Issue seating bullets


April 9, 2010, 10:31 PM
I've been reloading for a couple years now with the RCBS Pardner Press kit. I've added a few items along the way and it has done well for me. I load .357mag, .30WCF, and 7.62x54r with it.
I load for plinking mostly but lately I've gotten a touch serious about better accuracy with the x54r specifically. I bought 100 Lapua cases the other day from PV that I intend to use in club competition (Mil bolt rifle as issued - range 100 yards). I've been using PRVI cases which have worked well.

Anyway, cut to the chase, tonight I loaded up 10 rounds for testing tomorrow morning. I noticed that after seating the bullets (150gr Sierra ProHunters (.311)), that they did not go in centered. As in there is a slight bulge on one side of the neck and not on the other. This got me thinking that maybe my press is at fault because I've noticed when I use the Lee factory crimp die, as the tip of the round shows coming thru the opening in th top of the die, it always seems to push slighty to the side at the top of the stroke.

I know this is not a positive for accuracy. Is it time to move up a notch from the Pardner Press to something better, or am I looking at this wrong?

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April 10, 2010, 08:57 AM
You should be able to roll your rounds on a flat surface to see if the bullet is centered or not. A mirror works well for this. This condition you describe is a bit strange. I would look at a fired case(out of this rifle) before sizing to see if it has the bulge. Then I would follow up by checking each step as you size the case and seat the bullet to determine at what step the bulge is introduced.

It is possible that the ram is off center on your press, but all rounds loaded would be affected by this.

You may want to put a case in the shell holder and raise the ram (with out a die in the press) and watch as the case rises, you should be able to see if the ram is off center. You'll have to be straight up over the press, looking down through the die hole to see that though.

It is possible that your die is off center also, this would affect only the rounds loaded with those dies.

The only other thing I could think of is that the brass has a weak side to it and is letting the expander ball open one side of the neck more than the other. Lapua is normally very good brass, so I would not think that would be the problem.

What brand-kind of sizing die are you using? Photo of the round?

I'm just throwing out some wild guess as what would cause that condition.

Jimmy K

April 10, 2010, 09:22 AM
It's more likely that the die is not centered to the ram. I always run a case up into the die before I lock it down, this self-centers the die and seems to correct for any possible misalignment.

Lots of people scoff at the idea of rolling a case over a mirror to look for runout but it works surprisingly well. Your eyeball can detect a very small offset of the bullet to the case when it is rolling, especially right at the tip of the bullet.

April 10, 2010, 09:22 AM
Neither the press or seater die can cause that effect.

What you're seeing is weak places in the case necks that give way. It's especially common when the sizer /expander leaves too much "tension" for seating the bullet. For the type matches you will be shooting it's unlikey to have much effect.

If the concentricity is truly horrible it can be seen by rolling a cartridge but run-out is rarely that bad.

April 10, 2010, 09:26 AM
I disagree, I can make that kind of misalignment with my 45-70 loads, and I can correct for it. If the neck thickness of the brass is grossly off one side to the other I can see where that could happen but they have to be pretty big differences.

April 10, 2010, 09:33 AM
ranger - are you asserting he's oversizing the neck? That would tend to enhance the problem.

April 10, 2010, 11:30 AM
I am using RCBS dies for the x54r.

This go around though the brass (Lapua) is brand new. I only ran the neck sizer into the the neck to correct random minor dents from shipping. After that I touched them up with the chamfering tool.

I shot the rounds this morning and as anticipated they did poorly. This same load last weekend shot a 1-3/16 inch group of 5. BUT, those were PRVI cases that had been fire formed and neck sized. These were new unfired Lapua cases and I'm sure that is throwing things off as well.

The rounds not seating concentrically is my main concern here. Lapua is top notch so I don't think its the brass. Has to be me.

The next time it happens I will post pics.

I do not understand when you say you can correct this by running the case into the die before locking it down. Could you elaborate on that point?

April 10, 2010, 11:36 AM
The die and press threads have a lot of slop built into in them. They are loose & sloppy when screwing the die in & out by design for easy die changes.

If you just screw the die down and lock the lock ring, all the thread slop can go left, right, front, back, or stay perfectly centered.

Most likely, it won't do that though.

If you leave the lock ring loose and run the case up in the die, the die threads will self-center on the press threads, and stay centered when you tighten the lock-ring.


April 10, 2010, 11:52 AM
yep, that's a good description. it can account for more error than you might think.

April 10, 2010, 11:56 AM
OK rc I think I'm following you here.

Run the die into the press to the lock ring. Then run empty case up inside. Tighten the lock ring with the case inside.

Is this a prefered move with all dies? FL, neck, seater die, factory crimp?

