Haydon vs K&M arbor presses with force measurements

[BradY]

Hi all

I have the opportunity to purchase a K&M arbor press with force measurement or the haydons arbor press with force measurement. Im not too familiar with the haydons model and with them not available anymore for service/parts or a look at what it all looks like, Im a little hesitant. Saying that some people are telling me the K&M unit isnt all that good. Would be great to hear some feedback regarding the two.

 

[zipollini]

How bout this

http://www.21stcenturyshooting.com/Hydro_Bullet_Seater.php

Have gotten really good reviews.

Here is another I started recently

http://forum.accurateshooter.com/index.php?topic=3856405.0

 

[Ares]

The 21st century hydro bullet seater would be my recommandation.
It certainly is better then the K&M, the other one i can't comment on.

 

[suberjc]

Hi all

I have the opportunity to purchase a K&M arbor press with force measurement or the haydons arbor press with force measurement. Im not too familiar with the haydons model and with them not available anymore for service/parts or a look at what it all looks like, Im a little hesitant. Saying that some people are telling me the K&M unit isnt all that good. Would be great to hear some feedback regarding the two.

BY,
I use the K&M.
I'm not sure what the expectation is from folks who are dis-satisfied. It absolutely doesn't shout the inch/pounds at you when you've reached MAX, (The measurement is relative anyway) but it works as advertised. I've used mine exclusively for 4 years.
OK so you have to put one eye on the gauge and one eye on the top of the die so you'll know when it's down. It DOES slow things down a bit. You have to get accustomed to using it. Once you do you won't load without it. Sort them low to high, go out to 600 on a calm day and shoot them that way. If you yourself are having a calm day you'll be amazed how they print on the target.

 

[jlow]

I honestly don’t think there is any significant difference between the K&M and the 21Century. They are both measuring the same thing with the only difference being one is using a direct mechanical linkage and the other a hydraulic one. What does make the biggest difference is the user’s understanding of what to look for. Everyone that starts to use it gets confused in the beginning because they don’t know what to look for since there seems to be so much going on.

Here is a primer:

When you first pull down on the handle, you will feel an increase in pressure – at that point, nothing is really moving significantly as the bullet is pushing down on the case mouth and slowly widening it. That pressure will continue to increase until suddenly you will see it stop increasing even though you are still pulling down on the handle and it is still moving – this is the point when the mouth of the case open and the bullet is entering into the case mouth and this is the pressure value you need to take note of. After this, the bullet will seat fully and as you continue to pull on the handle, the pressure will rapidly rise to max because you are no longer seating the bullet but just pushing against the top of the seater which is steel and will not budge. This part you can also ignore.

That is it.

 

[chkunz]

I honestly don’t think there is any significant difference between the K&M and the 21Century. They are both measuring the same thing with the only difference being one is using a direct mechanical linkage and the other a hydraulic one. What does make the biggest difference is the user’s understanding of what to look for. Everyone that starts to use it gets confused in the beginning because they don’t know what to look for since there seems to be so much going on.

Here is a primer:

When you first pull down on the handle, you will feel an increase in pressure – at that point, nothing is really moving significantly as the bullet is pushing down on the case mouth and slowly widening it. That pressure will continue to increase until suddenly you will see it stop increasing even though you are still pulling down on the handle and it is still moving – this is the point when the mouth of the case open and the bullet is entering into the case mouth and this is the pressure value you need to take note of. After this, the bullet will seat fully and as you continue to pull on the handle, the pressure will rapidly rise to max because you are no longer seating the bullet but just pushing against the top of the seater which is steel and will not budge. This part you can also ignore.

That is it.

Do you think you are seeing the difference in static friction (before the bullet starts to move) and kinetic friction (after the bullet is moving) in this process?

 

[jlow]

I honestly don’t think there is any significant difference between the K&M and the 21Century. They are both measuring the same thing with the only difference being one is using a direct mechanical linkage and the other a hydraulic one. What does make the biggest difference is the user’s understanding of what to look for. Everyone that starts to use it gets confused in the beginning because they don’t know what to look for since there seems to be so much going on.

