidence - Bullet Consistency

Below is the data from a 300 H&H Magnum.  We put a new barrel on the action, and I broke it in using Hoppes for removing the carbon and Sweets solvent for removing the copper.  We cleaned it again very thoroughly after the break-in.  I then shot and chronographed a 5 shot group (SERIES 1).  The group size was just over 1’.  The average velocity was 3,226 Feet per Second.  The extreme velocity spread was 49 Feet per Second and the Standard Deviation was 18.  The load was using 71 Grains of H4350 hand weighed, carefully prepared cases and 150 Grain Sierra Pro Hunter Bullets.  All cases were neck sized only cases that had been previously fired during initial barrel break in procedures.

Blake Cyrus
150 Grain Sierra Pro Hunter
300 H&H Mangum Brass
Hornady H4350 Powder
Gun Cleaning
I then cleaned the gun thoroughly using Modern Spartan Systems – Spartan Carbon Destroyer, Spartan Copper/Lead Destroyerand conditioned the gun with Spartan Accuracy Oil™ through a series of 5 - 3 shot groups.  I cleaned and conditioned between groups as outlined in the Accuracy Counts instructional video.  I then shot and chronographed a 5 shot group (SERIES 2).  The group size was just over ½”.  The average velocity increased to 3282 Feet per Second.  The extreme velocity spread was reduced to 13 Feet per Second and the Standard Deviation was reduced to 5.  The load was using 71 Grains of H4350 hand weighed, carefully prepared cases and 150 Grain Sierra Pro Hunter Bullets, the same load and same cases as series 1.  All cases were neck sized only cases that had been previously fired during initial barrel break in procedures.

SERIES 1 Data 

(group shot after break-in using old cleaners and lubes)

Group Size1.049 inches center to center

Series1Number of Shots5
Min Velocity3196Max Velocity3245
Avg. Velocity3226Standard Deviation18
Extreme Spread49

SeriesShotSpeed
113196fps
123229fps
133244fps
143217fps
153245fps

SERIES 2 Data 

(group shot after treating with Modern Spartan Systems)


Group Size0.614 inches center to center

Series2Number of Shots5
Min Velocity3278Max Velocity3291
Avg. Velocity3282Standard Deviation5
Extreme Spread13

SeriesShotSpeed
213278fps
223291fps
233282fps
243282fps
253278fps

All chronograph measurements were taken with a Magneto speed chronograph.  All tests were shot on the same day.  Conditions were; Temperature at start was 86° F, the temperature at finish was 92° F.  Partly cloudy with a gentle breeze the entire test period.


Conclusion


As you can see, after treating with Modern Spartan Systems Accuracy Oil™ and cleaning with the MSS Carbon Destroyer and Copper/Lead Destroyer the average velocity was increased by 56 Feet per Second and the extreme velocity spread was cut by over 70%, as was the Standard Deviation!  This enhanced consistency I am told by the developers is due to a smoother, harder bore after treatment.  This ultimately translates into the size of the shot group being much smaller.  I HAVE SEEN THESE SAME RESULTS WITH SEVERAL OF MY RIFLES, BOTH OLD AND NEW and know that the effects of these products on enhancing the accuracy of firearms is very real!


Translation


Blake is a career military sniper and competiton shooter.  He was able to bring his shot group down from roughly .75 MOA to .25 MOA.  This allowed him to win 1st Place in his last event.

Before and After Groups