Brass inconsistency

[CoachChris]

I've had these comparators since Hornady first came out with them.
I've never had this issue before.

I have a neck sizing die. I'm going to follow that recommendation.

Thank you for your input

 

[cbuck516]

Does the reading change as you spin the case? Hornady is known for making oblong holes in comparators.

I changed to SAC comparators and Mitu calipers, and I now get more consistent readings. At each step of my progression from Hornady to SAC, and $20 cheap-o to Starrett analog to Mitu digital calipers I get me more consistent measurements.

That is another really good point. Cheap digital calipers are not comparable to Mitutoyo at all. I had a Frankford arsenal years set years ago and it was really inconsistent. I use whidden shoulder gauge and Mitutoyo calipers these days. However, I think he is saying that he consistently is getting the same measurements.

My first question when I saw the original post was actually, why not just develop your load with brand new brass? I did that last year for a last minute elk load that I was working on and found a 1/2MOA load pretty easily and continued fireforming my brass after I came home with a full cooler. It can certainly be done. It's a little late for you to do that now, but it worked for me and I wouldn't hesitate to do it again when using premium brass.

 

[CoachChris]

That is another really good point. Cheap digital calipers are not comparable to Mitutoyo at all. I had a Frankford arsenal years set years ago and it was really inconsistent. I use whidden shoulder gauge and Mitutoyo calipers these days. However, I think he is saying that he consistently is getting the same measurements.

My first question when I saw the original post was actually, why not just develop your load with brand new brass? I did that last year for a last minute elk load that I was working on and found a 1/2MOA load pretty easily and continued fireforming my brass after I came home with a full cooler. It can certainly be done. It's a little late for you to do that now, but it worked for me and I wouldn't hesitate to do it again when using premium brass.

I have Mitutoyo calipers.

In hindsight I wish I had not fire formed them first

 

[CoachChris]

Your measurement doesn't sound correct, all my 300's measure 2.269-2.270" in a Hornady comparator, are you using the .420 size comparator?

Cheers.

I over pressured 2 cases and got a dimension of 2.2765 with the 420 comparator

Johnny's Reloading Bench has a 300WM video from around the same timeframe that I bought the Norma brass.
He had the same inconsistent sizing issues I'm having with the Norma brass. He scraped it for ADG.

I ordered 250 pieces of Peterson's long brass that are scheduled to be delivered here in 2 days
At least I know it's not me

I'm just going scramble to get a hunting load worked up on the new brass and get out elk hunting this weekend.


Thank you for everyone's input

 

[Mikecr]

This is why I dip anneal before fire forming. A few firings as mentioned earlier, along with NS only.
Then I use the Wheeler method to lock in on shoulder bumping.
If with this, some brass is not forming with others, I would toss the offenders.

 

[L.Sherm]

I have Mitutoyo calipers.

In hindsight I wish I had not fire formed them first

Atleast getting 1 firing on the brass before load development is paramount in my opinion premium brass or not.
You run some upper end loads on new brass is a good way to kill primer pockets on new brass also.
Loads will change from new to fired brass you may not see at 100 but you will farther out just like .003 seating depth tests. If brass isn't fireformed first before load development then there's no sense in doing a fine seating depth test.