problem with 308 "LC" brass

[dead_eye]

I am no expert on reload and what I have learned is by word of mouth and reading.
I have just bought a new Savage and I am having trouble with the brass chambering.  I have trimmed the brass to length and used RCBS full length dies on the brass. I have even put a bullet in the case and put a rolled crimp into it and without a bullet.
And before you ask... no, I did not crush the case.
I have miked the case and is showing .470 at the base and .455 by the tapper and case length 2.015.

Any Ideas?

Thank for the help.

[corbanzo]

Is the length to the shoulder and to the neck in spec?  That would most likely hold it up.

[Dave in WV]

Is the Lake City brass once fired? Once fired milspec brass was used in a M-14 or M60 and they have loose chambers unless the M-14 has a match barrel. The brass needs to be full length resized (if once fired) and possibly the shoulder bumped back. One trick you can try is run some of the brass through a .45acp carbide die with the decapping rod removed. This will squeeze the web area of the case only. I have a modified die that the top end has been bored out and I can run loaded ammo through the die if the cases are a bit tight.

[OR-E-Gun Bill]

Maybe too obvious but... will a factory round fit OK?



Did you try laying a flat edge on the area between the red marks to ensure it's flat? No bulge indicated?

Did you try running your die down 1/4 turn? Maybe not fully resizing the brass.

Just guesses...

Bill

[Siskiyou]

I have had no problem with LC74 brass.  Midway recommends using Small Base dies to resize it the first time because some of it has been fired in M60 machine guns.  In my case I am resizing it to .300 Savage.  I have added a step in the process by running the brass into a full length –06 die first and then into a Small Base die, and then trimming the brass to the proper length.  Before priming and loading I chamber each piece of brass in my rifle to insure functioning.

I have used this method for years with x-military brass with good results, but I recently tried the same process to remanufacture commercial .308 brass into .300 Savage brass.  I have run into a similar problem as you are having.  Frankly, I bagged the brass and plan on going back to it on another date.  Before working the brass any more I plan on annealing it.  Every once and a while things that seem to be going right but just do not fit.  In this case after the resizing and trimming process I tried the brass in the intended rifle and the bolt would not close. 

When I go back to this project the first thing I need to do is running a rag and brush into the rifle chamber just in case something has hung up in there.  I do not think that is the case because a factory .300 Savage case functions without a problem.  I have measured the cases and they should be functioning but they are not, that is why my next step is checking out the rifle.  This is the reason I always chamber my resized brass to insure that my loads will function in the rifle.

[beemanbeme]

How is your F/L die set up?  Did you run your ram all the way to the top, screw the die down until it touched, retracted the ram, and then, gave the die another 1/4 to half turn down before locking it?  So that there is a pretty stout cam over action when you run your ram up without a shell in it? When you F/L resize a case, you should not be able to see a gap between the ram and the die.

One last question, when you resize your brass, will the case readidly chamber just being dropped in the chamber and the bolt closed?  If it will, and you're having trouble with your brass with a seated bullet, then you have your bullet seating die set up wrong. You may be mashing the shoulders down with the die bulging the sides of the case.  Back your die body off and extend your bullet seating stem further.

Otherwise if your ammo is in spec and your chamber is clear and you can bring the rifle into battery but with some effort, I'd go ahead and fire the stuff and let it fire form in the rifle.  Then see how the brass does on reloading.  If that doesn't cure things, then it's time to buy a small base die. 

[dead_eye]

Thank everyone for there help first...

corbanzo, the measurement to the shoulder and neck are in spec... 1.560 and 1.712
the angle 20 degrees look right.
Is there a limit to the neck thickness?
If I had that measurement then I could figure if that angle is right with a little algebra.

Dave in WV, yes the brass is once fired. I tried the 45 acp die trick with the decapper removed.. still no go.  I went as far as to start to roll the lip of the case.

OR-E- Gun Bill, no I had not tried factory round... I was thinking the same thing.  Yes, I did run the die the full length. Ram to bottom of the die. 

beemanbeme,The brass is close..the bolt will go forward but will not close. This with a bullet not in the brass.

I think I am with some of you and I am going to have run the brass though some small base dies... I think the way the brass is chambering, it will chamber but the bolt will not close is that the shoulder is the problem....
What does everyone think?



 

[John Traveler]

I second the suggestion that your 7.62 NAT brass was likely fired in a machine gun and is slightly oversized in spec.  The M60 and M240 machine guns are use by the US Military.

The current M240 series machine guns use an adjustable gas regulator collar.  If this collar is adjusted for maximum efficiency i.e. combat in dusty, dirty, hot conditions) the extra extraction force tends to bend the rims, causing an overlength condition.  Full length resizing may or may not correct this.  You description of hard chambering fits that of everlength, insufficiently resized, or bent rim brass.

[Siskiyou]

You might try smoking the case and then seeing where it makes contact in the chamber.

[beemanbeme]

Good point, Siskiyou.
 Blacken the entire case with a magic marker and drop the case in the chamber, then force it firmly into the chamber with the bolt as far as it will go.  Then extract and see when the marks are.  Don't buy the small base dies yet.

[dead_eye]

GOOD IDEA!

used layout die. It showing the pressure right were I though, on the shoulder. The 45 acp die did work for me on doing the shoulder.

Does anyone have a idea on how to push the shoulder back without having to buy a set of small based dies?

[John Traveler]

Small base resizing dies don't push the shoulder back.  They merely provide extra resizing to reduce body and base diameter for easier extraction in semi-auto actions.

Your regular resizing die, properly adjusted to give a solid top dead center stop against the shell holder will set the shoulder back enough to fit a chamber that is in specification.

Another trick, used only when you are certain that your chamber is on the "tight" side, and verified by use of a headspace gage, is to grind a few thousands of an inch off an expendable shell holder.  That will set the shoulder back by the amount you ground off the shell holder.

[dead_eye]

EUREKA!

I thought about what John Traveler said about grinding the shell holder but that still make the die the same length so I took the  length off my die. Chucked it up in the lathe at it two trials at .0005 cut each time. Brass chamber like a dream. I hope my problem help everyone else.

Thank again for brain storm this problem out.

[AtlLaw]

I think they both will accomplish the same thing, but shell holders are a lot cheaper then dies if your not much of a machinist like me.   

[Dave in WV]

Glad you got the problem solved. The shoulder was blown out too far forward in the weapon the brass was fired in and it needed bumped back in tolerance for your rifle.

[Siskiyou]

Over the years I have collected shell holders from Lyman, Lee, RCBS, and Hornady.  I know in some cases the shell holders duplicate others in my collection.  Some years back I got a hand full of shell holders that appear to be thinner then others.  I need to go back and take some measurements.

[dead_eye]

Me bad...
I guess that is right.... I guess that I was worry about taking metal from the shell holder and weaken it.  figuring that there was a lot of extra metal on the die.