Question about 30-06 brass: Why is factory spec so much longer than handbook specs?

[Heir Kommt Die Sonne]

When I first trimmed my 30-06 brass, I didn't have Calipers yet, I did it by eye and kept the cases specifically long because every factory round i've seen has a really long neck.
After I got the calipers I noticed even factory necks seem to be way too long, and after reloading factory 1st fires without trimming, it won't fit into my chambers.
Every factory brass case of 30-06 I've seen seems to be way longer than necessary? 2.484 Is the minimum length to trim to.

 

[Mk-211]

2.484 is the trim to length, what length were you seeing in your factory brass?
If once fired, they also grew from being once fired, that and not all chambers are the same.

What was your loaded overall length?

 

[Hummer70]

Case length growth depends on multliple things. If you are dealing with factory chambers and factory brass you will most likely see empty cases get longer quickly because most 06 factory ammo down at the base is going to be about .465 diameter and factory chambers are likely to be .471 diameter at the base. Thus you have a big expansion.
Your case expands .006", you size it back down and the case gets longer so you are stuck with case lengths getting long and the web of the case getting thinner.
If you are serious about shooting and plan on rebarreling your rifle when barrel goes out you can take steps that will increase brass life tremendously.
You order a custom chamber reamer that has a base dimension of .467-469 thus when new cases are fired they only expand .002 to .004. You case does not expand so much so when you resize it lasts much longer. Bench rests gunners generally have chambers only .001" larger than the loaded round.

Their necks are also very tight.

Bottom line the less your brass moves on firing the longer it will last.

For instance I have a brass cache for my target 30.06 that has already shot out two barrels and now on their third barrels and I have not lost a one from split neck, case separation etc.

I also use milspec 30.06 brass. I did a test and reloaded and fired a new Match case 157 times and it is
waiting for me to get back and keep on shooting it.

 

[Blue68f100]

2.494" is spec length for the 30-06. Generally max is 0.010" over. Factory cases a lot of time have the brass longer to handle a crimp into a cannelure. Any thing that will chamber will work. Just make sure your not hanging up on the shoulder or base expansion.

Like said the closer you hold the sized brass to your chamber the longer life you will get from your brass. Overly large chambers normally cause the brass to fail if you resize back to min spec. Size to your chamber for better life. If your loading for multiple guns you either have to keep the separate for each gun or size to the tightest one knowing it going to hurt you on the looser chambers.

 

[Rule3]

When I first trimmed my 30-06 brass, I didn't have Calipers yet, I did it by eye and kept the cases specifically long because every factory round i've seen has a really long neck.
After I got the calipers I noticed even factory necks seem to be way too long, and after reloading factory 1st fires without trimming, it won't fit into my chambers.
Every factory brass case of 30-06 I've seen seems to be way longer than necessary? 2.484 Is the minimum length to trim to.

How did you measure and trim without have calipers? A yardstick?
Resize fired brass then measure and trim if needed. Not all factory brass is the same length but still will be within Max length,

 

[Shooterbob]

If it was fired they grow was probably close before firing. I would not ever trim by eye very hard to thousand of an inch by eye .Stay safe

 

[Heir Kommt Die Sonne]

2.494" is spec length for the 30-06. Generally max is 0.010" over. Factory cases a lot of time have the brass longer to handle a crimp into a cannelure. Any thing that will chamber will work. Just make sure your not hanging up on the shoulder or base expansion.

So what I understand, 2.484 is the minimum trim to length which you typically wanna do, and 2.494 being the max trim to length if you're going to trim it beyond that. But the actual absolute max a case can be is 2.504 and the factory cases I'm seeing lend themselves to this longer spec for the purpose of crimping into a cannelure? Because this is what I observed all the cases I examined that were significantly long are from crimped cases.

 

[lordpaxman]

I just happened to have some Winchester 150gn Power Points, and have just fired one. I measured one un-fired from the same box.
Case length before firing, crimped into the cannelure: 2.483”
Case length after firing: 2.485”

 

[Heir Kommt Die Sonne]

I just happened to have some Winchester 150gn Power Points, and have just fired one. I measured one un-fired from the same box.
Case length before firing, crimped into the cannelure: 2.483”
Case length after firing: 2.485”

Maybe I should recheck my calipers, or the brass. The brass I loaded up and which won't chamber because its too long is like 70 years old. Probably has been reloaded before but never trimmed. I need a way to pull the bullets to be sure.

 

[MEHavey]

30-06 SAAMI case length spec is 2.474 (Min) to 2.494 (Max)
https://saami.org/wp-content/uploads/2018/01/206.pdf (p. 95)

I cannot imagine factory at 2.504.
(?)

.

 

[Stevel]

Just a couple of thoughts. When you say once fired brass, you are speaking about once fired in YOUR rifle, right?

Second, you didn't mention resizing the cases, just measuring them. Firing will stretch the whole case, and if you didn't re-size the case when de-priming it could cause the rounds not to fit.

This happened to me when I used brass from an older rifle in a newer rifle with a tighter bore. Full length resizing took care of the issue.

 

[Slamfire]

After I got the calipers I noticed even factory necks seem to be way too long, and after reloading factory 1st fires without trimming, it won't fit into my chambers.

First firing of new brass or factory ammunition the brass always lengthens the most. I have measured new, unfired 30-06 brass, all OK for case length: below max. Fire the stuff and it is always above max.

Why it acts that way, heck if I know. And, when I switch sizing dies and size fired brass, the OAL is inevitably over max. When I was weekly competing in NRA Highpower, reloading the same set of brass after ever match, I noticed that case length growth after sizing pretty much stopped around three to four firings as long as the case was fired in the same chamber and sized with the same die. However, use a different rifle, or size in a different die, and the case always got longer out of the sizing die. I don't know why.

