Gidday guys, I’m reloading ..223 for my Baikal - it’s shooting bloody well with 25.5gn of ADI 2206H (v similar to BM2) in various cases mainly Federal, CCI primers and 55gn Blitzkings averaging 1 inch groups at 200 yards with a muzzle velocity of 3280 FPS which admittedly is fair cranking. No pressure issues noted.
I’m about to reload a bunch and want to know how crucial empty case length is. I was given information when I started that case length between 1.756 - 1.760 was optimum but I’ve just measured 200+ cases and the majority are 1.745 - 1.750
How crucial is case length.
PS I’ve searched the site but can’t find answers to my question.

I haven't measured my brass just load it.

Read this.

You just hit on something that probably 99% of shooters might never realize.
There are specs on case trim length, and then there are specific dimensions of a particular rifle.
The published specs are simply GUIDELINES that are supposed to be safe in ANY rifle made to the guidelines.
Now, MOST factory chambers will safely take cartridge cases considerably longer than the published specs.
I call these chambers "lawyer approved" as they are made longer to help keep pressures lower.
The unfortunate side-effect is reduced accuracy potential.

Sinclair sells a simple tool to measure YOUR chamber length.
Once you determine what your rifle can take, trim 0.010" to 0.015" shorter and be done with it.
If you have a chamber that's 0.060" longer than spec, I doubt you would ever need to trim your cases before they wear out.

That is post number 8 here. www.calguns.net/calgun...hp?t=95166

Also this.

www.handloadersbench.c...ass-length

Case length is not critical so long as it is shorter than the chamber of the gun it is shot in. The maximum SAAMI brass length is typically 0.010" shorter than the minimum SAAMI min chamber length so you case length can actually be longer than max case length and you can be ok. I forgot to check my case length on a bunch of 6.8mm brass and was 0.015" past max case length and the gun was running fine so it chamber must have been longer than SAAMI minimums.

Case length becomes critical if you use the integral crimp feature in the bullet seating die. Then case length has to be precisely the same all the times or you run into issues. So avoid all that and make sure your bullet seating die is backed out enough that your case mouth never touches that features - then you will never have problems. Only use a collet crimp die if you crimp. Elvis taught me that.

It depends. I simply use a Lee case trimmer and cutter tool. When it stops cutting the case is at minimum length. Then I chamfer and deburr the case mouth. Since using the Lee tool I have never had a problem and never looked back. All the best...
Gil

Gil Martin wrote:

It depends. I simply use a Lee case trimmer and cutter tool. When it stops cutting the case is at minimum length. Then I chamfer and deburr the case mouth. Since using the Lee tool I have never had a problem and never looked back. All the best... Gil

I have those, amazing how well they work isnt it? Lee equiptment always has such simple yet useful designs.


-DallanC

me three on the LEE .....use of a cordless drill just makes life so simple,resize it,chuck in chuck thingymebobby,quick whirl to trim to length,grab lee champher tool,quick inside then outside deburr,if feeling really good grab polt pad and give another whirl getting mouth really smooth and cleaning case at same time...too mecky bro,too mecky

Thanks all, I’ll use cases in 0.05 length batches and see how we go. Bugger, back to remeasuring the big bag approx 300 cases

radar!?! So long as you are below max, it doesn't matter. I sure wouldn't spend the time measuring them even if I was trying to hit a fly at 200m. They are close enough., IMO.

Do keep an eye on case length when using the lee trimmer, as the tip does wear down.
I trimmed a couple of thousand .308 cases & the tip wore down 0.010"

radar wrote:

Thanks all, I’ll use cases in 0.05 length batches and see how we go. Bugger, back to remeasuring the big bag approx 300 cases

Get a Lyman case length gauge, makes life easier.

www.midwayusa.com/prod...h-gauge-ii

Then you only have to trim the ones that are too long.

Measure and trim cases after sizing.
Your brass is likely to be shorter after firing but before sizing.
The sized brass should be at least .002" shorter than the chamber in your rifle.
You want to avoid pinching the mouth between the bullet and chamber throat. That raises pressures dramatically, even more than seating the bullet in the lands.