Here is a primer:

When you first pull down on the handle, you will feel an increase in pressure – at that point, nothing is really moving significantly as the bullet is pushing down on the case mouth and slowly widening it. That pressure will continue to increase until suddenly you will see it stop increasing even though you are still pulling down on the handle and it is still moving – this is the point when the mouth of the case open and the bullet is entering into the case mouth and this is the pressure value you need to take note of. After this, the bullet will seat fully and as you continue to pull on the handle, the pressure will rapidly rise to max because you are no longer seating the bullet but just pushing against the top of the seater which is steel and will not budge. This part you can also ignore.

That is it.

Do you think you are seeing the difference in static friction (before the bullet starts to move) and kinetic friction (after the bullet is moving) in this process?

How do you think one could differentiate between the two with these setup? I guess one can call the number you get just at the point when the bullet move into the neck as static friction and any changes as the bullet is moving through the neck as kinetic friction.

But generally speaking, this kinetic friction you are speaking of is always much less than the static friction or at least you hope it is and strive to make it so because if the kinetic friction is as much or more than the static friction, your neck would be very rough which is not what you want.

In my own experience, the gauge stays perfectly still as the bullet moves through and that is one way I can ID and get that number.

 

[jlow]

Had a request from another member for info as to how the dial indicator is attached to the press. Here is how mine is setup today when I used it. These indicators should be used with some pressure applied to them. For mine, the needle usually sit around 30 at rest, so I usually add about 70 to it which is around ¾ turn to bring it to “O” for use.

 

[chkunz]

I honestly don’t think there is any significant difference between the K&M and the 21Century. They are both measuring the same thing with the only difference being one is using a direct mechanical linkage and the other a hydraulic one. What does make the biggest difference is the user’s understanding of what to look for. Everyone that starts to use it gets confused in the beginning because they don’t know what to look for since there seems to be so much going on.

Here is a primer:

When you first pull down on the handle, you will feel an increase in pressure – at that point, nothing is really moving significantly as the bullet is pushing down on the case mouth and slowly widening it. That pressure will continue to increase until suddenly you will see it stop increasing even though you are still pulling down on the handle and it is still moving – this is the point when the mouth of the case open and the bullet is entering into the case mouth and this is the pressure value you need to take note of. After this, the bullet will seat fully and as you continue to pull on the handle, the pressure will rapidly rise to max because you are no longer seating the bullet but just pushing against the top of the seater which is steel and will not budge. This part you can also ignore.

That is it.

Do you think you are seeing the difference in static friction (before the bullet starts to move) and kinetic friction (after the bullet is moving) in this process?

How do you think one could differentiate between the two with these setup? I guess one can call the number you get just at the point when the bullet move into the neck as static friction and any changes as the bullet is moving through the neck as kinetic friction.

But generally speaking, this kinetic friction you are speaking of is always much less than the static friction or at least you hope it is and strive to make it so because if the kinetic friction is as much or more than the static friction, your neck would be very rough which is not what you want.

In my own experience, the gauge stays perfectly still as the bullet moves through and that is one way I can ID and get that number.

I have never used one of these gages but thought that maybe there would be a spike in force due to the static friction at first and then drop of as the bullet starts to move since kinetic friction is less than static friction. But based on what you say that is not the case. I was just thinking that could be the cause of some of the discussion as to the different readings that folks are seeing.

 

[mikecr]

jlow described readings well. I see the same.
You might also detect donut interference in seating.

 

[jlow]

I understand. It’s hard to absolutely know why people are having problems.

Speaking from my own experience, one big problem is the lack of instructions. When I first started using it, I was frankly at a loss. However, despite shelving it for a few weeks, I started using it and analyzing what I was seeing, then the whole thing became crystal clear.

Of course, if your “neck tension” is bad to start off with, you are going to see a lot of anomalies. For example, simple things like variable friction, burrs on the mouth of the case will cause you a lot of problem and these will superimpose on the actual real “neck tension” and make it impossible to get an accurate number.

mikecr is right about the donuts, those would be another monkey wrench in the works. I use a Lee Collet die as part of my final neck tension prep and that seems to take out any donuts.

 

[Chaotik]

jlow - Your primer made things quite clear.

Thank you.