Micrometer seating die problem

[ronsatspokane]

So I've got a problem with a Wilson micrometer seating die in 6.5 PRC. I use there dies in other cartridges and I even had a 6.5 PRC die before and did not have a problem with it. They are great dies.

The problem with this one is that when you try to seat a bullet to a depth where the beginning of the bearing surface passes the neck/shoulder junction, the force required is extreme. As in, you will find yourself wondering if the K&M press is going to warp. It behaves like there is a doughnut formed in the brass and the die is cut so tight that the brass cannot expand. There is no doughnut however, this is brand new never fired brass. The first brass I tried is Nosler, the second brass I tried is Lapua. Both brands had the problem.

I sent the die to Wilson and they said it was ok. I asked them if they felt extra pressure was required when the bearing surface crossed the neck/shoulder junction. They said yes but they did not see it as a problem. It is a big problem, the result is much higher neck tension that one could ordinarily achieve. The result of that is inconsistent groups. I had to revert to an old RCBS Micrometer seating die I had.

Has anyone else ran across this? Should I just stick the die in my lather and cut into that shoulder/neck junction?

 

[joshb]

This is why I always try to seat bullets above the junction. The shoulder acts like a buttress around the neck.

 

[JMayo]

Lube ?

 

[6BRA]

Donut?

 

[B y r o n]

Are you compressing the powder?

 

[Tod Hendricks]

I‘ve had the stem expand to an interference fit when seating pressure is high. Try sanding the outside of the stem where it contacts the bullet, and roll up some sand paper and polish the hole where the stem rides, start with fine grit for both. Apply a light amount of lube on the stem.

 

[rjs1230]

I would try running a mandrel through the neck .

 

[CloudNein]

So going from brand new case to seating bullet, no redding dry neck lube, no expander mandrel?

Interestingly enough, Wilson does make a inside neck reamer, but only for fired brass.

I would still start with an expander mandrel (with above lube) on new brass, before I started machining and making irrevocable changes. This is generally advised by manufacturers. Never had an issue with my Wilson .223 arbor seating die using this method.

 

[Chris Edmondson]

I use the same die (LE Wilson), I wonder if the seating stem itself is getting hung up somewhere?

Will the stem go all the way in without any bullet or case involved?

If I had another stem laying around I'd see if it will seat a bullet, never mind not proper to caliber. You can also run a pin gage in the die to rule out something jamming.

 

[6BRA]

More about the resize die?
Did you turn necks?How many passes to turn? How many passes through resizer? Resizing operation causes donuts. Did you pin guage the neck? Tight fitting pin guage pass the the shoulder neck junction. Brass doesn't have to be fired to have a donut. More about the bullet? Most 6mm boat tails will mic .2434 to 2437. I can't imagine bending an arbor press to seat a bullet. Even with a donut.

 

[ronsatspokane]

This is why I always try to seat bullets above the junction. The shoulder acts like a buttress around the neck.

So do I in most instances. I'll even open up the throat with a unithroater to get that extra length but I'm doing seating depth tests.

 

[ronsatspokane]

Lube ?

No neck lube. It seats fine until hits the junction.

 

[ronsatspokane]

Donut?

Only if Nosler and Lapua are shipping brass with a doughnut built in. It is virgin brass.

 

[ronsatspokane]

Are you compressing the powder?

No. And a compressed load would not require the kind of force I'm talking about.

 

[ronsatspokane]

I‘ve had the stem expand to an interference fit when seating pressure is high. Try sanding the outside of the stem where it contacts the bullet, and roll up some sand paper and polish the hole where the stem rides, start with fine grit for both. Apply a light amount of lube on the stem.

The stem is too small of a diameter to interfere and I'd need to be seating that bullet past the bearing surface for it to enter the neck. That put the bullet floating in powder. But since it's your recommendation I'll pull the dial calipers out and make sure. The indentation on the bullet is not far below the tip and the bullet goes in fine until it huts that junction. At that point it's like a cold stop that requires a lot of force to get past. Enough force to deform the bullet.

 

[ronsatspokane]

I would try running a mandrel through the neck .

I full length size the brass and then run it over the Wilson mandrel. Like I said, seating is nice until you hit that junction.

 

[ronsatspokane]

So going from brand new case to seating bullet, no redding dry neck lube, no expander mandrel?

Interestingly enough, Wilson does make a inside neck reamer, but only for fired brass.

I would still start with an expander mandrel (with above lube) on new brass, before I started machining and making irrevocable changes. This is generally advised by manufacturers. Never had an issue with my Wilson .223 arbor seating die using this method.

Per Tods suggestion I'm going to look closer at that.

 

[ronsatspokane]

More about the resize die?
Did you turn necks?How many passes to turn? How many passes through resizer? Resizing operation causes donuts. Did you pin guage the neck? Tight fitting pin guage pass the the shoulder neck junction. Brass doesn't have to be fired to have a donut. More about the bullet? Most 6mm boat tails will mic .2434 to 2437. I can't imagine bending an arbor press to seat a bullet. Even with a donut.

I've tried two. A standard RCBS and a Forester bushing die. When done they get pushed over the Wilson mandrel.

 

[ronsatspokane]

Sorry for the late replies. I caught a bug and I've been either staring at my feet or swallowing my tongue for a week.

It behaves as if all the brass comes with a built-in doughnut. That would tell me that the seating die is cut too tight. The last one I had did not have this problem and none of the other calibers I have in their seating dies have this problem. Their dies are very nice and I like the concentricity they provide but I don't think they need to be that tight at the neck/shoulder junction. It seems that just holding the majority of the shoulder would keep it centered and still provide the concentricity.

Thanks for the replies.

 

[ronsatspokane]

Oh, and I ended up neck turning the Nosler brass. Had the same problem only fewer instances of the problem. Then I went to the Lapua brass and it had the same problem. I sat back, pulled at my beard and said something not repeatable in polite company. Something like WTF. Yeah, you guys don't qualify as polite company. Well educated company maybe but far from polite.