Setting up the Forster Bench Rest Ultra Micrometer Seater Die

[Nissan_Ranger]

Hello, y'all,

I have a brand new Forster BR seater die.

The instructions direct that:
'With the press ram and shell holder at their highest points, screw the die in the press until the bottom of the sliding Die Chamber touches the shell holder. Continue screwing the die clockwise until you have fully compressed the sliding Die Chamber. Next, back it off at least one full turn because the Die Chamber should never be fully compressed when seating bullets.

That last sentence is causing doubt for me. Backing off the one full turn means that maximum lift of the casing is decided by the press ram. I see this as a source of inconsistency as play in the various connectors and lever pins would cause variations in ram lift height depending on how the lever is actuated. I contacted Forster support and they wrote back that the press ram action is what they want to see; they believe that works well enough.

So.... I checked the sliding chamber and it will lift another 1/8th of an inch past the bottom edge of the die housing, i.e., it is not 'fully compressed'...

With that in mind, I screwed in the die body (with the press ram and shell holder fully lifted) until the sliding die chamber was flush with the bottom of the die housing and the shell holder was in contact with the bottom of the die housing. I then turned the die three more full turns in so the press ram is way beyond where it can 'toggle over' and possibly cause damage. The handle of the Rock Chucker only goes to the horizontal and so there is no levering pressure worth speaking of when the shell holder meets the bottom of the die housing and I got very good 'feel' with some test rounds.

My reasoning is that contacting of the shell holder with the bottom of the die housing assures identical seating depth with each round rather than relying on the loosey-goosey action of the press ram alone.

Does anyone have any rational reason I should not depart from the original instruction and follow my observation on this?

Andy

 

[Wilbur]

I don't think it matters which way you do it. If you have the tools to measure, do it both ways and adopt either the better or the easier method. Measure from the base of the case to somewhere on the ogive of the bullet as there's some differences in how the tips form. Make the measurements with unprimed cases or make sure you don't have a primer that's not seated below the base surface.

 

[jackie schmidt]

I have always used Redding Dies, which work on the same principle as the Forster.

I seat the shell holder firmly against the die body to a ensure a positive stop, not relying on the presses linkage to achieve consistency. If the Sliding sleeve bottoms out before the shell holder contacts the die body, I chuck it up and face what ever it takes from the bottom of the sleeve.

 

[Boyd Allen]

A friend uses the Redding Competition seaters. I suggested a couple of things that seem to have improved their performance. The first one has already been discussed, adjusting the die body so that it contacts the shell holder. The other one is to slightly trim the bottom of the sliding sleeve so that the sleeve is pushed up by the case's shoulder instead of the shell holder. The last one depends on your case's fit in the bottom of the sleeve. If there is room, you can put a carefully installed layer of tape on the inside of the sleeve at the bottom (about 1/2" wide) to improve the fit of the case. All of these combined improved consistency of seating depth and concentricity of loaded rounds.

 

[jackie schmidt]

A friend uses the Redding Competition seaters. I suggested a couple of things that seem to have improved their performance. The first one has already been discussed, adjusting the die body so that it contacts the shell holder. The other one is to slightly trim the bottom of the sliding sleeve so that the sleeve is pushed up by the case's shoulder instead of the shell holder. The last one depends on your case's fit in the bottom of the sleeve. If there is room, you can put a carefully installed layer of tape on the inside of the sleeve at the bottom (about 1/2" wide) to improve the fit of the case. All of these combined improved consistency of seating depth and concentricity of loaded rounds.

Another thing that I have found when using these types of dies is avoid overly tight presses. Let the die do the work.

Think about what we are trying to accomplish when Loading. We want to size the case so it comes out of the die with correct dimensions, and truly straight. The we want to seat the bullet so that each young is truly straight and each bullet is seated to the exact same depth.

Anything that can interfere with this needs to be removed from the equation.


If anyone has ever seem my loading table set-up, you will notice the Partner Presses that appear to be totally worn out. There is a method to this madness. All the Press does is furnish the power to insert the case into the die and remove it.

The Dies do the work.