Measuring and Trimming .223 Brass

[kbm6893]

So I’m getting into reloading .223 and have about 1000 pieces of brass sized. I’ve divided the brass into three bins, Need Trimming, Too Short, and No Trim. The manuals all say trim to 1.75 with max length 1.76.

I’m using a Hornady digital calipers there I use to measure completed pistol brass. But if I move the brass a hair either right or left, the measurement changes. So 1.748 can become 1.744.

So I’m going to use the Frankford Arsenal Case Prep Center to prepare my brass. I’d like to set the trim length to 1.748 or so. But the changing numbers are making that difficult. I plan to use a case that is exactly 1.748 to set the trimmer and go from there. So the ones that are too long won’t be a problem, but what of the ones that are measuring less than that? Do I toss them?

I also got the military crimp remover to add to the station.

Am I worrying too much? Is .003 of an inch an issue? I don’t want to have any problems.

Thank for all the advice in advance!

 

[Wise_A]

You're way, way, way overthinking it.

(1) Batch it out into 50/100-round "lots".

(2) When pretty much every cartridge is well over trim-to size, trim, chamfer, and deburr.

(3) When you get X number of case failures--whatever you feel comfortable with--toss the entire lot. Case failure could mean an actual crack or failure, or something like "primer pocket is too loose for my taste".

That's also not how you set a trimmer. Take a case, trim it, and measure it--work from the result. You don't take a case that's the desired length, put it in, and try to tighten up the trimmer.

But yeah, I haven't even bothered trimming some of my brass lots yet, and I'm shooting teensy groups just fine.

 

[kbm6893]

You're way, way, way overthinking it.

(1) Batch it out into 50/100-round "lots".

(2) When pretty much every cartridge is well over trim-to size, trim, chamfer, and deburr.

(3) When you get X number of case failures--whatever you feel comfortable with--toss the entire lot. Case failure could mean an actual crack or failure, or something like "primer pocket is too loose for my taste".

That's also not how you set a trimmer. Take a case, trim it, and measure it--work from the result. You don't take a case that's the desired length, put it in, and try to tighten up the trimmer.

But yeah, I haven't even bothered trimming some of my brass lots yet, and I'm shooting teensy groups just fine.

But what about the pile that is less than 1.748? Obviously don’t trim but should I still load them? Is there a minimum case length? Don’t see anything listed.

And I wasn’t clear on setting the trimmer. I plan to use a case that’s already the length to get me in the ballpark and then trim and measure. A few videos on YouTube I saw say to use that as a starting part. Put the case in so it just barely touches the cutter and go from there.

 

[SMSgt]

But if I move the brass a hair either right or left, the measurement changes. So 1.748 can become 1.744.

No amount of jiggling can make a measurement shorter than what it is, only longer.

If your resizing die is properly adjusted to for correct headspace, any trimming will affect only neck length, and a few thousands of neck length will have no effect on round performance--unless you're obsessed with infinitesimal differences in numbers.

 

[BC38]

But what about the pile that is less than 1.748? Obviously don’t trim but should I still load them? Is there a minimum case length? Don’t see anything listed.

And I wasn’t clear on setting the trimmer. I plan to use a case that’s already the length to get me in the ballpark and then trim and measure. A few videos on YouTube I saw say to use that as a starting part. Put the case in so it just barely touches the cutter and go from there.

The advice I've received here and elsewhere is to use 1.745" as a minimum length. I'm still getting set up for reloading .223/5.56 myself. My plan is to decap and size all my once-fired brass, ream the crimped pockets, and then trim to 1.745". That should ensure that the brass never gets to 1.76" max lengths before it has been reloaded a half a dozen times or so and is ready to be scrapped. Basically the idea is that it should be worn out before it ever needs trimming a second time.

 

[zeke]

Using 223 brass below the trimming depth is not much of a concern. Would certainly not advise waiting till pretty much all your brass is way over the max trim depth. If your brass mouth gets jammed in, your pressures can really increase. A lot depends on your brass and specific firearm, and .003 difference is not that big a deal.

As soon as i detect any brass from a batch over max, the whole lot gets trimmed. Prefer this over checking a bunch of brass.

Than there is the question of where your brass came from, is it all the same kind/batch and what you are going to use it in. Am pitching my 223 used in auto loaders after 4 full power loads. The brass can last much longer in bolt actions.

 

[kbm6893]

Thanks for the replies. I won’t be shooting high volumes so I can’t imagine loading a piece of brass more than 3 times max. I will never let it get anywhere near max length of 1.760.

What I am trying to say is if the brass is say 1.745 and it doesn’t contact the cutter because I have that set to 1.747 or so, the brass is still safe to load? So if it’s 1.743 and it doesn’t contact the cutter I know it’s not too long and just move along? I still plan to measure every piece after it’s trimmed. And yes, I know to chamfer and deburr.

