223/5.56 Trim Specs

[Henry45]

Hey guys, what are you guys trimming your brass to on your 223/556 brass? I have been trimming mine to 1.750 but got my new Giraud Tri-way and it's set to 1.760.

I know that's max length, but is anyone using that, or are you trimming shorter?

I'm just wondering why it came to max length. Not a big deal, but may be something i just didn't think about when trimming my brass..

Thanks! Have a good shooting weekend!!

 

[Reloadron]

Will it matter? Nope, the trimmed case is still under max length. As to the trimmer:

The overall length of the finished cut can be adjusted by loosening the locking ring on the threaded shaft and rotating the threaded shaft in or out to shorten or lengthen the overall trimmed case length. One complete rotation of the shaft will change the overall trimmed length by approximately 0.072”, one half turn will change the overall trimmed length by approximately 0.036”, one quarter turn will change the overall trimmed length by approximately 0.018”, one eighth turn will change the overall trimmed length by approximately 0.009”.

So adjust the trimmer for 1.750" in the future. My read is it should be easily adjustable.

I always trim all my 223 brass to 1.750 and only after checking the resized case headspace numbers. Once I know the shoulder is where I want it, then I trim. Again the 0.010" shouldn't matter.

<EDIT> That being my 223 brass used in semi-automatic rifles, my bolt gun 223 only gets neck sized till it needs the shoulder bumped back.</EDIT>

I also noticed this:

Operation
This tool indexes cartridge cases off the bottleneck shoulder and will trim each case inserted into it to a repeatable length from the shoulder forward to the case mouth. If you experience variations in overall case length using this tool, it is because the headspace dimension of the resized cases is not consistent from case to case. Differences in cartridge case brand, number of loadings, type and amount of case lubricant used during resizing, type of reloading dies used, and method used to resize the case will have a great effect on the consistency of the finished product. The more consistent the resizing process is, the more consistent the finished trim length will be. No trimmer indexing off the shoulder will correct poor resizing technique.

You really want to pay attention to that information if you expect uniform case OAL following trim.
Ron

 

[rg1]

I trim to the max length at 1.760" which means I usually trim again after shooting them again. If I had your trimmer I'd leave it set to 1.760" and trim every time but if you do trim to the recommended trim length at 1.750 you can load and shoot it a couple times before trimming again. At 1.760" the case mouth on my 55 FMJ's is just where I want it for crimping while 1.750" is a little short.

 

[matrem]

You mentioning 5.56 makes me assume you're not referring to bolt guns?
For semi autos, I always trim fairly close to minimum, and occasionally (accidently) a bit shorter. Guess I dislike trimming so much, that when I do it, I do it.
For Bolt guns, I necksize most of the time, and when I do trim, it's still usually between 1.750 & 1.755.

 

[Walkalong]

I always trim to 1.750.

 

[spitballer]

1.75"

 

[Sunray]

Trim-to is 1.750". As long as the cases are at or under 1.760", you're fine. You'll likely have to trim after the first firing though.
You'd have to ask Giraud why they ship that way.

 

[edfardos]

1.742, wont have to trim twice. Plus its the length my lee pin happens to have worn down to.

 

[amlevin]

What really matters is how long the chamber is in the firearm. As long as there is sufficient clearance between the chambered case and the front of the chamber (neck portion) then actual trim length is moot. .010"-.015" is all you need but if you haven't measured the chamber length how will you know what you have?

 

[loose noose]

My cases are all trimmed to 1.750 after each shooting, I consider it a necessity in order to get the most accuracy and reliability out of my ammo. Note I also sort my casing into the brands etc.

 

[joustin]

I always trim to 1.75, its easier and avoids issues

 

[tcoz]

I set my caliper to 1.758. If the case slips through, I don't trim. If it doesn't, I trim to 1.750

 

[carbine85]

The difference is splitting hairs. It won't make any difference in performance.

 

[243winxb]

I have been trimming mine to 1.750" The RCBS X die gets 1.740" per instructions. There is a "safety zone" built into most rifle chambers that allows for brass longer than the maximum of 1.760"

 

[Reloadron]

I have been trimming mine to 1.750" The RCBS X die gets 1.740" per instructions. There is a "safety zone" built into most rifle chambers that allows for brass longer than the maximum of 1.760"

Ah yes, from our friends at SAAMI.

The Maximum cartridge length for 223 Remington is 1.760" - .030". Now if we look at the minimum chamber specification we see 1.772".

Good point.

Ron