Force Indicating Seater For Standard Presses - Would This Work?

[Wheres-Waldo]

Looking for a means to read comparative force during bullet seating, without having to move everything to an arbor press.

Would the ability to clamp a female 1/4” drive near the fulcrum of the press handle and affixing a dial torque wrench w/ memory indicator to be used as the handle during seating be a method you’d think is worth trying?

Not looking to discuss the viability of measuring seating force here... Only whether this would be a sensical way to measure the force applied?

 

[918v]

The problem with force measurement while seating projectiles is once you reach a predetermined seating depth the seating die bottoms out and force goes through the roof. You have to consciously watch yourself and the gauge to see what the final number was.

In theory, your device would work but with the compound leverage of the press you’d break the torque wrench pretty quick.

Arbor presses don’t have any leverage in comparison. They are a better device for force measurement.

 

[Wheres-Waldo]

The problem with force measurement while seating projectiles is once you reach a predetermined seating depth the seating die bottoms out and force goes through the roof. You have to consciously watch yourself and the gauge to see what the final number was.

In theory, your device would work but with the compound leverage of the press you’d break the torque wrench pretty quick.

Arbor presses don’t have any leverage in comparison. They are a better device for force measurement.

918,

While you sound spot on here, would a sleeve style die like a Redding or Forster Ultra-Mic, where the ram and die do not bottom out, prevent this issue?

 

[918v]

No because something has to come to a hard stop, either the die or the press in order to seat the bullet to a consistent depth.

 

[wadebrown]

if you measure the force the cartridge base applies to the force transducer will not go up when the press bottoms out. The problem I see with just measuring force is the force measured will be dependent upon the force you apply to the press handle. I have a force tranducer and linear scale, I bought them with the intent building a system that will measure force and position of the bullet. My thought is to have the software would sort seating force from high to low and have the shooter shoot the rounds in that order.

My thoughts are that if seating force effects POI, nuzzle velocity, etc, ordeing the shooting would reduce the difference in seating force from shot to shot. I mainly shoot F-class so a gradual shift in POI can be adjusted for because you know where each bullet hits the target.

wade

 

[918v]

But the OP is talking about having the force measurement in the press handle, not at the cartridge base.

 

[wadebrown]

But the OP is talking about having the force measurement in the press handle, not at the cartridge base.

I understand that I was giving a method that does not cause the spike in force when seater bottoms out.

 

[Wheres-Waldo]

Wade,

Have you come to any personal conclusion on a link between seating force and external ballistics?

If so, could you quantify it?

 

[Dthomas3523]

It’s pretty easy to buy a hydro or k&m press. Probably much easier than attempting to design something that likely won’t work.

Also, I find that the dial on my hydro press is more of a QC check and 99% of the time with proper brass prep I don’t see much variance in the seating pressure.

If you are tedious about your brass prep and use mandrels to finish sizing, pin gauge to spot check neck tension, and some sort of neck lube when seating to keep friction fairly consistent, the arbor press is really just a confirmation of your brass prep. It’s not necessarily needed if you prep brass well.

And if you don’t like putting a lot of effort in brass prep, a gauge is just gonna drive you nuts when it’s 20 on one bullet and 60 on the next.

 

[wadebrown]

Wade,

Have you come to any personal conclusion on a link between seating force and external ballistics?

If so, could you quantify it?

No, i have not that is one of the main reason for building the system I have the components. I did not make any claims that seating force would impact POI but if it did it seems that ranking the rounds would help.

wade

 

[Dthomas3523]

Wade,

Have you come to any personal conclusion on a link between seating force and external ballistics?

If so, could you quantify it?

In my short time measuring seating force, it’s not the actual force that will have an impact on POI, but the inconsistency of seating force from one round to another that will.

I can be seating rounds at say 40 psi average with maybe 10psi ES. When I see something like a 20psi seating pressure or 60psi, I can mark those rounds and set them off to the side.

In experiments at the range, I will have a very low/consistent ES in velocity with the rounds that had the consistent pressure. I can then throw one of the marked rounds in and it will consistently throw off my ES by a noticeable amount. The further out to distance I shoot, the more that ES matters. So it can start throwing off POI to a detrimental amount past a certain distance.

The difference in the pressure is mainly a product of something being off in the brass prep. Be it the neck tension or friction inside of the case neck.