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Is constant case trimming necessary? This is what I found.

With a power trimmer (I have a Gracey with a Giraud cutter) it's faster to trim than it is to gauge, and I get the inside and outside chamfer at the same time. I use a custom .223 chamber with a length to the start of the freebore of 1.765" and trim to 1.760" after each firing. I anneal and full-length resize my brass after each firing for best consistency.
 
If you use Precision Bushing Bump Dies, your brass won't grow.
And, chamber reamers are made to cut about .020 longer that "listed Max Trim length".
Use the Sinclare chamber measurement plug gages, measure YOUR chamber and see for yourself.
 
If you are going to trim to maximum length, or longer, you need to be more concerned about base to shoulder than you might normally be.

It’s the distance between the point of contact of the shoulder and the transition from the end of the neck in the chamber that will ruin your day. Overall Length of the case is more or less meaningless for this measurement other than to serve as a warning.

The neck of a case with so called maximum headspace, minimum from base to shoulder, will have maximum neck length. The opposite is also true. Maximum base to shoulder, minimum neck length. This is normally a difference of about .010” in neck length.
The problem is that the overall length is exactly the same.

So basically your rifle’s chamber, bolt face to shoulder measurement, determines how long your neck can be. A short body, with a long neck, can have you headspacing off the rim of the neck.

If you size your case to minimum headspace, and maximum + neck length, the danger is case stretch, if the case can’t stretch at the body, it has to stretch at the neck, possibly more than normal. Watch out for bullet pinch where the neck stretches into the taper In the chamber where it transitions from outside neck to bullet diameter.

Normally before you get a pressure sign due to the case pinching the bullet, you might notice a decrease in accuracy. If you pay attention to your brass tho, you will notice that the rim of the neck rolls over. If you miss that, then the next sign might just be a popped primer.

SAAMI built in safeguards for mass production, removing those safeguards just requires a bit more attention. Kind of like removing all the covers off a grinder so you can actually get something done. Just pay attention.
 
Clancy I trim all my 223 loads cause the brass is range picked up and I have no idea what its length is, and all of the cases that I strive to get good as possible accuracy from. hunting and plinking not so much. But I am super curious as to what you trim with that makes it "enjoyable" I have never found that to be the case, but I would like too.
 
@ebb a world’s finest trimmer, either in a drill press/grinder motor or lately I’ve just been clamping my dewalt in a padded vise, angled mouth down so the chips don’t fall into the shoulder area. It’s so fast it’s not fair.

They go from there to a bin to have the outside cleaned up and then another to have the inside done. I do those two operations by hand, no power.
 
I've used a bunch of different ways and never really found a way I am totally satisfied with. Currently i use a Lyman Brass Smith trimmer and like it except for the fact it doesn't chamfer the neck.
 
I have a Hornaday Duo that is set up with a vld inside chamfering tool and an outside chamfering tool. I use this after the Lyman Brass Smith.. it gets the job done fast enough for me.
 
I'm a big fan of using a gauge to see just how long my chamber is, and then trimming cases .010" under that length. I keep that dimension for the particular rifle in my die box.

The down side of that is that I won't share my ammo with anyone else with an unknown chamber length. -- wait a minute, maybe that's an up-side. ;) jd
 
After having 7mm Rem Mag not chamber after the 2nd reload, i "check" trim every time I load.
Lee case length gauge and a cordless drill.

Though most of my rifles are used for hunting and informal target shooting.
 
D Coots said:
They do?

I'd like to see someone prove that a couple thou of length shows up on paper.

My Grandfather came to Iowa from Missouri in a boxcar with his mules and farming equipment. Show me.

Later
Dave
Click to expand...
Dave, I don’t do 90% of the stuff that everybody on here says is nessessary.
I try to make the best bullets I can. I try to keep a competitive barrel on my rifles. And I try to keep the darn things in tune.

I do have these little things I made up. I can stick my cases in every so often to see just where they are.
the one on the left is 6PPC, the middle 6BRA, and the one on the right is 30BR.
IMG_0761.jpeg
 
Last edited:
:cool: Yikes Al..........:rolleyes:

Everyone can obsess over anything they want.

Different disciplines, Different obsessions. Some necessary, some not.

Do your own thing....

When I read about someone with a factory 223 shooting bergers, trimming every time, and annealing before sizing every time, I say to myself....SELF...they can do things however they want.

You do things your way, I'll do them mine.

Damn

Later
Dave
 
Last edited:
D Coots said:
:cool: Yikes Al..........:rolleyes:

Everyone can obsess over anything they want.

Different disciplines, Different obsessions. Some necessary, some not.

Do your own thing....

When I read about someone with a factory 223 shooting bergers, trimming every time, and annealing before sizing every time, I say to myself....SELF...they can do things however they want.

You do things your way, I'll do them mine.

Damn

Later
Dave
Click to expand...
I hear 'ya, Dave. :) Lots of people would be surprised if they checked how long their chambers actually are. I use these case length plugs for every chamber (some Sinclair, some home made). Stan made a chamber cut away gizmo for every new reamer he used for barrels...nice to have a visual, too.

Good shootin' :) -Al
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