TrimMate Idea PUT TO Rest

[supersonic]

No longer for public viewing as work progresses.

[PistolPete75]

beautiful! freaken genius. can you do the converision for me if i send you my trim mate? i'll be your first customer. need one in .223 and .308

[rksimple]

Good work. I've chucked them in a drill press before, but not in a trim mate.

[scrat]

uh am i missing something. the lee trimming tool is designed to use with the lock stud. the lock stud blocks the primer hole. so that you do not over trim the case. the way you have it set up with out blocking the end of the bullet you will trim too much

[rksimple]

uh am i missing something. the lee trimming tool is designed to use with the lock stud. the lock stud blocks the primer hole. so that you do not over trim the case. the way you have it set up with out blocking the end of the bullet you will trim too much

4th pic down shows it pretty well. Looks good.

[scrat]

ya shows it really good. shows the pin going through the primer pocket. meaning you can just cut away at the brass non stop. Bad idea the tip of the pin is supposed to press against the stud keeping the measurement on the case correctly.

am i missing something otherwise bad idea. unless the rod is redsigned and extended to compensate for the missing piece behind the primer pocket

[rksimple]

ya shows it really good. shows the pin going through the primer pocket. meaning you can just cut away at the brass non stop. Bad idea the tip of the pin is supposed to press against the stud keeping the measurement on the case correctly.

am i missing something otherwise bad idea. unless the rod is redsigned and extended to compensate for the missing piece behind the primer pocket

I don't know what kind you have, but the Lee I have stops with the spindle hitting the inside of the case...just like the pictures above. Thats how its calibrated. The pin goes through the flash hole every time.

[ar15barrels]

I don't know what kind you have, but the Lee I have stops with the spindle hitting the inside of the case...just like the pictures above. Thats how its calibrated. The pin goes through the flash hole every time.

That's not right.
Your datum point becomes the inside of the case so you rely on the trim-length to be set by stopping inside the case.
The thickness of the case head is going to vary, especially if you take into account the burr inside the cases from when the flash hole was punched...

The normal lee setup required the shellholder to be tightened against the case SPECIFICALLY so that the pin will stop against that flat face where the head of the case is seated against.

Think very carefully about what you are saying about referencing from the inside of the case.
Go trim a dozen cases in this manner and report back on the consistency of the trim lengths.

[grammaton76]

I know the Giraud uses the shoulder of the case. I still haven't used the thing yet, but I did play around with the adjustments a little.

[supersonic]

That's not right.
Your datum point becomes the inside of the case so you rely on the trim-length to be set by stopping inside the case.
The thickness of the case head is going to vary, especially if you take into account the burr inside the cases from when the flash hole was punched...

The normal lee setup required the shellholder to be tightened against the case SPECIFICALLY so that the pin will stop against that flat face where the head of the case is seated against.

Think very carefully about what you are saying about referencing from the inside of the case.
Go trim a dozen cases in this manner and report back on the consistency of the trim lengths.

Randall,
As a rule, I get rid of flash hole burrs before loading any case (except Norma, Lapua, some others). I've been using the lee system for 2 yrs. and have YET to measure a case that is not perfect. They don't guarantee their products for nothing. BTW, after I read what you said, I tried it without deburring a new winchester case......still PERFECT. Is it just me?

[supersonic]

Good work. I've chucked them in a drill press before, but not in a trim mate.

Have YOU had consistent results w/ the LEE trim system as I have?? I mean, they are fool-proof!!!!

[scrat]

when used properly with the shell holder in place to prevent over trimming. otherwise when used inproperly then the answer is no.

go ahead send this to lee so they can laugh and ask you how you put the lock stud on each case.

let me say it again. unless you redesign the rod. its a poor design. if it works on your case. this does not guarantee it will work on others. if i take a 30-30 case and do not put the lock stud on the case and start trimming the case will probably 30 thousands shorter than all the others. due to not having something stop the pin from going through the flash hole out the back. The tool is designed to be used with the lock stud so that when you place the rod in the case the pin goes in the flash hole and stops agains the lock stud. making the cases uniformed. otherwise if it comes out the flash hole your trimming too much.

[scrat]

Sorry but this still beats yours



but then nothing beats the garrand

[rksimple]

That's not right.
Your datum point becomes the inside of the case so you rely on the trim-length to be set by stopping inside the case.
The thickness of the case head is going to vary, especially if you take into account the burr inside the cases from when the flash hole was punched...

