New brass 223 case trimming question

[Rgarbarino]

I bought 1000 brand new 223 cases and am getting ready to load them. I've already sized the necks but have a trimming question.

Max length is 1.760 and suggested trim length should be 1.750. If the new cases are shorter than 1.750 is it OK to trim them slightly shorter than that to start with consistent length brass?

Untrimmed they measure around 1.743 - 1.745 so let's say I'd trim them all to 1.743 to start.

I know they will stretch with shooting and will eventually be able to trim them to 1.750 but I'm just wondering if shorter is OK to start and be consistent.

And please don't say read the ABC's of reloading, I have and own other manuals too but you don't always get specific answers to every question that comes up.

Thanks

[drdarrin@sbcglobal.net]

I see nothing wrong with that plan. But 0.002" is an insignificant variance in my book and depending on your trimmer, I doubt you'll be able to improve on it. But if you can, go for it.


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[McGuiver]

I trim all my brass to 1.745". You will be fine. According to SAAMI spec you can trim them anywhere from 1.760" to 1.730".





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[Rgarbarino]

Thank you, exactly the answers I'm looking for.

[OpenSightsOnly]

No need to fudge with brand new brass. BTW, if you trim it shorter than 1.750" you may run into a case with not enough neck tension. I trim the brass at 1.750" and never had the need to crimp.

Also, your 223 load and chamber temp will also affect the brass stretch.

I always works with a batch of 88 pieces of brass, and set to trim at 1.750". After firing the batch about 35 to 40 will be somewhere between 1.753" to 1.754" while the rest are at 1.759" to 1.760".