Mean Radius Measurements

rjinga · March 10, 2017, 05:49 PM

I started looking for a target calculator program last night, and in the process I came across a term I hadn’t seen before, “mean radius measurement.” When I searched the term, I found this article that I thought was very informative and persuasive: https://www.ar15.com/forums/t_3_16/512887_.html&page=1

During my search I also came across the following quote (in a sniper forum, I think): “Three shots test the ammunition; five shots test the weapon; ten shots test the shooter.” So, with that in mind, I went back to some targets that I shot over six months ago and ran them through a target program I’m trying out. After you set the scale and mark the shots, the program determines the center of the group and then draws the rectangle through the center-line of the two or three most outlying shots, and the circle from the center point using the mean radius.

I fired ten shots each at all four targets with a Century Arms C308 rifle. The ammunition was PPU, and I was shooting off of a table using only the iron sights. I know that the 50 yd target only shows nine shots (unless that double-shot hole is actually a triple-shot hole) and the 100 yd target only shows six shots. And, I realize that those missing shots would change the dimensions on the individual target, but I included them anyway.

precision_shooter · March 10, 2017, 06:34 PM

Is the black square in the upper right corner 1"?
If not, how did you scale it?

rjinga · March 10, 2017, 07:27 PM

Yes, the black square is one inch.

March 10, 2017, 05:49 PM	#1
rjinga Senior Member Join Date: July 3, 2012 Location: N. E. Georgia Posts: 512	Mean Radius Measurements I started looking for a target calculator program last night, and in the process I came across a term I hadn’t seen before, “mean radius measurement.” When I searched the term, I found this article that I thought was very informative and persuasive: https://www.ar15.com/forums/t_3_16/512887_.html&page=1 During my search I also came across the following quote (in a sniper forum, I think): “Three shots test the ammunition; five shots test the weapon; ten shots test the shooter.” So, with that in mind, I went back to some targets that I shot over six months ago and ran them through a target program I’m trying out. After you set the scale and mark the shots, the program determines the center of the group and then draws the rectangle through the center-line of the two or three most outlying shots, and the circle from the center point using the mean radius. I fired ten shots each at all four targets with a Century Arms C308 rifle. The ammunition was PPU, and I was shooting off of a table using only the iron sights. I know that the 50 yd target only shows nine shots (unless that double-shot hole is actually a triple-shot hole) and the 100 yd target only shows six shots. And, I realize that those missing shots would change the dimensions on the individual target, but I included them anyway. __________________ "Yo homie. Is that my briefcase?" Sig Sauer P229 SAS GEN 2 E2 9mm; PTR 91, GI model; Chinese Type 56 SKS; Smith & Wesson Shield 9mm Last edited by rjinga; March 10, 2017 at 08:16 PM.

March 10, 2017, 06:34 PM	#2
precision_shooter Senior Member Join Date: September 8, 2007 Location: DFW, Texas Posts: 2,475	Is the black square in the upper right corner 1"? If not, how did you scale it? __________________ "Laws that forbid the carrying of arms...disarm only those who are neither inclined nor determined to commit crimes...Such laws make things worse for the assaulted and better for the assailants; they serve rather to encourage than to prevent homicides, for an unarmed man may be attacked with greater confidence than an armed man." - Thomas Jefferson, 1776

March 10, 2017, 07:27 PM	#3
rjinga Senior Member Join Date: July 3, 2012 Location: N. E. Georgia Posts: 512	Yes, the black square is one inch. __________________ "Yo homie. Is that my briefcase?" Sig Sauer P229 SAS GEN 2 E2 9mm; PTR 91, GI model; Chinese Type 56 SKS; Smith & Wesson Shield 9mm