Seating die designs

[DShortt]

Why are seating dies not designed to contact the bullet based on the ogive called out for that caliber?

Instead we've got this weird crap going on where the seating stem is pressing on the nose somewhere.....

 

[hoz53]

Why are seating dies not designed to contact the bullet based on the ogive called out for that caliber?

Instead we've got this weird crap going on where the seating stem is pressing on the nose somewhere.....

thanks for reminding me- i need to get some stems--

 

[WSnyder]

Why are seating dies not designed to contact the bullet based on the ogive called out for that caliber?

Many years ago I tried to get the machinist that made the Hoover tipping dies to make one. Mic McPherson suggested one years ago and I presented that to the machinist as a new product but it got shrugged off. The prototype is based on a Redding Comp Bushing sizing die but with an insert matched or machined with a chamber reamer or throating reamer matching your throat. I messed with it a little but put it aside years ago saying I'll get back to it but haven't.

 

[David Christian]

Only 2 calibers available now, but I have been using the 7mm for 3 years now and they work great.

Arbor Press Seating Stem Upgrade

fclassproducts.com

Vld, non-vld, and Blake stem.

 

[DShortt]

I mean..... I fail to understand why that wouldn't be a basic design implementation.

Basically a hollow tube of the correct ogive diameter. If your bullet is getting deformed seating it then I'd suspect other problems. Cast bullet shooters might need special considerations if it's really soft lead but probably not if their cases are properly prepped. And copper jacketed? Deformed by a seating die on the ogive?

 

[WSnyder]

Only 2 calibers available now, but I have been using the 7mm for 3 years now and they work great.

They still don't look like they come anywhere near where the lands actually touch the ogive or do they?

 

[WSnyder]

Basically a hollow tube of the correct ogive diameter.

The problem with the smaller OD stems is when you get them close enough to the actual land touch point is they want to crack and split because they become too thin.

 

[DShortt]

The problem with the smaller OD stems is when you get them close enough to the actual land touch point is they want to crack and split because they become too thin.

So.....
It's not possible to design dies with a larger diameter seating stem in the die body? I'm not talking about making the seating stem thin. Just making the seating stem contact the bullet at the ogive.

This can't be that hard. Just a different way of thinking.

 

[BoydAllen]

So.....
It's not possible to design dies with a larger diameter seating stem on the die body?

There has been one seater that was (is?) built that way. The problem comes when a FB bullet is used. As the bullet and case rise into the die, the base of a FB bullet can move outside of the case mouth, jamming up the seating, and with enough force deforming the case neck. You would need a slightly over bullet diameter ring between the top of the case and the seater stem's lowest possible position, and that would be complicated to machine as a one piece die body.

 

[DShortt]

So why not slightly bell the case mouth like cast bullet shooters do? Boat tail moulds and cast bullets don't work well together.

 

[ORjeff]

I agree with the OP that this is the best approach and I have patented a seater die that does this. superior-precision.com

 

[David Christian]

They still don't look like they come anywhere near where the lands actually touch the

They still don't look like they come anywhere near where the lands actually touch the ogive or do they?

Correct review, yet the underlying assumption posed is that you need to be as close to the pressure ring as possible. Having used the Blake stem for several years now, my experience has shown this seater to be extremely consistent, bullet after bullet. That tells me the assumption may not be correct.

 

[WSnyder]

It's not possible to design dies with a larger diameter seating stem in the die body? I'm not talking about making the seating stem thin. Just making the seating stem contact the bullet at the ogive.

This is what I described with the Mcpherson/Redding bushing die concept. A larger diameter seating stem (the bushing) with the proper internal profile. The bushing is relieved to clear the case neck so it can come down far enough to contact the land touch point.

 

[DShortt]

Correct review, yet the underlying assumption posed is that you need to be as close to the pressure ring as possible. Having used the Blake stem for several years now, my experience has shown this seater to be extremely consistent, bullet after bullet. That tells me the assumption may not be correct.

Sending a PM. Perhaps someone already addressed this and I just haven't seen it.

 

[WSnyder]

I agree with the OP that this is the best approach and I have patented a seater die that does this. superior-precision.com

I think I see what you did there. I will study it more.

 

[DShortt]

This is what I described with the Mcpherson/Redding bushing die concept. A larger diameter seating stem (the bushing) with the proper internal profile. The bushing is relieved to clear the case neck so it can come down far enough to contact the land touch point.

PM sent

 

[ELR LVR]

There are different stems for different shaped ogives such as VLD stems
I have drilled a center hole in one of my seating stems to prevent it touching the tip
The rest of my dies such as RCBS/Redding the bullet tip/Meplat does not make any contact inside the stem
As far as just touching the ogive....I think it is better to have the stem contacting more surface area length wise
rather than one circular portion such as a cross section of a bullet to prevent deformation.
What some guys have done is....drill the stem out larger, or make one if you have a lathe , brass works
Place epoxy in the stem and insert bullet so the seater stem is the exact same shape as the ogive of the bullet
---
Why they dont contact or reference where the bullet touches the lands?
Good question but it could be because it is too close to possibly skipping over the bullet if it deforms
(Swaging it down)
this cannot happen if the contact surface area is further up the tip

 

[FTR_Mojo]

Isn't this what the SAC seating die does? You select the stem that fits your bullet.

 

[boltfluter]

On a Wilson die, I believe having the stem very close to bullet diameter also helps guide the bullet straight into the case. Not sure if a bigger stem diameter would have a big enough advantage to offset the lost bullet guidance? Interesting discussion though.
Paul

 

[AlNyhus]

On a Wilson die, I believe having the stem very close to bullet diameter also helps guide the bullet straight into the case. Not sure if a bigger stem diameter would have a big enough advantage to offset the lost bullet guidance? Interesting discussion though.
Paul

I agree, Paul...there's a reason the Wison stems are sized that way.

Making sure the bullet nose doesn’t bottom in the stem is basic stuff and easily rectified. Lapping the stem to the bullet increases the contact area. Again, a simple thing to do.

Good shootin' -Al