K&M Arbor Press

[chiefkerdog]

I was wondering how many are using the K&M arbor press with the force measurement and has it helped their shooting performance over any other type arbor press. Hoping for 600yd and 1000yd shooters to chime in with their experience.

 

[brian427cobra]

I have never used another press, I think my K&M arbor with seating force has made my ammo more consistent, but its hard to say if my shooting skills got better because of it.

 

[normmatzen]

I just started using one.
The first indication I got was far better SD's. I have been practicing with my magnetospeed and single digit SD's are the norm now. And I haven't really learned how to measure seating force well. I just put those that deviate the most from avg. static friction point into a separate group.
Of course, I could be getting better SD's because I am closely monitoring seating pressure!

And, yes, I am a 600 and 1000 yd shooter.

 

[Joe Maisto]

I have never used another press, I think my K&M arbor with seating force has made my ammo more consistent, but its hard to say if my shooting skills got better because of it.

K & M equipment is as good as it gets. I have seen all of Ken Merkels products and regret I didn't buy more of them , especially his primer seater.
He was a machinist with a better idea in many ways.

 

[jlow]

I just started using one.
The first indication I got was far better SD's. I have been practicing with my magnetospeed and single digit SD's are the norm now. And I haven't really learned how to measure seating force well. I just put those that deviate the most from avg. static friction point into a separate group.
Of course, I could be getting better SD's because I am closely monitoring seating pressure!

And, yes, I am a 600 and 1000 yd shooter.

Pretty much sums up my own experience when the press is teamed up with Wilson inline seating dies.

Also trying to learn how to measure seating force, the way I was using it was to note the pressure needed to start seating the bullet but if someone else has more tips, I am sure we would like to know.

 

[jlow]

I would love to read that lengthy post.

 

[NCVarhtr]

Yep, so would I and I suspect a lot of other readers....

 

[jlow]

I am interested in finding more about this.

So the Last 0.050” to 0.100” is the most important reading, the question is why?

I understand that the initial force reading would be what would be required for the boat tail to force open the case mouth, so that I think would relate to annealing condition of the brass (brass softness and spring back), the chamfer, and the internal diameter of the neck vs. bullet diameter, seems like those things would be important for neck tension. This is also the easiest part to measure as it is more abrupt. I think the biggest red herring here could be the chamfer.

The last length I think relates to overall grip of the bullet on its bearing surface which is affected by annealing condition, again internal diameter, and friction between the case and bullet surface. One problem with this is it is very difficult to measure as the movement of the bullet into the case is not always smooth and you are getting very close to that dead stop when the die bottoms out.

Getting the handle to move the same every time I agree is extremely difficult and I too have thought about a gizmo to turn the handle but…

Why is it a waste of time if the base or boat tail goes past the size part of the neck? Certainly, the bullet is no longer “blazing a path” but the neck tension effect of it moving down would in some way relates to what it experience moving up when it is fired? Also in some ways the "blazing a path" seems also artifactual like the chamfer.

Not challenging but just interested in understanding this better.

 

[doc gordon]

anybody make a kit for Sinclair arbor press to add gauge ?

 

[jlow]

I think Ken at K&M is the only one to offer the gauge and so you should just call him and ask.

 

[jlow]

Thanks! Nice and interesting read. I’ve thought of some of the same things mentioned in Larry Medler’s write-up. I’ve also talked to the builder of LoadForce-250 about his machine. IMHO, he had the right idea which is to capture the complete force over time which gives you the complete picture of the shape and forces involved. The only weakness of that device is that the seating is still done by hand and as a result the time sequence is not controlled and repeatable, this is where your original comment about the “gizmo to turn the handle” comes in.