.223 case trim variance

[pacpiper]

So I've started the reloading obsession and I'm torn with case trimming since I'm checking size after each one.

The reason being is that I noticed there can be a slight variation after each cut.

It typically ranges from 1.7495" to 1.7505". I've been throwing away cases at 1.7490"

I assume this (variance) is O.K.?

It's literally impossible to get it EXACTLY using a Lyman universal trimmer and depending on how you use your calipers, you can vary anything.

Am I getting too concerned over nothing?

[Steve in PA]

You are wasting cases. I trim my .223 brass to 1.740" for use with the RCBS x-die.

[JB70]

Would the case length or lack of be more important if loading in the max range?

[Steve in PA]

As long as your case length is not beyond the max, you won't have a problem.

If you are crimping your cases, then you want the case to be all the same length. I don't crimp when I reload, so it's not something I worry about, other than trimming them to 1.740".

[Rundownfid]

You don't say what rifle and purpose you have for these reloads. If you are plinking with an auto then as long as they are less than 1.750 you are good to go. However if you want to get maximum accuracy form a really accurate rifle then being more consistent is more important. I shoot 3 gun and go to the trouble of labeling close match and long match, the difference is that one is FMJ bullets in mixed brass, as to brass it is just shorter than 1.750. This is fine for up close and fast shooting, reliable and good for head shots at 50 yds. On the other extrreme I also have a Savage precision rifle, with it it like to use LC brass only, neck sized only and trimmed to 1.745 +/- .005. With individually weighed charges this gives >,50" off a bench or prone of a bi-pod (if I don't F it up). For 3-gun my long match uses LC brass, I just select the ones that happen to be 1.745 +/- .005" from my brass that has been fired in the AR. These I load with a premium bullet, often A-Max, but load on the Dillon w/ as thrown powder charges. I don't get even 1 moa, but close, and that is good for hits out to 3-400 yds, again if I do my part.

So as to your question, it depends....

[shortthrow50]

holy crap. you are being way to anal.9 throw those cases my way

[Yuck]

I have the same question. After full-length resizing most of my cases are between 1.745" and 1.770" in length. Should I worry about trimming the ones past 1.760"?

Basically, how short is too short that it becomes a safety concern regarding increased pressure? How long is too long that the effects on accuracy will be unacceptable for hunting or long-range target shooting purposes?

[Bang]

What would be the mechanics of short increasing pressure?

[Yuck]

Short case, less case volume = increased pressure no?

Or will the bullet just seat out a little higher than with properly sized brass?

[Bang]

Trimming trims the case length by removing metal from the mouth of the neck only. Shorter neck= less friction/tension hold on the bullet, which in theory would lessen pressure needed to overcome the friction on the bullet; or would leave less metal to expand against the chamber wall during the release of the bullet, again lowering pressure. How much? Dunno but it would be less, not more.