TrimMate Idea PUT TO Rest

[scrat]

for overall length when used properly with the lee zip trim. i have not had any problem. I would love to get one of those Giraud. However with the price. i dont think i could ever trim enough cases to make it pay for itself. so knowing when used properly the lee zip trim will do its job with the flash hole pin being stopped to avoid excess case trimming. i am confident and happy with what i have. my cases are all uniformed correctly at the same length.

[rksimple]

for overall length when used properly with the lee zip trim. i have not had any problem. I would love to get one of those Giraud. However with the price. i dont think i could ever trim enough cases to make it pay for itself. so knowing when used properly the lee zip trim will do its job with the flash hole pin being stopped to avoid excess case trimming. i am confident and happy with what i have. my cases are all uniformed correctly at the same length.

I agree completely. If it works for you, and its consistent, do it. Before I got my Gracey, I trimmed with the Lee and a Hornady trimmer. I was still able to shoot MOA to 600 yards. It worked, plain and simple. I'm sure you can make loads that would do same.

Supersonic found something that works for him, and I'm not going to tell him its wrong if it works. If he were getting inconsistent results, that would be a different story.

[supersonic]

R.k>: thanks for the kind words. But in reality, I did not completely think my idea through, so in all truthfulness, the idea turned out to be a failure. Oh, and thanks to most of the other posters who decided to rip me a new one for trying to invent something that would save people time & money, I will keep these kinds of things to myself in the very near future. Thanks, guys. I owe you one.

[xrMike]

I use the Lee case tools also, but I tighten the lockstud into a battery-powered drill.

I bought the pin/cutter tool with the big oak ball on the end. I hold the cutter tool in my left hand and the drill+lockstud+brass in my right and operate the drill at low speed until no more metal comes off, then I drop the cutter tool and pick up the chamfer tool.

After I developed a routine, I measured 20 cases and all of them were within .001" with a couple out to .002".

I don't see how you can be getting an accurate/consistent length without the pin bottoming against the lockstud, but if you are, that's all that matters I guess.

Edited to add: Hey Supersonic, don't be discouraged! Keep sharing buddy. The court of public opinion can be harsh sometimes, but it's a valuable tool for improving your ideas and processes. :thumbs up:

[PistolPete75]

good idea, you don't want people to steal your idea!

[rksimple]

R.k>: thanks for the kind words. But in reality, I did not completely think my idea through, so in all truthfulness, the idea turned out to be a failure. Oh, and thanks to most of the other posters who decided to rip me a new one for trying to invent something that would save people time & money, I will keep these kinds of things to myself in the very near future. Thanks, guys. I owe you one.

I'll look at my Lee trimmer when I get home. I have done it the way you describe with no issues. Maybe I was the one who got lucky.

[PistolPete75]

i like your invention. when you get the bugs worked out, i'll be your first customer.

[ar15barrels]

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

<snipped>

First, I reload 223 by the thousands.
I don't have time to deburr flash holes, nor would it matter as I am mostly shooting steel plates and cardboard in action type matches.

Now on to the importance of trim length datums...

I disagree with Doug Girard.
Hear me out.

The primary reasons for trimming are two-fold.
First, you don't want the case to be so long that it could jam into the end of the chamber's neck and elevate pressures.
This has a relatively low tolerance requirement.
The case just needs to be short enough to NOT hit the end of the chamber's neck.

Second, you want the trim length consistent in order to apply a consistent crimp.
This has a much higher tolerance requirement as a consistent crimp is important to consistent ignition and resultant accuracy.

So, let's assume that cases will be sized, but due to differences in brass hardness or annealing, that the headspace lengths will all be within 0.003" or so throughout a run of cases.
This is about what I have found when measuring a bunch of cases of all different headstamps run through the same sizing setup.

If you trim these cases referenced from the shoulder and make an assumption that the case trimmer will trim to 0.001" repeatedly, you SHOULD find that the OAL is all within 0.002" to 0.004" when measured to the case head.

Now, look at a reloading press and you will note that the datum point is the case head.
When you are shoving the case into the sizing die, the case head is pushed against.
When you are shoving the case into the seating die, the case head is pushed against.
When you are shoving the case into the crimping die, the case head is pushed against.
The distance from the feature of the die that causes the crimp is only held consistent to the press ram (shellholder/case head), NOT to the case's shoulder.
So, in order for crimps to be consistent, you need the OVERALL LENGTH to be consistent, NOT the length from the shoulder.

Now look at a trimming solution like the lee mentioned above, or the Dillon that I use.
The trim lengths will generally be between 0.001" to 0.002" throughout the whole run of brass.
The shoulder's length is NOT a factor.
With the more consistent trim length, you will get more consistent crimps.

Of course, if you are not crimping, it will NOT matter what datum is used to determine trim length.
You are only working in the low tolerance requirements of just being sure that your cases are not too long.

[rksimple]

First, I reload 223 by the thousands.
I don't have time to deburr flash holes, nor would it matter as I am mostly shooting steel plates and cardboard in action type matches.

Now on to the importance of trim length datums...

