308 cases

I

iagbarrb

New member
Hy
I compete in benchrest with .223 with very nice results. Reload .223 allmost one year. Fot 2016 I also want to compete with 308 shooting 300 yards wirh a steyr ssg69.
Have no experience with 308, but have seen that in some rifles some cases break and stay in the chamber. Have seen dome shooters having enormous difficulties to remuve this shells.
As I live in a country where getting good shells is very difficult, I might have to reuse my brass plenty of times.
Really need some advice about how many times I can use my brass, and how to care the cases I have.
Thanks a lot.
 
And then the rifle reminded him of the 303 British rifles with the rear locking lugs. I am the fan of the short hook up; I want the lugs in front. I do not like the ideal the long bolt becoming a long support column. I like the ideal of of having lugs in the front and rear and I believe lugs in front and rear is a better ideal.

Cutting down on case travel with the lugs in the rear may not be possible. Then there is that other part about cutting down on case travel, I am the fan of ‘the claw’, I want control feed. I have control feed that does not operate the way Mauser designed it. I have push feed rifles that work and cut down on case travel.

F. Guffey
 
The way to make brass live a long time with high pressure use, is to follow the 6mmPPC benchrest example. The necks of the loaded ammo have so little clearance that during firing, the bass never reaches the elastic limit. No resizing is needed. This is not practical for hunting or war, but benchrest can be kept clean and controlled.

I first read this info in 2002. I hope Al is still alive:


http://www.varmintal.com/arelo.htm

NECK TURNING FOR CUSTOM-CHAMBERED RIFLES.... For my rifles with tight-necked custom chambers, I use "fitted neck" cases. Once made, these "fitted neck" cases need no resizing. All that is required for reloading is to clean the primer pocket, clean the neck ID, reprime, throw the powder charge, and seat the bullet. These rifles have chamber neck diameters so small that I can't close the bolt on factory ammunition. It took a while to figure out how to reliably make "fitted neck" cases and it cost me quite a few good pieces of brass in the learning process. The first step is to turn the necks on 3 or 4 sacrificial cases so that there is approximately 0.005 inch of neck clearance with a bullet seated. Load a standard load and fire-form these cases. Carefully measure the neck diameter of these fired cases and record this diameter. I call it the "spring back" diameter. This diameter is actually the diameter the brass neck will spring back from elastically after being forced against the rifle chamber's neck diameter, including the elastic expansion of the chamber itself. The difference between the barrel's chamber neck diameter and this fire-formed case neck's "spring back" diameter is usually about 0.0013 inch to 0.0015 inch. This spring back is for the .224 to .243 calibers.
 
The nice thing about the 308 W chamber is not recognized until the reloader realizes the neck in the chamber is generous. When that happens the reloader can do the opposite when given bench rester advise.

Then I will assume you missed the part about the rear locking lugs.

F. Guffey
 
Short case life resulting in case separation in a bolt rifle is most likely due to excessive clearance between the case shoulder and the chamber shoulder. Call the distance between base and shoulder "cartridge headspace". SAAMI does not have a definition for this, one of the moderators called SAAMI and they have no other name than "alpha-numeric", neither the word nor the definition is on their web page. SAAMI is not particularly interested in supporting reloaders as the association wants to sell new brass and ammunition, they lose profit when shooters reload.

Your rifle chamber has headspace, it is the distance between bolt face and cartridge seating surface in the chamber. Gun headspace and cartridge headspace must be considered in reloading. If the cartridge headspace, that is the distance from base to shoulder seating surface, is larger than the chamber headspace, the cartridge will be an interference fit. You may not be able to close the bolt and the case may be jammed in the chamber so tightly that it won't extract after firing. If the cartridge headspace, that is the distance from base to shoulder seating surface, is too short, a condition which creates a lot of clearance between the case shoulder and the chamber shoulder, the most common result is case separation. Short cases can also misfire as the firing pin can't hit the primer.

I recommend on the average a clearance of 0.003" between the case shoulder and the chamber. Clearances on the order of 0.006" will result in case separation. It is therefore very important to control these parameters. There are ways to measure shoulder set back after sizing, and this web page, will show you how to do that:

Extending Cartridge Case Life

http://www.realguns.com/Commentary/comar46.htm
 
SAAMI does not have a definition for this, one of the moderators called SAAMI and they have no other name than "alpha-numeric",
Click to expand...

There have been at least three members call SAAMI, two of them are very prolific posters on various forums. It seems the members insisted every tool was a head space tool and they insisted everything had head space. I could not find the symbol for head space on the case drawings so I spoke where SAAMI spoke and was silent on when they were silent. For most it is impossible to even think the case does not have head space after years of declaring it did.

Like it was easier to get me to agree with them, I was asked t agree, it was suggested the reloading world would benefit. My answer was not only no, it was a BIG CANJU NO.

