For those with a AMP press

[rlporter507]

on your seating graph, which part do you feel is most important?
Initial smooth starting pressure, peak pressure, or final pressure?
my starting pressure has a glitch where the bullet enters, but a steeper chamfer smooths that out, but then that raises peak and final pressure.
using a vld champher has the hiccup when the bullet enters, but peak and final pressure is lower.
my peak pressure is between 15-20, and my final pressure is less than 10.
Ive been trying different things to get my graph tighter.
thanks

 

[RegionRat]

on your seating graph, which part do you feel is most important?
Initial smooth starting pressure, peak pressure, or final pressure?

The whole point to the analog graph, is to get control of each part of the graph.

So, not only is each part important, but getting the whole batch as identical as possible is also very important.

my peak pressure is between 15-20, and my final pressure is less than 10.

Sounds like you are playing with the very low end of seating forces.

In many circles those levels are for games like short range BR where the rounds are seated minutes before use and only moved from the loading bench to the firing line benches.

It would be risky to transport these levels or to magazine feed them, for example. That is not to say there is anything wrong with such low levels, but to point out that they are very fragile.

Ive been trying different things to get my graph tighter.

Yes, this is one of the keys without a doubt. It may not be obvious to all games, but when you are trying to shoot small or shoot far, it is very important.

It is also important to take your time and explore the effects of that average seating force on the target performance. Sometimes, the target doesn't care, but sometimes it can be very important.

So, intentionally swinging the seating force (neck tension) very wide to see the effects on the target are very important.

I tend to want the highest seating forces that don't ruin the target performance, but that is for pre-loaded ammo and magazine fed ammo. I'll go down to the 30 - 40 lbs force range for midrange ammo that I single feed and have to preload and transport. Any lower than that is too delicate for my life. YMMV

 

[Benchrest Braxton]

i just like seeing them have the same general curve. then ill set the high and low seating pressures aside.

dont overthink it too much. its a fantastic diagnostic tool to find outliers and inconsistencies and also automate your seating process!!!

 

[mdftr]

So interestingly, i think there's a couple of different ways of actually analyzing it from a numerical perspective - but whether you can actually infer anything from it, I'm not sure yet.

I built some tooling that allows me to detect outliers from a few different perspectives.

There's also a couple of different ways to represent the data - eg by looking at peak force (or...
Z-score, IQR, curve similarity methods, SPC charts, CUSUM, Nelson rule violations, UCL/LCL). But, you get to a point where this amount of interpretation isn't actually understandable and it's not useful!


Like others have mentioned - I've been using this for "consistency" of batches.

 

[Jager]

Like @RegionRat says, you want the entire graph as tight as possible. Any portion of any round that strays from the rest is a potential problem.

Here's a graph of 51 rounds. There was one obvious outlier at the bottom of the graph; and a couple at the top; along with a handful of less obvious ones. In all, eight were set aside as foulers.

 

[rlporter507]

thanks for the input, I mislead in my OP, my peak range is 10-15, actually in the 40,s and my final range is less than 10. I do have plenty of neck tension. My peak pressures is what im trying to get tighter, as tight as my final pressures.
I have more playing to do, then look at the target.
Ive loaded 600 rounds this week, and its funny one box will have only a couple i cull out, and another will have 5 to 10. same lots of brass, bullets and all. I do anneal, so the inside necks should be fairly clean, but I suspect there is a trace of carbon that hangs up the bullet even after brushing the inside neck. I agree, its a great tool to actually see what a change in the process does.

 

[GetReal]

Im not as technical as all that graphing... just sort of a seat of the pants consistency of initial pressure to expand the neck and then all the way to final seating being lesser pressure but again consistent. I cant really sense any final pressure

Then again, Im happy hitting a 12" square at 1000.

I guess my point is for those with out an amp press ( not newb but an an amateur like me) you really should get one so you can feel the difference because these long lever presses hide and obscure what is a really important part of loading for precision.

 

[fatelvis]

Do any of you guys use dual chamfers for the case mouth using both 45* and VLD angles? I read somewhere that doing such helped someone's consistency.

 

[RustyInBend]

I'm looking primarily at three things ... (1) overall seating force, (2) outliers to remove from the ladder or group shoot and relegate them to "Barrel Warmer" status, and (3) the initial seating force that I like to see around the 30's that tells me my neck tension is dialed in well.

Below is a good example of what I like to see, and how I use it. For (1) ... I see that the curve is consistent and the peak and end-state are tightly grouped. For (2) ... I see three "Outliers" that I remove from the equation and use them as barrel warmers. For (3) ... I see the vast majority around 30'ish which tells me my neck tension is right on target.

 

[PatMiles]

Timely post here, my Amp press is supposed to be delivered today.

 

[PatMiles]

Do any of you guys use dual chamfers for the case mouth using both 45* and VLD angles? I read somewhere that doing such helped someone's consistency.

For what it's worth I don't see any value doing two different angles. The point of a chamfer is to remove the sharp (?) right angle on the ID of the case mouth for 2 reasons.

--So there is no shaving of the brass on the bullet exterior.
--Smooth entry of the bullet into the neck during seating.

I'm sure other folks have their reasons which I am interested in hearing.

 

[JFrank]

Just to throw a stick on fire, do ya’ll feel that exact seating force translates to exact seating depth ?

 

[Jager]

Just to throw a stick on fire, do ya’ll feel that exact seating force translates to exact seating depth ?

Probably helps towards a more precise seating depth.

What I found to make a meaningful difference in tightening up seating force is to brush the inside of the case necks; and then to dry-lube the inside of the necks.

 

[rlporter507]

Just to throw a stick on fire, do ya’ll feel that exact seating force translates to exact seating depth ?

I would think not, the press runs down until the load cell feels it stop, were you calibrated the x zero.
maybe?
the 2 angles thing sounds like another experiment. 10 rounds each, 45 degree, vld, and combo, and see how the trace is different. I was surprised with the difference between 45 and vld, complete opposite of what i was expecting.

 

[Ccrider]

What do those high points look like on paper?

 

[Mulligan]

Just to throw a stick on fire, do ya’ll feel that exact seating force translates to exact seating depth ?

Jim,
I have had an one of these presses for several months....... mainly still trying to sort out all that it is telling me.
However to answer your seating depth question, the press has 200 ft-lbs available to seat the bullet using a hand die (Wilson, Micron, etc.,). The operator sets the die up and the press calibrates itself when you instruct it to do so. The only variation I have seen in seating depth with this setup is when you have variation in the seating stem to ogive measurement of your bullets that hasn't been addresssed beforehand.
Hope this helps
CW

 

[JFrank]

@Mulligan
Clay
I have a few things on my bucket list, I wasn’t sure if I wanted to add one of these or not. Looks like a fine seater though.
Thanks buddy

 

[BP1]

Just to throw a stick on fire, do ya’ll feel that exact seating force translates to exact seating depth ?

No

 

[Mulligan]

@Mulligan
Clay
I have a few things on my bucket list, I wasn’t sure if I wanted to add one of these or not. Looks like a fine seater though.
Thanks buddy

I understand, nothing in my little slice of paradise has a permanent home until it proves it's worth.
This one is close, but not there yet.

CW

 

[antunRC]

This is the kind of result I’m looking for.
Once I remove 15-16 foulers, the graph becomes very consistent.
The first graph shows more than 80 rounds.

When it starts looking like this, I know my process is consistent.


It is not requirement to have graphs like this to shoot clean in F-class. Knowing how to read wind and conditions is more important.