As for the length changing, I found that if it is not exactly centered on the jaws of the caliper the reading can slightly change. Also how firmly I am sliding the jaws together on the piece of brass.

I am very careful with reloading. Truth is, if the only real concern is brass that is over 1.760 and brass that is under 1.750 by .008 so it measure 1.742 is still safe to load than I am happy with that. Once I have all my brass ready to go I’ll load up a few and test them out.

I’ve read 1.745 is a good minimum, so should I toss anything under that?

 

[LostintheOzone]

Forget the calipers. I use one of these to determine if the case needs to be trimmed after you decap and size.

Case Gage

There's a step on the gauge (1.76) that will tell you if you need to trim the case. I usually trim it while the case is in my hand if it needs it. If not it goes into the container of in-spec cases. If it does get trimmed it goes into the same container. All of it will be 1.76 untrimmed or 1.75 if trimmed.

The gauge will also tell you if it's under 1.75. I just throw those away because they're out of spec.

One other benefit of this gauge is it will tell you if your die is set correctly.

 

[Ivan the Butcher]

I have had a number of different case trimmers. (Hornady, RCBS, Redding, & Forrester) Except for the type of trimmers like Lee sells, I ALWAYS start with a MINIMUM length case and set the finish length to that. I have the case length permanently written on that case. If you want to trim to a longer or shorter case length, That is fine, within reason. (I have a match chamber Bench Rest gun with a chamber that is .002 shorter than the listed minimum, so I trim .005 below Minimum!) Once you have established that case, that is your "Slave" set it aside, so you can use it next time. I put mine in the die box, one of my friends puts his in storage with the trimmer. Whatever you think would work best for you.

There is one friend that has a L.E.Wilson case trimmer set for each length and Loctite's them permanently. They are set at 1.495"(39mm), 1.995"(51mm), 2.245"(57mm), and 2.495"(63mm). He doesn't load anything that isn't one of those lengths! In his opinion 223 for AR's isn't worth trimming! (it is 45mm).

Ivan

 

[kbm6893]

Forget the calipers. I use one of these to determine if the case needs to be trimmed after you decap and size.

Case Gage

There's a step on the gauge (1.76) that will tell you if you need to trim the case. I usually trim it while the case is in my hand if it needs it. If not it goes into the container of in-spec cases. If it does get trimmed it goes into the same container. All of it will be 1.76 untrimmed or 1.75 if trimmed.

The gauge will also tell you if it's under 1.75. I just throw those away because they're out of spec.

One other benefit of this gauge is it will tell you if your die is set correctly.

Jeez. I’m beginning to wonder if I made a mistake getting into reloading rifle. Pistol is so much easier. I already bought a Lyman case gauge. It says if the case fits in its good to go. I just want to produce safe plinking loads for my AR. I know not to go over 1.760. I’m happy to toss anything less than 1.745. I just want to be safe. My reloading technique is pretty basic but safe. Worrying if I am under length by .004” is not something I feel like dealing with.

 

[BC38]

Jeez. I’m beginning to wonder if I made a mistake getting into reloading rifle. Pistol is so much easier. I already bought a Lyman case gauge. It says if the case fits in its good to go. I just want to produce safe plinking loads for my AR. I know not to go over 1.760. I’m happy to toss anything less than 1.745. I just want to be safe. My reloading technique is pretty basic but safe. Worrying if I am under length by .004” is not something I feel like dealing with.

Don't get discouraged man. You've had a dozen people tell you 1.745" to 1.760" is OK and one contrary opinion that anything less than 1.75" should be tossed because it's "out of spec".

I'm not sure exactly whose "spec" that would be since I've never seen a published minimum spec of 1.75" - have you?

Anyway, don't let one outlier opinion get you flustered. Take it with a grain of salt. You're not going to be doing anything unsafe by using brass that is 1.745".

Think about it: cases get longer (not shorter) when they are fired and re-sized, so if it is shorter than 1.745" then it was almost certainly even shorter than that when it was fired the first time - and it didn't blow up a gun, right?

While reloading needs to be done largely "by the book" (a.k.a. following published data & specs) it also requires application of common sense.

 

[LostintheOzone]

Jeez. I’m beginning to wonder if I made a mistake getting into reloading rifle. Pistol is so much easier. I already bought a Lyman case gauge. It says if the case fits in its good to go. I just want to produce safe plinking loads for my AR. I know not to go over 1.760. I’m happy to toss anything less than 1.745. I just want to be safe. My reloading technique is pretty basic but safe. Worrying if I am under length by .004” is not something I feel like dealing with.

If it's under 1.75, say 1.745 it isn't a problem. If you're using a case gauge it's going to be difficult to know exactly how much under 1.75 it is so I just toss those. I reload a lot of .223 and I have thousands of range cases so I'm not losing any sleep over a few hundred cases. If you want to measure everyone with a caliper you should probably do that but it's too time consuming for me. Sorry, not trying to discourage anyone. I thought rifle was going to be harder than pistol but it isn't. You just need to go slow and feel good about your methods. All good.

