Is a standard deviation of 36 good?

[tyroneweaver]

This is velocity of 10 shots from a .22 rifle

1044
1229
1203
1185
1170
1224
1223
1201
1154
1173

The deviation is 36, I think. So is it good, bad, so so.

 

[konradv]

This is velocity of 10 shots from a .22 rifle

1044
1229
1203
1185
1170
1224
1223
1201
1154
1173

The deviation is 36, I think. So is it good, bad, so so.

Don't know, but it looks like you got shorted a few grains of powder in that first one. Take it away and your SD should tighten up quite a bit.

EDIT: BTW, I got 27.

 

[Darkwind]

That would be bad.

 

[Flash]

I do a lot of .223 and .308 reloading.

I try to keep my general range load std dev for 3000 FPS .223 to 30 FPD or so. For 2500 FPS .308 to around 25.

For more precision loads I try to make it single digits. If I can get to five that is great.

If I was shooting 1,000 yds it would have to be 0-3.

For .22 your spread is pretty bad for anything other than tin can plinking.

 

[zaangalewa]

This is velocity of 10 shots from a .22 rifle

1044
1229
1203
1185
1170
1224
1223
1201
1154
1173

The deviation is 36, I think. So is it good, bad, so so.

1st step: eliminate runaway values. In this case lowest value=1044, Highest value=1229.

Average is 1191.625
sigma is 23.7799

Theoretically this means in 2/3 of all cases the velocity is 1192±2% and in 95% of all cases the velocity is 1192±4%. But the sample size is very little - so this result is not very reliabale.