Case trim length 30-06

M

mvorpahl

New member
I have been reloading my own for about 8 years and now i have a friend that wants me to load his 30-06 rounds. The problem i have is that when loading my own or or getting brass from friends, i can control the trim length and do it to the spec i want. He provided me with brass that had been partially prepped by someone else that used to load them for him.

Some of the brass is trimmed shorter than what i know to be the minimum trim length that i use for my own rounds. Below is what i use for mine and what i have gotten from him.

Mine:
Trim length is: 2.484
COL: 3.340

His:
Trim length is: 2.462 to 2.486

Now, the question. Can i use the brass that has been trimmed as short as the lengths listed for his or if shorter than the 2.484, should i toss them?

Thanks
 
Mvorpahl,

Welcome to the forum. Please head over to this thread and introduce yourself to the board.

Actually, yes, you can use the short brass. It's not too short for that. The SAAMI standard for 30-06 case length is 2.474" to 2.494" (max length -0.020"). The military standard is 2.479" to 2.494" (max length -0.015"). However, people don't generally enjoy trimming brass, and when the M1A/M14 were the primary Service Rifle Match guns, it had been observed that military brass in those guns tended to stretch and be ready to retire after 5 loadings (1 by the factory and 4 by the shooter). So, a lot of competitors would just trim their once-fired mil brass back -0.040" from max so they didn't have to trim again before they retired it. Your 2.462" number will put powder fouling a little further back in the chamber neck and will leave bullet cannelures (not an issue with match bullets) sticking out too far to apply crimps reliably. But as long as you don't crimp and don't have very light bullets just barely sticking into the case, I doubt you will notice a performance difference. So what you have won't cause a firing problem – just a potential crimping issue. That said, if you do want to crimp, you will want to make the cases all match the shortest number to start and to seat bullets deeper by that amount to get crimp cannelures to match the case mouth location.

Incidentally, the SAAMI COL spec is 2.940" to 3.340". The 3.340" is the maximum for both SAAMI and Military specs. It is designed around the use of FMJ bullets with 7 caliber tangent ogive nose forms, as the military bullets for combat were. The 3.340" maximum ensures the rounds won't be too long for a 30-06 magazine. Many bullets like a shorter COL The Hornady 150-grain FMJ, for example, has a cannelure that matches the case mouth at about 3.185" COL, and the Sierra tangent ogive match bullets aren't as sharp at the tip as the military FMJ's and are usually recommended to be seated to 3.290". I recommend that unless you are target shooting by single-loading, and especially for feed reliability when hunting or shooting rapid-fire courses in competition, you look up the bullet maker's load data and use whatever COL they call for.

Finally, just as a word of caution, I normally won't load for other people because of the potential liability. I make occasional sharing exceptions among very close friends and relatives who are well aware of the small but real risk potential involved and accept that as their own.
 
I have been reloading my own for about 8 years and now i have a friend that wants me to load his 30-06 rounds.
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OK, fine, he gave you some brass to load.

Did he give you the gun it will be fired from, as well? Because, if he didn't (or won't) I wouldn't make him any ammo.

You have no idea what condition his gun is in. What the tolerances are, and aren't. Without the gun to test the ammo in (and I include test firing) you have no clue if what you load will be safe, or even work at all.

As to bottle necked cases with necks trimmed too short, even a couple tenths too short rarely affects function. As long as there is enough neck to properly hold the bullet it will feed and fire.

Accuracy, is a different matter. One gun might not notice anything, and another might not shoot them worth a damn.
 
You probably won't get any stellar groups using mixed trim lengths like that, and you will probably want to pay attention to the chamber to avoid a carbon ring. Other than that they will still go bang at the end of the day.
 
According to my Hornady manual case length is listed as the following
Max, 2.494
Trim to, 2.484

IMHO trimming shorter, assuming its not crazy short, should not be a huge deal. I know for the RCBS X-die sets they recommend you trim to 0.010 sorter than the listed trim to length. but personally I would try to avoid it if I could.

But as stated the inconsistent lengths could cause consistency issues ad they will effect the grip on the bullet.

Personally I would scrap the ones below 2.484 and salvage what you can. Simply explain that whoever had them messed them up and you can't save them. especially

Other considerations, did you get the rifle to work the loads up? if not I would not touch it. Also, how many times has this brass been fired? Keep an eye out for ejector marks on the bases of the cases, and loose primer pockets.
 
Toss them.
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Personally I would scrap the ones below 2.484 and salvage what you can.
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Having grown up reloading on a budget where every single component was precious, I am very reluctant to toss brass that is still serviceable for something.

I have made 8mm Mauser, 7.7mm Jap and even .308 Win from 06 brass. I've even seen it turned into .22-250 and .45acp.

Even if we're only talking about a box or two, why toss them, TRADE them. Someone will have a use for them, and might have something you find useful. Even if not, considering the shortages we've had, and the ones we might have, why toss anything that will keep and could be used??

If you don't want to load short necks, even for plinker/blaster grade ammo, then don't. Tossing out usable brass is not something I find affordable, but then, I'm cheap. :D
 
After Unclenick weighed in, I went to over trimming my brass so I did not have to mess with it so often.

This is not super precision stuff we are talking about here.

Tossing brass because its a bit short is ridiculous. While its a good question to ask, flip responses on arbitrary numbers is an opinion not worth paying any attention to.

Someone like Unclenick who has an incredible amount of tech stuff in his head he shares is well worth paying attention to.
 
Thanks.

As I mentioned earlier, the SAAMI specs for newly manufactured brass is 2.474 to 2.494 inches. Trim to length recommendations are generally just the middle value of that range. This is based on the idea that if the middle value is targeted, errors or inconsistencies either side of the trim target will have the best chance of not exceeding either end of the range.

The real question is how do they choose the range? The maximum is there to avoid bumping into the end of the chamber neck, which can cause high pressures in some chamber profiles, but what about the minimum? For example, it used to be the 223 Rem also had a 0.020" length range, but between the 1992 standard and the 2015 standard, they increased it to a 0.030" span. I don't know why, but should ask. Obviously, it didn't stop the cartridge from functioning, and I don't know of any reason going to a larger range would stop any other bottleneck rifle cartridge from functioning, as long as you weren't progressive loading to include a crimp. Though, even then you can run short as long as it is reasonably consistent.
 
Read 44AMP's posts carefully and follow them. I never load for anyone without inspecting and measuring the rifle and chamber.
 
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