 

[LostintheOzone]

Don't get discouraged man. You've had a dozen people tell you 1.745" to 1.760" is OK and one contrary opinion that anything less than 1.75" should be tossed because it's "out of spec".

I'm not sure exactly whose "spec" that would be since I've never seen a published minimum spec of 1.75" - have you?

Anyway, don't let one outlier opinion get you flustered. Take it with a grain of salt. You're not going to be doing anything unsafe by using brass that is 1.745".

Think about it: cases get longer (not shorter) when they are fired and re-sized, so if it is shorter than 1.745" then it was almost certainly even shorter than that when it was fired the first time - and it didn't blow up a gun, right?

While reloading needs to be done largely "by the book" (a.k.a. following published data & specs) it also requires application of common sense.

I've seen some of those 1.74 cases from the range bucket but that doesn't mean you have to use them. I round up to the nearest 0.00". It's either 1.75 or somebody's mistake. I'll just leave it at that.

 

[zeke]

After resizing and separating makes of range pick ups, was left with a batch of fed brass that was shorter than the rest. They all got trimmed to 1.740, and functioned just fine with bullets seated to their normal length. If you are wedded to seating your bullets to the cannelure, your accuracy may suffer and may need to make very small adj to powder charge.

Shorter case length is not near the problem as longer than spec can be.

 

[BC38]

I've seen some of those 1.74 cases from the range bucket but that doesn't mean you have to use them. I round up to the nearest 0.00". It's either 1.75 or somebody's mistake. I'll just leave it at that.

Then does that mean that the 1.75" minimum is your spec? Did you read it somewhere or learn it somewhere or just select that as your minimum?

No insult intended, just curious, because you were the only one confusing the new guy by throwing out a "spec" that was at odds with what everyone else said. So I was just wondering exactly where it came from.

 

[Westie1]

Actually, i wouldn't worry about tossing the shorter cases. A little research as to what is the SAAMI spec on case length will show that the official SAAMI spec is 1.760 - 0.030. So you could go as short as 1.730 and still be in spec. See page 68 in below.

https://saami.org/wp-content/upload...99.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

 

[growr]

Seems like a lot of angst over a miniscule amount......I don't overthink it and harvest thousands of praire dogs every year with range pickup brass that I trim and move on, with no complaint about the casing being too short......they all gauge good on my Dillon Case gauge...whatever that mics out to be.

Randy

 

[BC38]

Actually, i wouldn't worry about tossing the shorter cases. A little research as to what is the SAAMI spec on case length will show that the official SAAMI spec is 1.760 - 0.030. So you could go as short as 1.730 and still be in spec. See page 68 in below.

https://saami.org/wp-content/upload...99.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

Well ya' can't argue with SAAMI, so I guess that is a pretty definitive answer.

For what it's worth, in a field like reloading where even a couple of thousandths of an inch can make a difference, I wouldn't exactly call 15-30 thousandths minuscule.

 

[Wise_A]

But what about the pile that is less than 1.748? Obviously don’t trim but should I still load them? Is there a minimum case length? Don’t see anything listed.

And I wasn’t clear on setting the trimmer. I plan to use a case that’s already the length to get me in the ballpark and then trim and measure. A few videos on YouTube I saw say to use that as a starting part. Put the case in so it just barely touches the cutter and go from there.

They fired fine the first time, didn't they? Yeah, just shoot 'em. There is a practical "minimum case length", but you're not going to see it unless you go crazy with the trimmer. And it's not uncommon to see newly-manufactured brass from reputable makers be under-length. I've happily used such brass in bolt guns to shoot down to the .25-.35MOA range.

RE: trim length setting, I always start with a case I'm going to trim--naturally, it's over-length--and just start trimming and measuring. I'm using an LE Wilson bench trimmer.

 

[Wise_A]

Would certainly not advise waiting till pretty much all your brass is way over the max trim depth.

Not maximum length--trim-to. And largely, I'm trimming at that point just to even them all up.

I’m beginning to wonder if I made a mistake getting into reloading rifle. Pistol is so much easier.

It can be, but that's half the fun! It's also worth noting that the amount of effort you expend should be dictated by your expectations. Trickling each charge makes sense when you're chasing .5 or .25MOA groups, but I sure wouldn't recommend it if you just want to take out your AR or Mini-14 for some 50-yard plinking.

But that's why I like rifle, I think. With pistol, I care somewhat about ammo cost and how much time it takes. But I shoot such small volumes of rifle that I can pull out all the stops, focus on making great ammunition, and see the results.

(I have a match chamber Bench Rest gun with a chamber that is .002 shorter than the listed minimum, so I trim .005 below Minimum!)

Ivan has all the cool stuff.