How many times you can fire before trimming?

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majormarine

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How many times you can fire before trimming?

for 223 rem, the lee reloading book says the max case length is 1.76".

i measured my 1-fired cases and they are all around 1.769".

i don't know if the 0.009" is significant or not, but if i can skip a few times before i have to trim, it will be nice!
 
trimming

as long as all of your cases are the about the same length and you do not go over the maximum case length you are okay. The only time it is really critical is if you are crimping, by having all your cases the same length you will achieve the same level of accuracy. longer and shorter cases when mixed may not shoot into the same poi.
 
Try a sized, untrimmed case in the firearm you are using them in. If they are already over max. length, chances are if they don't cause a stuck bolt or hard extraction now, they will once you fire them off again.
 
"...about the same length..." Nope. 'About' doesn't count for good accuracy. Different lengths lead to bullet seating and OAL issues.
"...they are all around 1.769"..." They're 9 thou over max and 19 thou over the 'trim-to' length. Trim 'em to 1.750"(the 'trim-to length), but you only need to check the lengths every time(a calipre will do, but get a case length guage. It's faster.). You won't likely have to trim every time. It's highly unlikely they'll stretch 10 thou with every firing.
Remember to chamfer the inside of the case mouth and deburr the outside after trimming.
 
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How often you will have to trim in the future depends on how oversize the chamber is and whether you full length or neck size. The more the brass is expanded and then squeezed back down to standard dimension, the more brass with extrude forward.

In many of my rifles, neck sizing only, I rarely if ever have to trim.

On some of my milsurp rifles they are way over length after resizing due to the over sized chambers.
 
ooops

I missed it, i thought the max case length is 1.76" was trim to length. Your going to have to trim them back to the trim to length prior to reloading again.
 
Purchase one of these, then make up your mind about when to trim after you have measured the neck length in your chamber.
G-224.jpg

http://www.sinclairintl.com/cgi-bin/category.cgi?category=RESDTCL&item=G-224&type=store
 
majormarine said:
How many times you can fire before trimming?

for 223 rem, the lee reloading book says the max case length is 1.76".

i measured my 1-fired cases and they are all around 1.769".

i don't know if the 0.009" is significant or not, but if i can skip a few times before i have to trim, it will be nice!
Click to expand...

Well, I'd recommend trimming a bottlenecked case after every firing. I find that my 223 brass "flows" like the devil. I've trimmed as much as 9 thou after one firing. Now that was a fairly warm load in my Remington 700, but bottlenecked cases do flow. Now straight walled pistol brass doesn't seem to flow for me at all, even after several firings. I don't own a straight walled rifle so I can't comment there.
 
Full length resize your case before you measure. If fact measure it, FL resize it and measure it again. You will see that FL resizing stretches the case more than you think.;)
 
I trim after every firing for two reasons. First, it is one little thing I can do that contributes to the consistency and hopefully accuracy of my loads. I also use the hand powered Lee system and I find if I wait too many firings I have too much to take off - easier and quicker to take a little off each time rather than a lot at one go.
 
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