October 18, 2012, 04:22 PM | #1 |
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30-06 dimensions?
Hello folks, I'm new to reloading I pretty much finished setting up my tools, I'm using a Lyman turret press to reload 30-06 and 9mm. For now I'm starting with the rifle rounds as they're more expensive and I noticed something peculiar.
The Lyman loading manual says the overall length of a finished 30-06 round should be 3.34" and the internet seems to agree so that's what I've been reloading to but I bought a box of new 30-06 rounds and they are noticeably shorter. They measured 3.19", a difference of 0.15" seemed significant. I was hoping someone might be able to shed some light on this? Thank you |
October 18, 2012, 04:34 PM | #2 |
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"...They measured 3.19", a difference of 0.15" seemed significant. I was hoping someone might be able to shed some light on this?"
Yeah. It's enough to make a guy suspect book OAL isn't all that critical ain't it? Back when I started, hardly any data source made any OAL suggestion at all, we figgered out what would work in our own magizines and chambers and developed our charges at that length; we lived. |
October 19, 2012, 08:56 AM | #3 |
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Yeah. It's enough to make a guy suspect book OAL isn't all that critical ain't it?
Back when I started, hardly any data source made any OAL suggestion at all, we figured out what would work in our own magazines and chambers and developed our charges at that length; we lived. Like we had no body, just ourselves? Then there was Roy Weatherby, opening statement under ‘Long-Throating’, “We throat all our barrels 3/4”....etc..”. I am the fan of the running start, I want my bullets to have a jump, the jump is what Weatherby eludes to in his “We throat all our barrels 3/4” “. statement. Today there are those that start the statement “I like my bullets .002” off the lands” and that is it. No mention of dropping the pressure by moving the bullet out, no mention of seating the bullet out to or against the lands will increase pressure, no mention if the possibility of adding powder after seating the bullet out because! moving the bullet out makes more room for powder, I do not believe in the big inning reloaders had as many bad habits. Blame it on the Internet? “Hello folks, I'm new to reloading I pretty much finished setting up my tools, I'm using a Lyman turret press to reload 30-06 and 9mm. For now I'm starting with the rifle rounds as they're more expensive and I noticed something peculiar” “I am new to reloading....”, You are loading for a chamber you know nothing about, you do not know the length of the chamber from the bolt face to the shoulder of the chamber, you do not know the distance from the bolt face to the rifling. In a Google search “30-06 dimensions?” will automatically trigger responses in +/- measurements of case dimensions. Case dimensions include the length of the case, the length of the case from the head of the case to its shoulder and from the the shoulder of the case to the end of the neck, three different measurements when using a gage like the L. E. Wilson case gage. then there are tools for measuring the MAXIMUM OVERALL LENGTH, COL can have two dimensioned, one being the maximum determined by the length of the magazine the other is determined by length of the chamber from the bolt face to the rifling, Weatherby maximum length was determined by the length of the magazine. Then, before the Internet reloaers got to thinking, the thinking led to reloaders having 300 Win Mag chambers throated (throat lengthened with a reamer), this allowed for more free bore OR by moving the bullet out the reloader increased volumn/space in the case, by the very nature of some reloaders they used up the free bore by increasing the COL and then added powder behind the bullet. I would suggest ignoring Internet reloaders that suggest seating the bullet out to the lands for what ever reason, the most used rational is accuracy, unless there are qualifying statements like moving the bullet out against the lands could increase pressure etc.. F. Guffey |
October 19, 2012, 09:08 AM | #4 |
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The 30-06 started off as a military round for the 1903 Springfield rifle. The COAL involved is for the M1 or M2 loading, which is pretty far out compared to most hunting bullets.
That millions upon millions of 30-06's have been made, and commercial ammo available from 110 to 220 grain projectiles, expect some variety in COAL. Jimro
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October 19, 2012, 08:51 PM | #5 |
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The bullet shape also has some influence on the COAL. I do em pretty long but make sure they go thru the action.
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October 19, 2012, 09:21 PM | #6 |
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Make it easy on yourself
Get some Hornady Spire Point 150s. Seat to the cannelure. Voila.
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October 20, 2012, 01:47 PM | #7 |
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I am still lost on what F Gully was trying to say but.....
COAL has two factors. 1. Where the bullet actually is in relationship to the lands. 2. What your magazine length allows. You did not say what rounds in 30-06 you bought. Use the right book for the bullet you are using, not a generic. Always check multiple sources to be sure and even more so if it does not make sense. Never use specific internet data other than as a guide (this powder worked good with this bullet). Some of those lower grains bullets are so short, that you would have to be way off (shorter) than the maximum allowed COAL or they would not even be in the case. Those will have a listed shorter COAL by the mfg. My Horndby books list 3.17 for 110 and 130 grain bullets in 30-06. This has to do with enough seat depth to hold the bullet right (not all have canelures!) and a safe no pressure spike with the powders used. |
October 20, 2012, 03:53 PM | #8 |
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Mr. Guffey is just pointing out that every chamber is individual, which implies that the cartridge specs for it should really be individual, too, especially if tip top performance in both the velocity and accuracy arenas are among your objectives. The SAAMI specs and military specs (slightly different on tolerances) are really a compromise for mass production that will function in all SAAMI and military spec compliant magazines and chambers, but aren't usually truly optimal in any individual weapon's chamber.
Andrewsky96, Welcome to the forum. What might be of immediate interest and relief to you as a handloading beginner is a quick look at the SAAMI drawing of the .30-06. You'll find the cartridge standard dimensional specification is the upper half of the drawing and the standard chamber specification is the lower half. The COL spec in the cartridge drawing is 2.940" Minimum, to 3.340" Maximum. As long as a cartridge you purchase is somewhere in that range it is complying with the SAAMI standard, and at 3.15", yours certainly are. You have to keep in mind that SAAMI is a manufacturer's association and an ANSI standards organization. As Mr. Guffey's post suggests, their limits are not real world limits as to what you or a custom gunsmith can do under the appropriate circumstances. They are just what a manufacturer must do for cross-compatibility of his guns and ammunition with other maker's ammunition and guns. As the others have pointed out, these limits are mainly to ensure proper feeding from a magazine into a chamber made to SAAMI standards. You can load longer if your throat is long enough to tolerate it and you are willing to accept having to load one at a time if the extra length trips up your magazine. You can load shorter if you are using a very short bullet like sized-down .32 cast wadcutter bullet, but you can't count on those to feed smoothly in all guns. So it just depends on what you are trying to do.
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October 20, 2012, 08:28 PM | #9 | |
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Quote:
Assuming so, it is based on [the] very specific bullet shape peculiar to Hornady bullets in general (very long shank, very short ogive roll-over). Hornady loadbooks take this ogive/OAL into account. Last edited by mehavey; October 20, 2012 at 09:38 PM. |
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October 21, 2012, 03:11 PM | #10 |
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Thank you all for your responses.
Unclenick, thank you for pointing out the SAAMI website, that drawing was very enlightening. To answer those who asked the pre-made rounds I was referencing were Remingtons and the bullets that I am loading are sierra 150 gr spitzers. The manual I am using to reload seems to be fairly informative but it did not point out that the OAL was a maximum and not a standard. |
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