Brass processing problem

[Three57]

I have been following the long range hand loading threads as closely as I can. I need 300 loaded rounds for a long range class that I have coming up. I am using a semi-auto 308. Here is the problem I am having.

I have sorted my new Winchester brass by weight. It has been suggested to work new brass as little as possible, so my thought was to not resize it, but to just measure the headspace to make sure they are sized correctly. To do this I adjusted my sizing die with the expander ball all the way down so that it will only round out the neck, I then turn the neck as per the brass processing thread, and measure the headspace. I am coming up with 4 different sizes for the new brass (1.618, 1.619, 1.620, and 1.621). Fired brass from my chamber measures at 1.628, I will later resize my fired brass down to 1.625. My question is about the different headspace lengths. Do I sort them in to groups? Do I resize them all down to 1.618 to make them consistent? I could also resize and sort them in to two groups 1.618 and 1.620? Which option will be the most accurate? How much do I sacrifice by sizing them all down to the same size? I am just unsure of what this will cause and the correct course of action.

Thanks for all your help. I know you guys can lead me in the right direction.

 

[Sniper Uncle]

I have been following the long range hand loading threads as closely as I can. I need 300 loaded rounds for a long range class that I have coming up. I am using a semi-auto 308. Here is the problem I am having.

I have sorted my new Winchester brass by weight. It has been suggested to work new brass as little as possible, so my thought was to not resize it, but to just measure the headspace to make sure they are sized correctly. To do this I adjusted my sizing die with the expander ball all the way down so that it will only round out the neck, I then turn the neck as per the brass processing thread, and measure the headspace. I am coming up with 4 different sizes for the new brass (1.618, 1.619, 1.620, and 1.621). Fired brass from my chamber measures at 1.628, I will later resize my fired brass down to 1.625. My question is about the different headspace lengths. Do I sort them in to groups? Do I resize them all down to 1.618 to make them consistent? I could also resize and sort them in to two groups 1.618 and 1.620? Which option will be the most accurate? How much do I sacrifice by sizing them all down to the same size? I am just unsure of what this will cause and the correct course of action.

Thanks for all your help. I know you guys can lead me in the right direction.

What ever you do, DON'T resize them all down to the smallest. I would sort them at most. If you resize them all down, you double work them considerably more than necessary. They are all ready smaller than the chamber by enough that your fired and resized brass will be larger than the new brass you are starting with. Resizing it now will only increase this size change, and you will have done it twice---once smaller, and then fired bigger. I would lean towards sorting into two groups, larger and smaller.
Others could shed more light on how much you are actually changing your group size potential with this size difference in brass.

 

[turbo54]

Forget about it; load them and shoot.

As an aside, I think you're wasting your time neck turning.

 

[RampedRaptor]

I'm still a major noob in the LR game and also reloading but since no one else has replied I'll throw out my .02. EDIT: I need to type faster!

I think you need to FL resize your brass then the next firing if you choose, you can neck size or two step size to your liking. By FL resizing now you make the brass all the same "damn close" dimensions. No need to size all the way down and "over work" your brass but just enough to get all of them on the same page. Then instead of sorting by weight you may sort by internal water volume to better the results.

You don't want to over work your brass but you don't want to show up to the first day of class with only 100 of those 300 being able to chamber properly. Hopefully this all fairly clear

 

[Pinecone]

I noticed that my new Lapua brass has very tight necks.

IIRC the inside diameter was around .302 for a 6 thousandths neck tension. I ran them over an expander to get the neck tension a bit less.

 

[Three57]

The reason I am turning the necks is because they are inconsistent and I had previously believed that to be causing the bullet runout that I was getting. Inconsistent necks will cause runout, but I am turning the necks just for consistency in my load testing. Once I have my load I will test how much of an accuracy difference turning makes and whether or not it is worth it. I am just not to that point yet. I have found that most of the runout is inherent in the case itself and I have found a different solution for fixing that.
I am agreeing with sniper uncle, sorting in to two groups makes a lot of sense. As long as the group is big enough to get what I need.

 

[Sniper Uncle]

Forget about it; load them and shoot.

As an aside, I think you're wasting your time neck turning.

OP, please think very hard about Turbo's advice. He knows a lot more than I do. I personally would do just what he said, forget about it, load and shoot.

I would run the ball into the necks to make sure they are round, that's it. I recommended the sorting into two groups only as the very max to do. I wouldn't do it myself.

 

[Three57]

Well that will definitely make things easier.
I will try it. I can use the brass I have already done this work to for load testing and just use the rest the way it is.
Can you tell me how much accuracy, if any is at stake?
I firmly believe that I can get ½ MOA groups out of this rifle.

 

[Three57]

MtnCreek,
I do plan on putting a few hundred through it before the class. We will be cleaning the rifles at the end of each day in the class, so getting dirty shouldn't be much of an issue. The new brass is already way under the size of the chamber, I have fired 100 rounds through it so far. I shouldn't have any problem with reliability. Thanks for your input.