I disagree with Doug Girard.
Hear me out.

The primary reasons for trimming are two-fold.
First, you don't want the case to be so long that it could jam into the end of the chamber's neck and elevate pressures.
This has a relatively low tolerance requirement.
The case just needs to be short enough to NOT hit the end of the chamber's neck.

Second, you want the trim length consistent in order to apply a consistent crimp.
This has a much higher tolerance requirement as a consistent crimp is important to consistent ignition and resultant accuracy.

So, let's assume that cases will be sized, but due to differences in brass hardness or annealing, that the headspace lengths will all be within 0.003" or so throughout a run of cases.
This is about what I have found when measuring a bunch of cases of all different headstamps run through the same sizing setup.

If you trim these cases referenced from the shoulder and make an assumption that the case trimmer will trim to 0.001" repeatedly, you SHOULD find that the OAL is all within 0.002" to 0.004" when measured to the case head.

Now, look at a reloading press and you will note that the datum point is the case head.
When you are shoving the case into the sizing die, the case head is pushed against.
When you are shoving the case into the seating die, the case head is pushed against.
When you are shoving the case into the crimping die, the case head is pushed against.
The distance from the feature of the die that causes the crimp is only held consistent to the press ram (shellholder/case head), NOT to the case's shoulder.
So, in order for crimps to be consistent, you need the OVERALL LENGTH to be consistent, NOT the length from the shoulder.

Now look at a trimming solution like the lee mentioned above, or the Dillon that I use.
The trim lengths will generally be between 0.001" to 0.002" throughout the whole run of brass.
The shoulder's length is NOT a factor.
With the more consistent trim length, you will get more consistent crimps.

Of course, if you are not crimping, it will NOT matter what datum is used to determine trim length.
You are only working in the low tolerance requirements of just being sure that your cases are not too long.

I like your assessment, and at this point we're splitting hairs. Neck tension is another critical factor that can be determined by neck length. Following Doug's logic, this can be affected by conventional trimming methods.

Again, this is something so minute that practicing another 20 rounds a week would yield much better results than worrying about it.

[ar15barrels]

I like your assessment, and at this point we're splitting hairs. Neck tension is another critical factor that can be determined by neck length. Following Doug's logic, this can be affected by conventional trimming methods.

Again, this is something so minute that practicing another 20 rounds a week would yield much better results than worrying about it.

I like splitting hairs.
It's easier than splitting atoms.

I'll hazard a guess that the consistency of crimp caused by difference of a few thousandths OAL difference will have MORE effect on the accuracy than the difference in neck tension from a few thousandths neck length difference.

Remember that the bullet seating datum is the case head and the bullet's ogive.
If you are seating bullets deep enough that the bearing surface protrudes into the shoulder, then the NECK length variance will effect the neck tension.
If you are seating bullets shallow enough that the bearing surface does not seat below the case neck, then the OAL length variance will effect the neck tension.
In the first case, ultimate accuracy is obtained by controlling for NECK LENGTH and not OAL.
In the second case, ultimate accuracy is obtained by controlling for OAL and not NECK LENGTH.

[rksimple]

I like splitting hairs.
It's easier than splitting atoms.

I'll hazard a guess that the consistency of crimp caused by difference of a few thousandths OAL difference will have MORE effect on the accuracy than the difference in neck tension from a few thousandths neck length difference.

Remember that the bullet seating datum is the case head and the bullet's ogive.
If you are seating bullets deep enough that the bearing surface protrudes into the shoulder, then the NECK length variance will effect the neck tension.
If you are seating bullets shallow enough that the bearing surface does not seat below the case neck, then the OAL length variance will effect the neck tension.
In the first case, ultimate accuracy is obtained by controlling for NECK LENGTH and not OAL.
In the second case, ultimate accuracy is obtained by controlling for OAL and not NECK LENGTH.

I agree. I don't crimp my match ammo, though. And with as long as match bullets are, seating below the neck/shoulder junction is often a necessity.

Doesn't the Lee factory crimp die crimp evenly, regardless of OAL? Or is it at least advertised as doing so?

[ar15barrels]

Doesn't the Lee factory crimp die crimp evenly, regardless of OAL? Or is it at least advertised as doing so?

It's advertised as doing that.

It's basically just a 6 jaw collet that smashes the case neck against the body.
What I found is that it also distorts the bullet jacket.

I prefer a taper crimp with a consistent trim length if I need to crimp.
I crimp for autoloaders and slow powders that benefit from extra bullet-pull.

[supersonic]

i like your invention. when you get the bugs worked out, i'll be your first customer.

I'll put you on my list & PM you when it's been perfected. You will save MANY $100's over the Dillon's/Giraud's/Gracey's. I will PM you w/ more details right now.

[phish]

I'll put you on my list & PM you when it's been perfected. You will save MANY $100's over the Dillon's/Giraud's/Gracey's. I will PM you w/ more details right now.

or, re-read Technical Ted's post

[supersonic]

or, re-read Technical Ted's post

THEN read the one right below it and be done with it!!!