Accuracy/Standard deviation

[El Sancho]

My fellow Shooters,
I need some feedback/assistance on the above subject. Question is that i have been helping
my buddy with his 7mag. We are use IMR 7828 63.0 GRS and 63.3 grs with a Winchester primer. Velocity is at 3022 & 3023 FPS @ 12'. The standard deviation is @ 5.7 & 7 the worse is 11. The first 2 shot would almost touch each other then the third would fly out approximately 1-1 1/2 away. What could cause this? Just trying too have a consistent 1/2 shooter. Barrel is 26" make shaw, bullet Berger Classic Hunter 168 gr.. Any info will be Greatly Appreciated
Respectfully
Manny Sanchez

 

[P1ZombieKiller]

What barrel contour and stock combination? How much time in between each shot? are you using wind flags?
If this is a remington 700 standard hunting rifle varmint contor barrel, and your shots were 10-15 seconds apart, I can tell you more than likely your barrel is too hot. Happens to mine.

If this is not the case, then we can look elsewhere for the issue.

 

[BoydAllen]

A couple of things: First of all, what has been done to the stock as far as bedding? If it has not been done, you are wasting your time trying for fine accuracy. Secondly, you should be looking ad ES not SD. Shooters have gotten into the bad habit of using SD because it is a smaller number, and because their chronographs calculate it. What you need to know is what the difference between your highest and lowest velocities is, ES.

 

[Steve Blair]

A couple of things: First of all, what has been done to the stock as far as bedding? If it has not been done, you are wasting your time trying for fine accuracy. Secondly, you should be looking ad ES not SD. Shooters have gotten into the bad habit of using SD because it is a smaller number, and because their chronographs calculate it. What you need to know is what the difference between your highest and lowest velocities is, ES.

[br]
+1

 

[DRNewcomb]

The standard deviation is @ 5.7 & 7 the worse is 11.

How many of what size groups are you testing? If the flyers are shots that fall in with the rest wrt MV, you may be looking at issues other than that; such as technique, bedding, wind, bullet seating, etc.