Recently shot in a 100 yard reduced Highpower match. I used 308 LC ammunition I loaded years ago. Fired it in my old trusty M1a. The brass had been sized three times. However I used a new Lyman small base die to size the stuff, as the old Lyman die had worn out. I trim cases to 2.800" plus or minus, those cases were trimmed to 2.800", and I expected only a couple of thousandths of case growth, if that. Instead every case sized in that new Lyman die was above max. No idea why that happens.

The fact of the matter is, new brass grows the most after its first firing, and the stuff is always above max. This will cause pressure problems if/when the case neck is pinched in the throat.

 

[Heir Kommt Die Sonne]

Second, you didn't mention resizing the cases, just measuring them. Firing will stretch the whole case, and if you didn't re-size the case when de-priming it could cause the rounds not to fit.

I have vintage 30-06 dies, Ideal make I believe. Probably from the 50s or 60s. Using vintage brass I found, some of them dating to the early 40s.
After full length sizing them, I noticed they were longer than usual (this was a little before I got calipers) so I trimmed them on my Herters case trimmer. I chamfered them, then procedded to load them.
Using bulk 150 grain .308 FMJ bullets, I seated them down to the cannelure but this happened.

The case neck crumbled up, This only happened to me once before to .303 brass that I never trimmed either. So my guess is this is a symptom of brass that's still over sized. At this time I finally bought calipers, measured the rest of the brass and I remember it came out to 2.5?? to 2.6?? but it still was shorter than factory 30.06 I had laying around so I loaded the rest of the batch, loading before the neck reached the cannelure so it didn't crumble up.

My only guess is my calipers weren't zeroed correctly at that time.

BRASS CASE CRUMBLED UP WHEN I SEATED THE BULLET

• Heir Kommt Die Sonne
• Dec 7, 2022
• 7

The mass produced bullet but this shouldn't have happened

After loading all those, it was a big mistake because none of them fit in any of my rifles.

 

[Stevel]

Duplicate. Forgot photo.

 

[Stevel]

Wow. That's quite a crumple.
1. Make sure your neck sizer / carbide primer pin (yellow circle) is not to low. When you set this turn it up so it doesn't show below they die. Place a shell in the shell holder and raise it all the way up. Then screw the die down until it seats on the case, then another little bit. Then, screw the neck sizer / carbide pin down until it pops the primer out and extends an 1/8 of an inch or so beloe the case.

2. To set the seating die, turn the bullet depth pin (red circle) all the way up. The, with a sized case in the press raise it all the way up. Then screw in the seating die until it just touches the case, then another 1/8 to 1/4 turn and lock it in place.

3. Lower the case, place a bullet on it and raise it all the way up. Screw in the bullet seating pin until it touches the bullet. Lower the case and turn the bullet seatings pin down an 1/8 of an inch and raise the case again check the depth. Keep lowering the seating pin until the cannula is at the top of the case. A short press on your handle should crimp it.

Sorry if you already know this. I ran into a similar problem before and the above advice from someone solved it. Just looks like the sizing die isn't going all the way down. Neither is your bullet seater.

 

[Heir Kommt Die Sonne]

Sorry if you already know this. I ran into a similar problem before and the above advice from someone solved it. Just looks like the sizing die isn't going all the way down. Neither is your bullet seater.

No it's fine. I already knew all this but it's already good to post reviews of even the most simplest tasks here, to assist other people if they encounter the same problem.
My dies aren't RCBS, they're vintage Lyman/Ideal and they seated other bullets down properly before. My first batch that was made with once fired brass worked just fine. My only guess is it's a trimming issue, either with my older trimmer adding too much pressure (and somehow bending the necks slightly) or it's a problem with them being still too long, like I have encountered with the .303 cases before.
It wouldn't help to reevaluate how deep the die is seated in the press however, that is a good suggestion. I'll readjust it for future loadings, after as well paying real close attention to my trimming methods.

Btw: Although I bought the herters trimmer at a good deal earlier this year, I was looking in my closet that had my surplus reloading stuff and turns out I bought a RCBS case trimmer years ago. The stuff you forget you have, it's like a happy merry christmas.

 

[lordpaxman]

After loading all those, it was a big mistake because none of them fit in any of my rifles.

I used to load without calipers, way back when, but everything was by feel. A set of calipers you can rely on really helps. I’d go back to square one and check chambering on re-sized cases, and also checking max OAL for your rifles. If you’ve successfully reloaded them before, you should be able to repeat it. Crumpled cases can be a few things but for me it occurs when the roll crimp kicks in too early in the seat/crimp cycle.

 

[Heir Kommt Die Sonne]

I used to load without calipers, way back when, but everything was by feel. A set of calipers you can rely on really helps. I’d go back to square one and check chambering on re-sized cases, and also checking max OAL for your rifles. If you’ve successfully reloaded them before, you should be able to repeat it. Crumpled cases can be a few things but for me it occurs when the roll crimp kicks in too early in the seat/crimp cycle.

Yeah maybe its' different for all of us. I really think mine is a situation of not being fully trimmed properly And/or the old herters trimmer just messed up the necks in some way.
I'm going to take extra caution when trimming and prepping cases from now on. As if it isn't a pain enough (but thats part of the fun)

 

[illinoisburt]

That's a classic case of the seating die turned into the press too far and the crimping step ring inside engaged too early in the stroke of the handle. Really simply test is to carefully run an empty case into the seating die without a bullet -- if it makes contact before the handle is all the way down the die needs to be readjusted. Follow #Stevel's instructions above.

** Referring to the crumpled case