Sierra MK bullet weight variance

drgoose · August 21, 2010, 07:59 PM

I am still new to precision reloading but yesterday while working up a load I bought a box of 100 Sierra Match King .308 diameter 168 gr HPBT.

I guess because I was told I should do it I weighed every bullet and sorted them according to weight. About 50 bullets were 168 gr, about 30 were 167.9, 10 were 167.7 and the rest were between 167.6 and 168.1

I guess if I plot this and make a histogram it would kind of look like a normal distribution. So here are my 2 questions:

1)Is this variance often seen with "premium" target bullets.
2) does a variance of 0.5 gr (difference between a 167.6 and 168.1) make a significant difference in accuracy?

Brian Pfleuger · August 21, 2010, 08:16 PM

Quote:

1)Is this variance often seen with "premium" target bullets.
2) does a variance of 0.5 gr (difference between a 167.6 and 168.1) make a significant difference in accuracy?

1)

I don't see that much variance in non-premium bullets. I have many boxes of Hornady, Sierra and Speer rifle and pistol bullets and I have never seen that much variance in any of them.

Most of them are not exactly the stated weight and the trend is .1gr under stated weight. I don't have any that vary by as much as yours.

2)

It would depend on your definition of "accuracy" and at what range. For normal hunting at not more than a couple/few hundred yards they will likely shoot as well as you can shoot them.

drgoose · August 21, 2010, 08:38 PM

I am still trying to find the combination that has the biggest return on investment between increasing accuracy and time invested in the manufacturing of the handloads.

So far I have found the following have given me a significant increase in accuracy at the expense of very little effort.

1)weigh every charge instead of just using the powder thrower.
2)using Sierra Match King bullets instead of soft point bullets
3)Trying different bullet weights (my rifle apparently liked 168 gr much better than 150 gr)

Things that I am not convinced I have seen a great improvement with significant time and labor:

1)Cleaning all the primer pockets.
2)Sorting the bullets from the same box by weight

Things that are on my to do list:
1)Neck sizing only
2)Adjusting the seating depth of the bullet
3)Measuring concentricity and bullet run out

Suggestions appreciated.

Bamashooter · August 21, 2010, 09:07 PM

i just weigh sorted 200 remington 55gr. fmj that were all over the place. i use alot of sierra and that is one thing i liked is thier weight from bullet to bullet is usually pretty good. most were between 167.9 and 168.1 and to me that is very good. another good thing about sierra bullets is the fact that they are pretty cheap, but very good bullets.

August 21, 2010, 07:59 PM	#1
drgoose Member Join Date: November 29, 2009 Posts: 28	Sierra MK bullet weight variance I am still new to precision reloading but yesterday while working up a load I bought a box of 100 Sierra Match King .308 diameter 168 gr HPBT. I guess because I was told I should do it I weighed every bullet and sorted them according to weight. About 50 bullets were 168 gr, about 30 were 167.9, 10 were 167.7 and the rest were between 167.6 and 168.1 I guess if I plot this and make a histogram it would kind of look like a normal distribution. So here are my 2 questions: 1)Is this variance often seen with "premium" target bullets. 2) does a variance of 0.5 gr (difference between a 167.6 and 168.1) make a significant difference in accuracy?

August 21, 2010, 08:38 PM	#3
drgoose Member Join Date: November 29, 2009 Posts: 28	How much accuracy. I am still trying to find the combination that has the biggest return on investment between increasing accuracy and time invested in the manufacturing of the handloads. So far I have found the following have given me a significant increase in accuracy at the expense of very little effort. 1)weigh every charge instead of just using the powder thrower. 2)using Sierra Match King bullets instead of soft point bullets 3)Trying different bullet weights (my rifle apparently liked 168 gr much better than 150 gr) Things that I am not convinced I have seen a great improvement with significant time and labor: 1)Cleaning all the primer pockets. 2)Sorting the bullets from the same box by weight Things that are on my to do list: 1)Neck sizing only 2)Adjusting the seating depth of the bullet 3)Measuring concentricity and bullet run out Suggestions appreciated.

August 21, 2010, 09:07 PM	#4
Bamashooter Senior Member Join Date: March 12, 2010 Posts: 1,860	i just weigh sorted 200 remington 55gr. fmj that were all over the place. i use alot of sierra and that is one thing i liked is thier weight from bullet to bullet is usually pretty good. most were between 167.9 and 168.1 and to me that is very good. another good thing about sierra bullets is the fact that they are pretty cheap, but very good bullets.