SLW Barrel Shootout – Ammunition Testing Overview

During our semi-lightweight barrel shootout we were able to test ten separate loads with 60 shots of each ammo type through 3 barrels.  This is in no way a complete view of these particular brands of ammunition it is simply what we found on two particular days of testing.

An important note before I go into detail about the process is that we fired every round without knowing what brand of ammo and barrel we were using.  We also fired and logged every shot from start to finish.  It is very common to see reports of great accuracy without mention of group reduction techniques like shifting the point of aim, reducing the shot count or eliminating shots as fliers.

The night before our test we opened up each box of ammunition and randomly selected one out of every six rounds that would be tested.  With this small ten round sample of each ammunition we measured each round for weight with a GEM Pro-250 Precision.  With these raw weights we later pulled the average, extreme spread and standard deviation.  The principle behind this quick check was that if a round had a high deviation in weight it was possible that the charge, bullet or case weight was off.  We have not combed the data along side of group or velocity information but may in the future and we found that it would be better to have the data and not use it than to want the data and not have it.


On the first day of our test we put the LabRadar chronograph into place and started recording strings of 10 shots as we fired them.  The chronograph preformed well omitting only a small handful of shots.  We took great care to go through a checklist before firing each group and our diligence helped to keep all data separate and accessible.

The shots for this test were fired over two days.  Atmospheric data is logged for both days and checks were made using a Kestrel 4500NV weather station.  The shots were fired in two configurations.  First was a ten shot group using a Harris bipod with a rear squeeze bag.  The second was two, five shot groups from a Caldwell rest and rear rabbit ear bag.  A spotter oversaw the LabRadar as well as watched for safe impact of each round.  In one instance a correction had to be made when switching between barrels.  The nature of the test forced us to leave that with incomplete data and that particular group is 8 rounds instead of 10.


We will present each ammo type on its own and after all have been compiled we will show a comparison on how they lined up within each weight class.  The shot groups are not particularly sexy but they are the raw groups that were fired.  Each group was scanned and processed using OnTarget which gave us extreme spread center to center figures as well as average to center of group data.  In the future we hope to do extended accuracy checks off of some of the same barrels and ammunition types.  These checks will be over a wider sample giving each group size and averages across the board.

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