K&M Arbor Press with Standard Force Pack

[Papa Charlie]

I want to upgrade my seating process to include a Wilson seating die and an arbor press. I was looking and found the K&M press that uses a standard dial indicator to read force (0.001" equates to 1lb of force). The press sells for what seems like a reasonable price of $149.99 at MidwayUSA.

https://www.midwayusa.com/product/556461/k-and-m-arbor-press-with-standard-force-pack

I was wondering if anyone is using one of these and what your opinion is?

 

[Mulligan]

It’s a thing of beauty!

exactly what I use for both my F-class rifles
CW

 

[Nick_Mansfield]

Bruno’s has them cheaper if I’m not mistaken...great little press.

 

[Papa Charlie]

Do you use the standard force pack (0-150lb) or the low force pack (0-40lb)?

 

[rardoin]

Do you use the standard force pack (0-150lb) or the low force pack (0-40lb)?

I have a K&M in addition to a unit that measures via hydraulic force transfer. They both work equally well IMO. If I had neither and had to make a purchase based on the knowledge I have now I would buy the K&M because it is simpler (almost unbreakable) and cheaper. If you are using neck tension (or if you Guffites would indulge...neck intereference or bullet hold...which I am not in the favor of having as much as I can get) of at/under 0.0015 the lighter force pack would likely work but loading 6.5mm rounds with over 0.0015" 'neck tension' would top the light force pack gauge for me; I went with the heavier one. With 6mm rounds and under with light neck tension the 0-40lb would likely be fine.

 

[Mulligan]

Do you use the standard force pack (0-150lb) or the low force pack (0-40lb)?

I use the standard
CW

 

[hrlincoln]

Do you use the standard force pack (0-150lb) or the low force pack (0-40lb)?

I use mine with the standard force pack and dial indicator...not sure if .001" really equals 1lb of pressure as they claim, but the setup does give you a pretty good indication of whether your bullet seating force, and hence neck prep process is fairly consistent.

 

[Papa Charlie]

I am reloading .308 Winchesters, un-turned necks. Try to keep the neck tension around 0.0015" to 0.002".
I think the standard might be the better starting point. I guess I can always purchase the Light Force Pack later if I need it.

 

[hrlincoln]

I think the standard might be the better starting point. I guess I can always purchase the Light Force Pack later if I need it.

I agree...and I think the standard may be all you'll ever need.

 

[Mulligan]

@Papa Charlie
In my opinion,
The real value is being able to sort out what makes a difference in the loading room and then testing it to see how it effects the target.

Just having a simple repeatable way to measure the force required to seat bullets provided a way to prove to myself what is a valuable step or process and what is not.
CW

 

[zipollini]

I've used the K&M and the 21st Century hydro press. I like the 21st Century waaaaaaay more.

 

[rardoin]

.....not sure if .001" really equals 1lb of pressure as they claim.....

It does correlate very tightly with my hydraulic base (used on a K&M press). However, it is just giving you a number...it is a comparison to other seatings so you can change methods of case prep to attempt for more consistency and to cull or sort cartridges based on relative seating pressures.

 

[Hunter2678]

I've used the K&M and the 21st Century hydro press. I like the 21st Century waaaaaaay more.

ill second that...

 

[LRPV]

I've used the K&M and the 21st Century hydro press. I like the 21st Century waaaaaaay more.

I have used them both and by far prefer the K&M. It's the one I started with and maybe that's why I like it better. I guess that's why they still make both.

 

[jlow]

I've used one for many years (standard). It is an excellent way to help you figure out how to get consistent neck tension. Once you figure that out, you really only need it for occasional QC. I see no need for the hydro version as it is significantly more expensive and more things to break. It's a solution looking for a problem that the K&M already fixed.

 

[dkhunt14]

It does correlate very tightly with my hydraulic base (used on a K&M press). However, it is just giving you a number...it is a comparison to other seatings so you can change methods of case prep to attempt for more consistency and to cull or sort cartridges based on relative seating pressures.