Thank you for the insight. Seems I've been running partially blind for some time now.

April 10, 2010, 11:57 AM
The neck wall thickness may be different between the 2 brands of brass. Take a loaded round of each brass, measure the diameter of the necks. The Lapua is thicker/larger i would guess? Are you using the correct expander button for a .311" bullet?

April 10, 2010, 12:00 PM
Is this a prefered move with all dies? FL, neck, seater die, factory crimp?I try to do it with all dies as much as possible.

Run the die into the press to the lock ring.Actually, back the lock-ring clear off so it is not in contact with the press thread flat at all.
Once the die is where you want it, tighten the lock-ring down.


April 10, 2010, 12:03 PM
The seating stem must fit the bullet ogive correctly for good alignment when seating.

April 10, 2010, 12:41 PM
I only ran the neck sizer into the the neck to correct random minor dents from shipping. Use the expander ball correctly while sizing the neck. The bullet should not act as an expander.

April 10, 2010, 01:54 PM
243 you have hit on an important point for my situation.

The Lapua brass appears to be sized from the factory for .308 bullets. PRVI comes set to the larger .311 diameter.

So, I will be needing to neck size all of this brass to accept my larger diameter rounds.

...would neck sizing be appropriate here or should I go with an initial full length? These cases are way under the 2.105" trim to length spec. for the x54r round.

Steve C
April 10, 2010, 02:32 PM
I've usually attributed problems like this to the bullet nose fit in the seating stem not matching up enough to hold the bullet from canting in the seating die. My fix for this has been to start the bullet part way, back out a bit and rotate the cae 180% in the shell holder and complete the seating. This seems to allow the alignment to correct itself as the pullet is pushed the other way for the second half of the seating process and centers it properly.

April 10, 2010, 03:40 PM
That sounds reasonable, Steve C.

Thank you for the assistance/input.

April 10, 2010, 04:07 PM
...would neck sizing be appropriate here or should I go with an initial full length? These cases are way under the 2.105" trim to length spec. for the x54r round I would full length resize the new brass.

April 10, 2010, 06:31 PM
That just one of the reasons that I use a Forster CoAx press... floating die alignment.

I was still asleep when I answered with my guess this morning and some missing info that would have helped.

I believe that 243 & Stevec has the correct answer concerning the case neck inside diameter and bullet size. I thought you were expanding to the correct neck size.

Jimmy K

April 10, 2010, 07:39 PM
Since I started reloading the x54r I've used either PRVI factory ammo, and reloaded the used brass, or I've bought new PRVI cases. Both instances the cases are .311 dia ready. I've been experimenting with this caliber for quite awhile and like most things I've fallen into a routine.

Never gave a thought to the Lapua cases having the smaller diameter neck.

That floating CoAx press sounds interesting.

April 11, 2010, 07:16 AM
You should give it a good look if you are shooting for accuracy.

Jimmy K

April 17, 2010, 12:36 PM
So I've been eyeballing the CoAx and I have a question. Will I be able to use my x54r RCBS dies in this thing? Will I need some Forster "extras" to make this happen?

Or do you have to use Forster dies?

April 17, 2010, 12:42 PM
You can use any dies. But it won't cure your bullet seating issue. Plus, swapping the shell-holder jaws is a pain.

April 17, 2010, 02:44 PM
Some Benchrest shooters use the Partner press. See link and photos here > They do use Redding Competition dies or custom dies, might make a difference? :confused: I did replace a very old RCBS Rock Chucker, the ram would fall forward a few thousandths at the top of the stroke when seating bullets. Having never checked run out, not sure if it was a problem or not using standard RCBS seating dies. Groups remained good. :)RCBS gave me a new press for the price of shipping after using it for 25 years, what a great company:)

April 17, 2010, 04:08 PM
Swapping shell-holder jaws is no more trouble than any other adjustments in reloading. You just have to know how to do it.

The CoAx will not solve your problem if you have faulty dies or weak sided case or if you over sizing your brass. No press will do that, not even a Lee.

You can use any die that has 7/8"x14 tpi.

No you don't need anything other than full size die lock rings(round, no hex shaped), the Forster and Lyman work best, but I have a mix of almost every brand made except Lee.

Did you read the Forster link I sent you?

Jimmy k

April 17, 2010, 04:36 PM
Yes I did, just double checking here. The CoAx looks like a good solid piece.

Also made up 50 rounds the other day and used Steve C's suggestion of rotating case 180 degree 1/2 way thru the seating process. Have to say that it worked quite well. No bulging case necks this time around. But then I was using my fire formed PRVI cases.

Was thinking I would hold off sizing the Lapua cases until I further researched the Forster product. Lapua cases are double the cost of the Partizan and I don't want to goob them up.

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