• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

help with consistent seating depth ?

@rebs I had to load up some rounds for a ladder test, so I decided to show you how consistent my seating is from good chamfering and using a mandrel expander before seating. These are 223 with Hornady ELD-M 52gr bullets with an RCBS Competition die. I did not sort these bullets at all. 2 out of the 5 were only 0.0005 off. I'll take a half thou disparity all day.

I'll try to follow this up later showing the difference when seating without chamfer and no mandrel. I have some brass that's been sized and sitting for awhile and don't have a chamfer or mandrel pass yet...Maybe I'll load up some dummies with them. Point being, consistent neck tension/seating pressure is an important part of consistent seating.

 
Last edited:
As stated above I use to experience the same thing with my 6.5 creed with redding setup. Biggest thing that help me was switching to a expander mandrel instead of the ball in sizing die. Just seem smoother force while seating and more consistent lengths base to ogive.
What brand of expander mandrell?
 
can I get an expander mandrel for my Redding bushing die ?

I have been using Berger 80.5 gr bullets and they vary in weight by 6 tenths of a grain. Also vary in base to ogive by .004. Also there was two 77 grain bullets in the box. I bought them from Midway USA. Now that I have them sorted I am going to load them in groups and see if the seating depth improves.
 
can I get an expander mandrel for my Redding bushing die ?

I have been using Berger 80.5 gr bullets and they vary in weight by 6 tenths of a grain. Also vary in base to ogive by .004. Also there was two 77 grain bullets in the box. I bought them from Midway USA. Now that I have them sorted I am going to load them in groups and see if the seating depth improves.

The Berger 80.5 doesn't need to be weight sorted to shoot tiny little bug hole groups. They also don't need to be sorted to seat within .001 or less.

I believe you have some other problem.

I would suggest loading up 20 rounds with some brand new brass and see if you still have the same problem.
 
I do not know the freebore and the Lapua brass has 6 reloads on it. THe distance to the lands is 1.936 with the Berger 80.5

I checked my seating numbers for 223.

You have approximately 30 freebore. Maybe even less. You are well below the donut. Your problem is the donut. It's gotten worse the more reloads you put on your brass. The solution is a longer freebore. Or new brass.

Do yourself a favor and take one of your sized cases and split the neck like shown in this picture (use a Dremel cut off wheel) and seat your bullet to the depth that you're seating it and look where the pressure ring is.

20220628_155502.jpg
 
can I get an expander mandrel for my Redding bushing die ?

I have been using Berger 80.5 gr bullets and they vary in weight by 6 tenths of a grain. Also vary in base to ogive by .004. Also there was two 77 grain bullets in the box. I bought them from Midway USA. Now that I have them sorted I am going to load them in groups and see if the seating depth improves.
Did you get factory seconds? I know Midway sells a lot of them. Those Bergers should not have that much variance. I checked the ones I have and they are very consistent.
 
Did you get factory seconds? I know Midway sells a lot of them. Those Bergers should not have that much variance. I checked the ones I have and they are very consistent.
They were not labeled as seconds on the box or on Midway's web site.
The part number is22427 and the lot # is P02446
 
Last edited:
Try seating a few after sizing with a std FL die, and see what happens. Hold the press handle down for 5 seconds at the end of the stroke as that's been said to help. Also, I always spin my loads 180 during seating.
 
Is it the Redding bushing sizing die that causes the donut because it doesn't completely size the entire neck? I do not see or measure a donut if I size in my fl Hornady die
 
Is it the Redding bushing sizing die that causes the donut because it doesn't completely size the entire neck? I do not see or measure a donut if I size in my fl Hornady die

Partially, yes.

The donut is simply a phenomenon that happens from resizing brass vertically from top to bottom. Over time material gets moved down the neck and forms a funnel. It doesn't have to necessarily be a hard spot, which is what most people think a donut is. A donut is a thickening of the neck at the base toward the shoulder so you get more and more neck tension as the brass gets older and especially as it gets stiffer.

So you might find that some sizing dies with the expander ball show less signs of a donut but actually it's still there.
 
If using a bushing die to size the neck, if you don't size the neck all the way to the shoulder then the bullet can go deeper than the donut but not be affected by the donut, right?
 
If using a bushing die to size the neck, if you don't size the neck all the way to the shoulder then the bullet can go deeper than the donut but not be affected by the donut, right?

That is what I used to do with the 243 and it did work. Because I was seating below the donut. So after the brass have been fired a few times I only sized half of the neck. And that did work.
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
167,570
Messages
2,235,902
Members
80,597
Latest member
ATown25
Back
Top