We tested both the 21st Century hydraulic and the K&M. We used a load cell and both were pretty much were very close to be actual pounds. They were within one pound of each other. Matt

 

[David Christian]

K&M vs. 21st Century? What if I asked a different question? Does seating force translate to anything on target or muzzle velocity? I conducted the following test and am left feeling like seating force does not translate to muzzle velocity. I would love to see someone do a similar empirical test measuring impact on the target. When I find time in my calendar I will reproduce this test and measure bullet impact on target.

I loaded up 80 rounds in the exact same process. Lapua brass, Berger bullets, AMP anneal each firing, wilson seater die, etc. I then measured each seating force using the K&M arbor press. To capture the pressure I would pull down on the arbor and then slowly stop 1/16" before it would bottom out, then read the measurement on the dial. Very repeatable measurement. I then fired each round at pace with my magneto speed to capture FPS data. I then did a regression analysis in excel and generated the following (truncated for visual):



I am not a scientist by trade, so I am completely open to suggestions on how to produce a better set of empirical data. Please share with me a different result from empirical data. To date, I have not seen any test result, yet have heard a bunch of conjecture.

Best,
DC

 

[dkhunt14]

K&M vs. 21st Century? What if I asked a different question? Does seating force translate to anything on target or muzzle velocity? I conducted the following test and am left feeling like seating force does not translate to muzzle velocity. I would love to see someone do a similar empirical test measuring impact on the target. When I find time in my calendar I will reproduce this test and measure bullet impact on target.

I loaded up 80 rounds in the exact same process. Lapua brass, Berger bullets, AMP anneal each firing, wilson seater die, etc. I then measured each seating force using the K&M arbor press. To capture the pressure I would pull down on the arbor and then slowly stop 1/16" before it would bottom out, then read the measurement on the dial. Very repeatable measurement. I then fired each round at pace with my magneto speed to capture FPS data. I then did a regression analysis in excel and generated the following (truncated for visual):
View attachment 1073892

View attachment 1073893
I am not a scientist by trade, so I am completely open to suggestions on how to produce a better set of empirical data. Please share with me a different result from empirical data. To date, I have not seen any test result, yet have heard a bunch of conjecture.

Best,
DC

Maybe it's like changing a bushing when sizing cases. It doesn't show up much on a chronograph but does on target, especially at distance. This is another reason I don't rely on a chronograph for loads. I trust what the target tells me. The only time I use a chronograph is to get a velocity for drops. It Matt

 

[Papa Charlie]

I shoot with some very good competitors, I am working on it, they tell me that they see the difference on paper. By grouping rounds based on seating pressure in 10lb increments they are also able to reduce the ES considerably.

I just placed my order for the K&M with Std Force Pack and a Wilson Micrometer seating die. I am not expecting huge benefits but if this can help me improve my score then it will be worth it, as much as anything we spend money on in this game.

I have shot some 200 scores, but it seems, at least for me, that it always boils down to 1 or 2 shots during a relay that kills my score. Not by a lot, but drop one point and there goes the 200 score. More over, if it can help me pull a few more of the 10's into the X then even better. The best I have done is 16X so far.

We will see if this makes a difference. I hope so.

 

[oldduc]

I shoot with some very good competitors, I am working on it, they tell me that they see the difference on paper. By grouping rounds based on seating pressure in 10lb increments they are also able to reduce the ES considerably.

I just placed my order for the K&M with Std Force Pack and a Wilson Micrometer seating die. I am not expecting huge benefits but if this can help me improve my score then it will be worth it, as much as anything we spend money on in this game.

I have shot some 200 scores, but it seems, at least for me, that it always boils down to 1 or 2 shots during a relay that kills my score. Not by a lot, but drop one point and there goes the 200 score. More over, if it can help me pull a few more of the 10's into the X then even better. The best I have done is 16X so far.

We will see if this makes a difference. I hope so.

I have found that if I hold my mouth just right and throw some salt over my left shoulder and rub my rabbits foot just before I pull the trigger, I am much more likely to hit that X.
~Gary