.308 minimum oal


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Shruggerx
March 24, 2007, 06:56 PM
Hey guys,
I am new to reloading and new to the site but really excited about starting the whole process. I have a question about the minimum overall length for .308 round with 150gr hornady bullet, with crimp groove.
The Lee crimp die instructions say to seat bullet until 3/4 of the groove width is gone. I seated it and that length is around 2.715. Is that an acceptable number? I know that OAL for .308 is 2.80, but I have no idea what the minimum is.

Will I blow up if I shoot these??:what: :what:

Thank you for your help

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P0832177
March 24, 2007, 07:23 PM
You have demostrated the need for the Hornady Reloading Manual. :cuss: A prudent reloader has manuals for the bullets he loads! Very important! :cuss: What kind of platform are you loading ammo for? If you have properly sized cases then you have no need to crimp ammo you have loaded. Did you develop a load using solid reloading practices? Or did you just pull a load out of the air?

Sharps Shooter
March 24, 2007, 08:08 PM
Howdy Shruggerx and Welcome!:)

"I know that OAL for .308 is 2.80"

Nope. You might THINK the OAL for a .308 is 2.80", but you'd be wrong a lot. The OAL of any particular cartridge, including the .308 Winchester (assuming it IS the .308 Winchester you're asking about) depends on a number of factors, not the least of which is length and overall shape of the bullet. Once you've gained experience, you'll more than likely match the OALs of particular cartridges to the particular rifle you're going to be using them in. What I'm saying is, the OAL of a .308 Winchester is no more 2.80" than a pickup truck is a F-150. Yeah, often it is. Usually it's not.
But to get on with answering your question - I doubt you're going to blow yourself up just because you seated those Hornady bullets until 3/4 of the grooves (cannelures) were inside the cases. Seating bullets too deep can indeed raise pressures to dangerous levels because it leaves less room in the cases - simple physics. But I'm betting you're not doing anything foolish with your first handloads like getting close to maximum listed powder charges and/or using magnum primers when they're not called for. Your post makes you sound like a prudent person.
You'd be wiser though, to get yourself another reloading manual or two. Lee is okay, but you stated you're using Hornady bullets so a Hornady Manual would be a good one to look into. Lyman, Hodgedon and Speer manuals are also good. You might even look into getting one of those "One Book/One Caliber" loadbooks for the .308 Winchester published by Loadbooks USA. But you really do need more than one source (reloading manual) of information when it comes to loading your own ammo.

dmills
March 24, 2007, 09:34 PM
Looking at the "Complete Reloading Manual for the .308 Winchester" under Hornady bullets, I see the following for 150-155 gr. bullets:

30302 SST--2.735
3031 SP--2.735
3033 STSP--2.735
3035 RN--2.520
3037 BT-FMJ--2.780
30312 A-Max--2.800

This is the same information you would find in the "Hornady Manual" for the .308 Win. If you were to check the seating depth of all of the above, it would be substantially the same, with the differences in OAL being due to differences in overall length of the bullets. The critical question is whether the seating depth of the bullet you are using creates a higher than specified cartridge pressure with the powder charge you are using. Those crimp rings on the Hornady bullets are not a guide to seating depth on all cartridges with all powder loads and I do not think that one should be guided by those rings in seating bullets. Consider all of the various .30 caliber cartridges out there and you will see what I mean. You can use the Lee Factory Crimp die on bullets that do not have the crimp rings and you can crimp bullets that have the crimp ring in other locations on the bullet.

I have found no benefit to crimping the .308 Winchester cartridge and have seen no data to suggest that it is necessary, unless you are using a semi-automatic. For a bolt action, I have only seen it recommended by some writers for hunting purposes, assuming the clumsy hunter will be banging the cartridges around in the truck (or where-ever) shortening the OAL.

None of the above answers your question. I have never seen a .308 Win. OAL of 2.715 listed anywhere. Whether that creates a higher than spec. pressure in your situation depends on the powder, amount of powder, case, and probably some other variable of which I am not aware.

Shruggerx
March 24, 2007, 10:29 PM
Thank you for you answers so far I appreciate them.
I don't think I gave you enough info on what I am using.
First off I do own the Loadbooks .308 Winchester guide book with a hornady book on the way. I found the loadbook to be helpful but conflicting in some of the info it provides which is why I need your help.
Second I am using 44gr of Hodgdon Varget powder which is the recommended starting load for the 150gr HPBT Hornady bullet, according to hodgdon and several other realoading books.
Third, did I purchase the wrong bullets for the job. Should I have not gotten bullets with cannelures, are they just the wrong bullet or are they fine just unnecessary? These are being loaded into Winchester brass with cci primers. All with a Lee Anniversary press.