The normal lee setup required the shellholder to be tightened against the case SPECIFICALLY so that the pin will stop against that flat face where the head of the case is seated against.

Think very carefully about what you are saying about referencing from the inside of the case.
Go trim a dozen cases in this manner and report back on the consistency of the trim lengths.

Out of a couple hundred cases, +/- .002". I'm fully aware of the "referencing from the inside of the case" issue. Same issue applies when referencing the outside of the case head (to a lesser degree). But then again, you need to consider very carefully what's going on when trimming if you're not using anything but a Giraud or a Gracey. Those are the only two that trim using the shoulder as a reference point. The shoulder and the case mouth are the only points that really matter in OAL.. Think about it.

I haven't used my Lee, or any other trimmer for that matter, since I got a Gracey.

Its all moot anyway if you're not using a giraud or a gracey. Doug explains it best:

When a trimmer grips the case rim, like the RCBS unit, it will control the distance from the rim to the case mouth to an exact length. The downside is that there is no guarantee that the brass has been resized, or resized properly to any specific given dimension. That type of trimmer, as well as the Lee, Forester, or any lathe type is that they don't care about what is between the rim and case mouth. Your brass could be undersized, oversized, some combination of both, and/or not resized at all.

With the Giraud and the Gracey, the case holders are indexing the cases off the shoulder of the case. These trimmers will trim the brass from the shoulder forward to a given dimension, but not necessarily the exact same dimension from case to case if the headspace dimensions vary. The headspace dimension is the distance from the case rim to the midpoint on the case shoulder. This will control how tightly or loosely the case will fit in the rifle chamber. If the headspace is looser than it should be, the case will be sloppy in the chamber, if it is too long, you may have troubles closing the bolt on a loaded round.

Theoretically, if the headspace was way short and the case was sloppy loose, even though the distance from the rim to the case mouth was right on call for SAAMI dimensions, the case could slide forward enough to allow the case mouth to get restricted by the end of the chamber and cause the typical problems associated with cases that are too long.

With the Giraud and Gracey style trimmers, the distance from the shoulder to the mouth is exactly the same from case to case and there is no way the mouth could be restricted by the end of the chamber if the case was trimmed properly. The shoulder of the case would prevent the case from going forward any more and causing problems. Where some people have a problem with these types of trimmers is that the overall length can vary by however much your headspace dimension varies. But that is a function of your ability to consistently resize cases, not the trimmer. The problem is that most everybody measures only the distance from the rim to the case mouth and sees some variation. They don't usually take the time to get a case gauge, like a Stoney Point comparator, and measure the distance from the rim to the shoulder and see that the variation is there, not from the shoulder forward to the case mouth.

Reloaders who have been making match grade ammo for competition or such usually have learned this the hard way and take more care when resizing brass to make the headspace more uniform. With brass that is consistently resized, the overall length from a Giraud or Gracey trimmer will usually be as uniform as your ability to control that headspace dimension.

Now all the trimmers have the ability to trim a .223 case to 1.750" on a regular basis. But if you don't know that the headspace on the case is .020" short and you only measure the rim to case mouth dimension, you don't know that your case is sliding .020" further into the chamber than you thought and may create problems. With the Giraud and Gracey trimmers, the case holders will typically not work well unless the brass has been resized, so there is one check you can make easily. Does the case go into and out of the case holder easily? If not, check it out. The you can check the headspace of a few cases and see if they are consistent. If they are, you can set the trimmer to remove enough material to know that the case will function properly, and the headspace will prevent the case from sliding around inside the chamber. And lastly, with proper headspace, you stand a better chance of getting accurate loads and longer life from your brass than if the headspace was excessive or random.

Sorry for being so long winded, but I am an engineer. And we all know what that means, I have low earning potential and poor social graces.

HTH,
Doug Giraud

[rksimple]

Have YOU had consistent results w/ the LEE trim system as I have?? I mean, they are fool-proof!!!!

Yep. As far as OAL is concerned, its fine. I don't know if Lee redesigned them to bottom out on the inside of the case or what. The kit to use with a power drill has the lock stud upon which the pin bottoms out. I don't really notice too much of a difference when I used it either way. Maybe I just got lucky. It seems you have as well. If it works well, and is consistent, don't listen to how everyone else tells you its wrong.