How important is case trimming

[psriley]

How important is case trimming for .223 Remington? I'm going to set up my press to do .223 in quantity. I've been loading .45 ACP in bulk which has really easy case prep...basically straight from the tumbler to the casefeed hopper. I know that, unlike .45 cases, .223 need to be lubed for sizing, but is trimming really necessary for plinking ammo? Not really looking for world-class precision at this point.

Thanks.

[Sydwaiz]

You may not notice anything at first. But after a few firings, especially in a semi-auto, your cases will stretch and may not even chamber.

[Vepr62]

triming

Yes, you need to full lenght size/trim your brass, especially if it was picked up at the range. After you do it once, you can get probably 3-4 loadings out of it without FL sizing/trimming it (only neck sizing), assuming you shoot a bolt action. I resize my brass every time I reload, but I use it in a semi-auto, and I own several guns and the chamber sizes are dimentionlly different from rifle to rifle. So in order to assure proper feeding, I full lenght size all my brass. I dispose of all the brass after 6 loadings. It probably have some life in it, but better be safe than sorry. This only my own experience, and not a general rule. Shoot straight and be safe.
Vasiliy

[Jicko]

1 of all, get a case gauge. Check your cases after you size them before you go further.

When you first start reloading 223.... and if all you have are "once-fired" brass, you will seldom find cases that requires trimming....

So, to start.... you can skip the trimming equipments.... just figure out if you want to acquire those tools once you start seeing "out of spec" (longer than 1.760") brass... (you can always put them aside and use others that are "within spec" first...)

[xrMike]

Does full-length sizing stretch the case out any?

I mean, let's say the case is 1.65" coming out of your gun, is it possible that it will go out of spec (+1.760") when you full-length size it?

[elsolo]

You'll need to measure brass before and after full length resizing in YOUR DIES to know for sure. Not enough lube, or a big expander ball and you can pull a bottleneck case into an straight walled case by accident.

Plan on having to trim all bottleneck brass.

[tujungatoes]

Trimming is (eventually) necessary. with an overly long case the bullet can be further crimped by the throat and cause chamber pressures to rise. In a max or near max load this could cause problems.

Just keep an eye on your case length to make sure they're in spec. better safe than sorry.

[wildcard]

You at the very least should have a set of dial calipers to measure the overall length of your cartridges.. especially when you're setting up your dies. Just use the same toold to take some before and after measurements of your cases and you'll find out! There's always something to trim for my match rifle loads. As for my 44 mag revolver.. I don't even bother.

[psriley]

Thanks for the responses. I guess bottleneck cases are a different animal from straightwall. Guess I'll monitor and trim as necessary.

[jlmurphy]

Most bottleneck rifle cartridges will stretch to fit the chamber when fired, but when resized, all the stretched brass make the case longer. How much it grows each times depends on dimensions of the chamber. The worst possible scenario is the case neck barely fits and crimps the bullet when chambered. Bad.

[50BMGBOB]

A buddy didn't trim for his M1 carbine and had a serious overpressure problem that damaged the gun. Rare, but way take chances. I always trim. If the case doesn't need it and the trimer is set right it won't take any off. Almost as fast as a trim gauge and I know I don't miss any.

[Pthfndr]

Get a Giraud trimmer and just trim it all every time.

It takes less time to trim with his machine than it does to actually check it with a case case.

[Jicko]

If I want to spend THAT much....

And there are other stuff that I want and need much more than an expensive expensive trimmer!

[mousegun]

Get a Lee trimmer. Cheap, fast, and acts like a case length gauge. Chuck it in your Makita and it's really fast!

Checking and trimming bottleneck cases is important to let you know how much your load and resizing is stretching the cases. Lack of attention here can cause a head separation within 5 to 10 reloads.

Pistol cases that heaspace on the mouth need length consistency to assure uniform striking force on the primer. Revolver cases should be trimmed to get consistent crimping. Both are accuracy issues.

[ivanimal]

I think people here are giving good advice. However the MAIN reason that we measure and trim is, if you dont there could be a catastrophic rise in pressure. If the case does not have time to obterate the increase in pressure could be 10,000 psi or more, if you are running hot loads that could be reeeeeeealllly bad.


Trim, its important for safety.

Another issue will be that you will not be able chamber a round due to case length, that would be the least of your worries at that point.