Thank so much for your help.

Charshooter
March 24, 2007, 11:36 PM
Handloading is a long step-by-step process. Most of us have manuals for the bullets we use. It might seem a bit much when you start out, but it is necessary. If you start with Hornedy, I would recommend you use their bullets until you get comfortable. Then if you want to try Sierra, but there manual, or Speer, Nosler, get their manual. Also have some powder manuals. That is part of the hobby, reading lots of manuals. It always helps to have an experienced friend.

Read the post at the top for general readings, it is good advice

Oldsportokie
March 25, 2007, 12:14 AM
Old does not an expert make, but an old reloader must have been caucous enough. In my experience, I have not reloaded any caliber until I have read everything I own in print about that caliber and the planned components. Components have changed with knowledge, sometimes.
For accuracy, I would first put a bullet in an empty case, backwards, Just far enough to stabilize the slug. Then chamber the empty round to full battery. Try to extract the round carefully, and notice that the back of the bullet has engaged the rifleing and was forced depper into the case mouth. To arive at the seating depth of the bullet you can plan on the bullet diameter, at the top of the ogive, can be seated just short of the rifleing. Some loaders suggest 1 tenth of an inch short, others might suggest something less. If the chambered round enguages the rifling it will have higher than normal pressure durring ignition. Lyman reloading manual explains the scenario.
All in all, If you load your ammo using this method and it meets or is less than the Overall length for the particular bullet you have bought, and It feeds from your magazine into the chamber, withpout deforming the bullet tip, and does not jam the reciever, You will have succeeded.
Get other opinions, but thats what I plan for my new deer rifle . All the components are not here yet.

goon
March 25, 2007, 12:57 AM
OAL is a strange animal and so is crimping.
In many rifles you won't need to worry about crimping if your cases are sized properly. The tension of the neck is usually enough to keep the bullet from moving once seated. I have shot handloads through a FAL that weren't crimped because the bullets I was using didn't have a cannelure. The action of the FAL is not the most gentle on ammo but I never had any problems.
I will also confess that I haven't always gotten perfect OAL. I was worried about this at first too but I spoke with some "older" handloaders. They told me that with some bullets, SP types in particular, you will almost never get a perfectly consistent OAL anyway.
So my solution was to do get as close as I could, watch for signs of excess pressure until I knew I was still safe, and not worry TOO much about it. Just worry a little. Just enough to stay safe. And I never go clear to the max because what is the point? Why not give yourself just a little more margin of error? Will that extra 7 fps really make a difference.
Going with exact data is the best way. The more reloading manuals you have the better anyhow because at some point you will wind up with half a box of these bullets that someone gave you that you have never loaded before. And you will want to use them because you already have them and you need some practice before next deer season. So when that day comes and you have six reloading manuals, you will be able to flip to the page with data for those odd few bullets and use them.
After you load enough rounds you start to get a feel for what you can cautiously and safely substitute for what. But it isn't really a good thing to start with.

Oohrah
March 25, 2007, 01:22 AM
Oldsportokie has the right idea and I use that method also. Does it
feed through the magazine. If not, the OAL is too long. If you are
not crimping, ignore the cantalure. If you have a loaded round in that
bullet weight, with simular shape, use it to set up your bullet seating
die. :) :)

4fingermick
March 25, 2007, 07:03 AM
I find that whilst overall length is important, what is more important is where the bullet sits in relation to the lands. If you seat a round nose out the same distance as a sleek spitzer, the round nose might be kissing or engraving the lands, raising pressure more that is safe.

I use a method that I picked up from Nick Harvey, the Technical editor of a few Aussie gun mags and an all round guru as far as hunting, rifle shooting and reloading goes.

I take a flat based bullet and seat it lightly back to front in the case. I then chamber it and gently close the bolt on it. This will cause the bullet to hit the lands and stop and then it will be pushed into the neck of the case.

This will give you a gauge for that rifle. When you load a buttet, ou can seat it and hold it up and compare and it will show you how far off the lands the seated bullet is. Quick and easy.

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