F. Guffey
 
I can't believe this is still an issue . I believe it was not that members wanted anyone to stop believing in the fact head space is only measured in the chamber . The thing I brought up was that it was easier and quicker to say case head space ( or cartridge ) when referring to the length from case head to datum point which is a measured area somewhere around the center of the cases shoulder .

In this day in age of , IMO , OMG , TMI , etc . What's so bad about saying

"Cartridge head space"

rather then

" The length from case head to datum point which is a measured area somewhere around the center of the cases shoulder "

As many times as that info needs to be explained and written out on forums . To me it does not seem unreasonable to want a better way to refer to that measurement . Most experienced reloaders know what the term cartridge head space represents . If we then get a question as to what we are referring to . We can then write it out in long hand .

Maybe it would be easier to think of cartridge/case head space as a acronym or abbreviation for that referenced information . :)

To the OP , here are two ways to measure that distance on a 308 case . Ignore the actual measurements you see . the photos are only to show how to make the measurement/comparison .

Hornady cartridge headspace gage/comparator
YN8EJj.jpg


Using a empty 40 S&W case with primer removed
N0gFeR.jpg


You then compare your fire formed cases to the cases you size using either method . You want your sized cases to be .002 to .003 shorter then your fire formed cases .
 
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I can't believe this is still an issue . I believe it was not that members wanted anyone to stop believing in the fact head space is only measured in the chamber . The thing I brought up was that it was easier and quicker to say case head space ( or cartridge ) when referring to the length from case head to datum point which is a measured area somewhere around the center of the cases shoulder .

In this day in age of , IMO , OMG , TMI , etc . What's so bad about saying

"Cartridge head space"

rather then

" The length from case head to datum point which is a measured area somewhere around the center of the cases shoulder "
Click to expand...
It seems to be an issue for only one poster. Not having a SAAMI definition for "cartridge headspace" allows this poster to start a narcissist, self serving, soliloquy about "How great I art!", and,

I have datums,

lovely , lovely datums,

I have datums to last me for my life
 
Thank you very much for the posts.
I am starting to have real precise impacts at long distances.
Reloading 308 is not as easy as 223 but by reloading 308 I have made great improvement in my 223 as well.
 
" The length from case head to datum point which is a measured area somewhere around the center of the cases shoulder "
Click to expand...

Because the datum for the 8mm57, 30/06, 280 Remington, 270 Winchester 25/06 etc.. Is the same for all cartridges listed, it is not somewhere around the center of the case shoulder; it is located with a datum of .375".

Keeping up with a datum diameter is not a problem for me and when I am using a round hole as a comparator all I am required to do is measure before and again after.

Short case life resulting in case separation in a bolt rifle is most likely due to excessive clearance between the case shoulder and the chamber shoulder. Call the distance between base and shoulder "cartridge headspace". SAAMI does not have a definition for this, one of the moderators called SAAMI and they have no other name than "alpha-numeric", neither the word nor the definition is on their web page. SAAMI is not particularly interested in supporting reloaders as the association wants to sell new brass and ammunition; they lose profit when shooters reload.
Click to expand...

Sounds like a conspiracy theory, I did not call SAAMI, and I question the motivie for calling. SAAMI does not list case head space for the case because the case does not have head space. I do not know what was discussed by the reloader that insisted the case had head space but I can only imagine he listed his pedigree in an effort to be taken serious. And it would have pleased me if he called SAAMI and told them about what or who) provoked him to call.

Call the distance between base and shoulder "cartridge headspace”
Click to expand...

That would be rather silly when SAAMI has a name for the clearance between the shoulder of the case and chamber shoulder; they identify the clearance between the two shoulders as “CLEARENCE”.

F. Guffey
 
And there was that silly person that called RCBS and reported me for claiming the Rock Chucker did not cam over. RCBS gave him a phone number with a name of a technical person. There was nothing I could do to motive the silly person to push himself away from the keyboard long enough to measure ram travel on the Rock Chucker. I have to assume he had one.

What ever the Rock Chucker does when the ram is raised without a case in the shell holder is ugly when the linkage goes into a bind.

No case in the shell holder creates a no load condition. It is impossible for a reloader to grasp the ideal the case aligns the shell holder with the die and without the case the ram is kicked forward at the top and back at the bottom.

F. Guffey
 
http://www.saami.org/PubResources/CC_Drawings/Rifle/270 Winchester.pdf

Open the link; notice the chamber has a symbol for head space. The symbol is not used on the case. We have had members of various reloading forms call SAAMI to inform them of the mistake. Members talk to me like that all the time, I can only guess SAAMI did not take them seriously because I notice there is no update and the head space symbol for the case is not used because the case does not have head space.

F. Guffey
 
308 auto loaders are harsh on brass, especially if the brass is reloaded 3+ times.

If you're going to stretch the life of your brass, you need one of these, a broken shell extractor. Eventually, you will get a broken case. This thing easily removes any broken shell without damaging the barrel or chamber.

This version of the broken shell extractor works miracles. This one was given to me by an armorer.



It catches the broken shell like this

 
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