Trimming FL sized .223?

Go here - https://saami.org/wp-content/upload...99.4-CFR-Approved-2015-12-14-Posting-Copy.pdf Top part of page is the SAAMI cartridge drawing; lower half of the page is the SAAMI chamber drawing.

223 Remington is on page 68. You will notice that your chamber is cut with space for the case's neck. That is the issue about over long brass - want to stay away from "pinching" the bullet by having brass that is too long. SAAMI calls out the distance from bolt face to end of that chamber neck area as 1.7720". The SAAMI compliant cartridge is 1.760"-.030". I would guesstimate from that, that SAAMI wants about .012" room for a Maximum Length case to "grow" when fired in a SAAMI compliant chamber. It appears various "custom" builders / custom reamer grinders have "better ideas" than what SAAMI publishes - you will likely need to refer to them, if that is what you are shooting.

And, yes - you either want to measure each brass with a caliper before you load it, or you want to use a trim tool that does not require measuring, but takes that case BELOW SAAMI Maximum Length. There is no need that I know of to go to Minimum case length - but you WILL want to know that you start "at" or below "Maximum" case length.
 
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I Dont Care About You said:
Agreed.





8 thou is hardly anything. It is certainly a long way from being dangerous. Case OAL spec has a ton of safety margin. I recently got into loading 303 Brit and when I measured fired cases, some once-fired were easily .050" over.





This is def the way to go.
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.303 brit is not a good example to use as a measuring stick to function well, I have seen them allow head separation on first firing of factory ammo.....dont know what the headspace measurement was but 50 thou wouldnt surprise me at all....doesnt mean it relevant for any other cartridge.
 
fingers284 said:
.303 brit is not a good example to use as a measuring stick to function well, I have seen them allow head separation on first firing of factory ammo.....dont know what the headspace measurement was but 50 thou wouldnt surprise me at all....doesnt mean it relevant for any other cartridge.
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You have gone full red herring here. We were talking about case length, not headspace. 303 Brit is just as susceptible to the dangers of excess case length as any cartridge.

IF we were talking about headspace then you'd be correct .... but we weren't.
 
I might have misunderstood the OP - I thought the concern was about the total length of the case, after firing - that is what gets trimmed off. Has nothing whatever to do with headspace - in the case of the 303 British, the headspace is a small dimension to allow for the case rim to fit - usually from the bolt face to the rear face of the barrel. The 303 British is found on page 107 of that SAAMI document linked above in Post #21. Headspace, for a SAAMI compliant chamber, is .064" Minimum and .071" Maximum - is known that militaries during war time had different standards than that. Over-all cartridge length for a 303 British case is given as 2.222" -.020" - again to be compliant with SAAMI, and militaries at various times might have had different standards to be met.

I believe there are some straight wall hand gun cartridges that rely on the case length for head space purposes, but I do not reload any of them.
 
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You have to measure to know for sure. I believe it depends on what sort of chamber the cartridge was fired in. A loose ar-15 chamber is going to result in a lot more stretch than a precision chambered bolt action rifle. The more the diameter is stretched, that added dimension has to go into length when its sized back down to diameter.
 
Post #25 has it correct - you re-size your cases first, then measure if anything needs to be trimmed for COAL - it can be very misleading to gauge or measure cases before sizing them, although people that set their sizing dies to match their rifle's chamber might not see a bunch of case length increase. About most that I know of would be to be using small base sizing dies and loading for multiple rifles / chambers for same cartridge, at the same time.
 
Potashminer said:
Post #25 has it correct - you re-size your cases first, then measure if anything needs to be trimmed for COAL - it can be very misleading to gauge or measure cases before sizing them, although people that set their sizing dies to match their rifle's chamber might not see a bunch of case length increase. About most that I know of would be to be using small base sizing dies and loading for multiple rifles / chambers for same cartridge, at the same time.
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I thought that was a given, but you never know what people might not know, so thanks for bringing that up.
 
You won't need to trim once or twice fired brass. If you're not crimping it, and only using it for plinking, you might not need to trim it at all. - either way - if yours is just once fired, no trimming will be required unless it was crappy brass to begin with.

With the right tools, trimming is super fast and easy.
 
How often you need to trim .223/5.56 brass depends on the brass. I find almost all Federal brass to be short of the normal 1.750 inch trim to length. Rem brass is typically over the max of 1.760 inch for once fired
Other brass can vary. I find IVI is almost always over the max of 1.760, some times considerably over.
Case trimming is tedious, but an important part of insuring proper function and running in a semi-auto.
Taking any short cuts is not really a good plan.
Either do it right or keep buying factory ammo.
 
Canuck65 said:
You won't need to trim once or twice fired brass. If you're not crimping it, and only using it for plinking, you might not need to trim it at all. - either way - if yours is just once fired, no trimming will be required unless it was crappy brass to begin with.

With the right tools, trimming is super fast and easy.
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Actually no. Remington and IVI almost without exception are almost always over the max case length of 1.760 inches. Some times as long as 1.765 or even 1.775 with IVI brass.
Over length brass is a bigger issue in semi-auto's than bolt guns.
Depends how reliable you need your semi to run and your tolerance for slam fires...
 
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My experience with Federal brass overall is that it is usually short and often doesn't need trimming after first sizing. But there have been exceptions to that rule. Talking 223 plus many other cals. And incase it wasn't mentioned, the cases will grow in length during sizing and need to be measured/trimmed AFTER sizing. I did a ton of them with the Lee case length gauge and chamfer tool in a hand drill. No measuring needed for that setup and it's fast. Dirt cheap too. Lots of great tool choices for everyones least favorite reloading chore.
 
ZREXER said:
Actually no. Remington and IVI almost without exception are almost always over the max case length of 1.760 inches. Some times as long as 1.765 or even 1.775 with IVI brass.
Over length brass is a bigger issue in semi-auto's than bolt guns.
Depends how reliable you need your semi to run and your tolerance for slam fires...
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Ah yes. I may not have read the post carefully enough - for a semi, it is important because you're crimping. I assumed we were talking about a bolt gun.
 
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