How often to trim 223?

No offense intended, don't know how much experience you have, but are you trimming before or after resizing? Should be after.

ohihunter2014 said:

If I'm looking to squeeze every last MM of accuracy out of my 223 reloads how often would you trim LC brass? I've been running them through the cutter after every reload and some I notice it doesn't take anything off and some I get shavings. I don't get that either how some cut and some don't.

I'm trimming 1.750 I think it is-whatever the shortest I can go is. would it be okay to let them get close to max or just keep doing what im doing?

What's your thoughts?

Click to expand...

I trim when they need it. Not to sound like a wise guy, but part of my case prep is after resize I check every case by using the Lee pilot and trimmer. If they don't get anything trimmed they pass, if they are too long they get trimmed. I check every case every resize though. I know that seems like a lot of handling but its how I do it. For 30-06 or .243 its not bad because I don't load near the volume as I do .223. For .223 I usually process brass in bulk so when I'm doing it I'm doing quite an amount.

I'll add that case stretch will be dependent on how far you are pushing the shoulder back, if you are using a bolt vs autoloader, etc.

-Jeff

It goes without saying, but I'll reiterate it anyway - resize before trimming.

Here's what I do - For my initial loading, I resize, then measure all of my brass and pick the appropriate minimum length for the lot, then trim the entire batch to that length. Then, for subsequent loadings, I pick my desired case length (may not necessarily be the same length as my first trimming), lock a set of calipers to that length, set two buckets in front of me at the press, then as I resize, I try to pass them through the caliper. If they go through, they go into the pass bucket, if they're too long, they go into the trim bucket. Trim & treat those which grew and put them back in circulation.

For .223rem, you are doing something very wrong if you're experiencing case growth with every firing. I'm not one to tell a guy with 223rem you should only need to trim one time ever, but it should be a very rare thing - depending upon load, I expect no trimming needed for ~90-95% of my cases after each firing, ideally less.

Neck thickness run out and extent of work hardening will make a lot more difference in your neck tension, and resulting accuracy, than a few thousandths of neck length. If you're not neck turning and running a regular interval controlled annealing program (not a water pan or hand drill method), then length sorting all of your brass to the nearest thousandths won't really matter in the least.

Varminterror said:

For .223rem, you are doing something very wrong if you're experiencing case growth with every firing. I'm not one to tell a guy with 223rem you should only need to trim one time ever, but it should be a very rare thing - depending upon load, I expect no trimming needed for ~90-95% of my cases after each firing, ideally less.

Click to expand...

Agreed. After the initial trim you shouldn't see much if any growth for a few firings.

-jeff

I trim LC brass once. I trim it to 1.748. After that I use the RCBS small base X die. The brass will lengthen a couple thous and that's it.

FC brass I don't trim since it's all around 1.742/4.

SAAMI spec for .223 brass is 1.740 to 1.760. Most loading manuals shoot for the middle at 1.750.

I don't trim for accuracy, I trim for safety. Meaning, as Varminterror said, I think a few thousandths have negligible effect on practical bullet pull/accuracy. But, over length to the point of crimping the bullet into the end of the chamber neck is harmful if not dangerous to pressure/accuracy. I have Sinclair neck length gages and I record max. case length for each rifle. In .223/5.56, I've never gaged a chamber shorter than 1.772. So, I trim when they get between 1.760 and 1.765. The rifles I shoot most are mostly custom heavy prairie dog rifles capable of 1/2" - 3/4" groups. I don't think they (or I) would do any better with brass all trimmed to the same length. If I had a Girard or WFT I might trim every firing. I do use a motorized RCBS with a 3-way cutter, but if I can avoid trimming 3000+ cases for several cycles, I do.

My brass prep for 223 is this:
1. Deprime using universal
2. Wet clean using SS pins
3. Anneal all
4. Size
5. Trim set 1.755" (Press mounted Trim-It II)
6. Sort by year then storage till ready to load.

It's faster to run them through the trimmer than it is to measure them.
I have never had one split out yet. Have some brass I retired due to loose primer pockets, 10+ reloads.

Cannibul said:

...snip...
SAAMI spec for .223 brass is 1.740 to 1.760. Most loading manuals shoot for the middle at 1.750.

Click to expand...

The SAAMI min is 1.730" per the drawing.

I attempted to answer a very similar question (specific to AR15s in my case).
https://www.mdshooters.com/showthread.php?t=189714

Answer is simple, trim them as needed to same length each time anywhere between minimum and maximum. I drop mine into a gauge to check the length.

your process (from post # 10) is correct for trimming. case length does not affect accuracy one way or another, imo. keep doing what you are doing.

luck,

murf

If you are going for accuracy ( all cases should be the same length ) -- trim every time
223 Rem. SAAMI case spec. is -- 1.760 max. to 1.740 min.
almost all manuals recommend trim to -- 1.750

Along with all the good advice in previous posts I have found that the necks split much sooner if the brass is not trimmed to spec. and that varies with the depth of your rifles chamber. Too long causes other problems also.

I trim 223 brass on the first load, regardless of whether its new or once-fired. After that, I generally trim about every three reloads. Even then, most of the cases are still in spec and the trimmer doesn't cut anything.

I lose them before i need to trim them.
Im not horribly concerned with length unless it gets to max. Im also not trying to load match grade ammo, 1.5-2 is the best my mini will put out..........And the sheer volume of cases i have kinda killed my interest in doing them all.
Other cartridges Ill trim them on first loading, then check at every loading there after.

I run them through the trimmer after every sizing. Most do not need trimming.

I set my Lee trimmer into my drill press, find a couple cases over 1.750", set it up to trim to 1.750", run 'em all through, if they are too long, they trim, if not, they don't.

ohihunter2014 said:

I remember seeing something awhile back about trimming or not trimming too much made the necks split and then you had to anneal.

Click to expand...

Trimming doesn't cause necks to split, nor does trimming cause necks to work harden. Work hardening is exacerbated by over sizing, but is only a function of "working" the brass - sizing down to neck the case in the sizing die, sizing up by pulling the expander through the neck, pulling neck tension by seating bullets, and - most significantly - firing the case. Trimming can prevent splitting, as it turns off the thinnest tip of the lip, which has experienced the most working - double whammy to initiate a split.

Annealing "detempers" the brass, in a matter of speaking, to reduce/eliminate work hardening effects in the case neck and shoulder. I wouldn't say annealing is dependent upon whether you're trimming or not, other than if you don't trim, but DO anneal, you might stop that feathering lip from splitting a load or two extra, but really, if you're firing rounds, the shoulder and neck are work hardening, and eventually they're going to split if you don't anneal. Even if you keep a piece of brass properly annealed and trimmed, eventually it's going to loosen its primer pocket, and if you manage to keep your primer pockets happy, EVENTUALLY it'll torch through the case wall because of the blast erosion... Brass is consumable. We do what we can to extend its life, but it won't last for infinite firings. Whether cases split before pockets loosen depends on a lot of factors, but using moderate loads, trimming to consistent length, and annealing when appropriate helps make brass last a long, long time.