I built an upper around an 18" Faxon gunner profile because 90% of the 3 gun stages I shot are under 100 yds. I thought it would be light and fast. Its 50% CEP is 1" @ 100 yards, so while it is pretty poor shooter by internet standards, it is serviceable for a sport where the small targets are 3-4 MOA. Anyways, the internet told me that skinny barrels walk, so I figured I better due a mag dump to figure out how much.
My local 100 yard square range gets antsy if you don't pause for at least 3 seconds between shots (so like 10s if you're under 70). I ended up shooting six five-shot groups in about 180s. This is way over a typical par time for a stage, but the best I could manage. A typical long range stage is more like 30 rounds in 50s. The weather was a frigid 50, so not the typical 100 of a summer match either. For ammo I used 55 gr Hornady soft points in mixed brass reloads, which is pretty close to the hoser loads I usually use for 3 gun. They were not the FMJs that make the local range officers upset (or the TMKs the cannot differentiate from FMJs) . I also shot the same course of fire with a 18" Criterion straight 0.75" barrel to see what a typical 3gun barrel would do. Both uppers are free floated. The Faxon had a 3-14X power primary arms scope instead of its usual 1X optic. The Criterion had a Viper 1-6X. Both were shot at max power.
After shooting I digitized the targets and extracted the X and Y shot coordinates for each shot in the group (I don't know the individual shot order, just the group order) to look for horizontal or vertical "walking". If the barrel walks either the mean x and y position (or both) of the group would change as the group number increases.
As the chart above shows, there is really not much to see.
A quick Tukey's HSD test shows that the only statistically different pair is 2 and 6 for the x coordinate of the 18" Faxon (p =0.1). Given that the test looks at 60 different pairs it is not surprising to find one pair that is different due randomness alone. In short, neither the Criterion, nor the Faxon showed any signs of walking. Both shot about the same size groups, so I suspect either the ammo or the shooter is limiting the accuracy of the system.
All and all I pretty happy with the gunner profile. I'll see how it holds up to being thrown into dump barrels.
PS I would have posted this at BEnos, but that place is dead.
My local 100 yard square range gets antsy if you don't pause for at least 3 seconds between shots (so like 10s if you're under 70). I ended up shooting six five-shot groups in about 180s. This is way over a typical par time for a stage, but the best I could manage. A typical long range stage is more like 30 rounds in 50s. The weather was a frigid 50, so not the typical 100 of a summer match either. For ammo I used 55 gr Hornady soft points in mixed brass reloads, which is pretty close to the hoser loads I usually use for 3 gun. They were not the FMJs that make the local range officers upset (or the TMKs the cannot differentiate from FMJs) . I also shot the same course of fire with a 18" Criterion straight 0.75" barrel to see what a typical 3gun barrel would do. Both uppers are free floated. The Faxon had a 3-14X power primary arms scope instead of its usual 1X optic. The Criterion had a Viper 1-6X. Both were shot at max power.
After shooting I digitized the targets and extracted the X and Y shot coordinates for each shot in the group (I don't know the individual shot order, just the group order) to look for horizontal or vertical "walking". If the barrel walks either the mean x and y position (or both) of the group would change as the group number increases.
As the chart above shows, there is really not much to see.
A quick Tukey's HSD test shows that the only statistically different pair is 2 and 6 for the x coordinate of the 18" Faxon (p =0.1). Given that the test looks at 60 different pairs it is not surprising to find one pair that is different due randomness alone. In short, neither the Criterion, nor the Faxon showed any signs of walking. Both shot about the same size groups, so I suspect either the ammo or the shooter is limiting the accuracy of the system.
All and all I pretty happy with the gunner profile. I'll see how it holds up to being thrown into dump barrels.
PS I would have posted this at BEnos, but that place is dead.
