Cant push the shoulder back on my LC .308 brass

[10mmShooter]

Okay I need some help, I have read so much about proper headspace that I have several gauges and what they are telling me is very frustrating.

You can see the RCBS precision mic gauge and the Wilson headspace gauge with a .308 case in it

You can see my Redding big boss press with RCBS .308 dies in it. I have the sizing die run all the way so it contacts the shellholder, but I'm still not able to push the shoulder back far enough to pass on the Wilson gauge.

Unfortunately I cant seem to push the shoulder back on my Lake City brass enough to have either gauge show proper headspace, actually the shoulder shows no movement at all when trying to resize the LC brass, the RCBS precision mic shows most of the 1x fired LC brass to +008-+.015 over the SAAMI spec clearly fired in a loose chamber M60/M240B. Remington brass fired out of my M1a shows +.006 over spec. So I need move the LC should back a fair bit.

Any suggestions??

http://www.keithrussell.net/redding.jpg

[dk17hmr]

Are you lubing the inside of the case neck? Sometimes the expanded button with drag the shoulder back out after it is sized.

[Larry Gibson]

Do they chamber in your M1A?

Larry Gibson

[johnly]

I use a 308 trim die that seems to be able to push the shoulder further back than back than my regular 308 FL dies. The other option is to machine .010" off the top of the shell holder.

John

[hiram]

It seems the die was reamed too deep. If you don't want to return the sizing die, another option other than maching .010 off the top of the shellholder is to grind .010 off the bottom of the die. If you grind a little too much just set the die at the height necessary to set the should back.

[Multigunner]

You might get the same effect by shaving the lower surface of the locking ring.

[missionary5155]

Good morning
All the guages are nice.. But the question was asked above.. Does the brass chamber ?
If it chambers why do you want to move the shoulders ?

[high standard 40]

I agree with 5155. Just like some dies may be cut long, chambers can be also. I'd be much more concerned with proper headspace fit in my rifle's chamber than a it's fit in a gauge.

Taking .010" off the lock ring will have no effect. If the die is contacting the shell holder, that's as tight as it gets. But trimming the shell holder will help.

[10mmShooter]

thanks guys, thats what is crazy, the the sized LC brass chambers just fine, I can just drop it in the chamber and it goes fullly in with no resistance at.

My tech card from Springfield says the headspace on my rifle is 1.632, and the guages tell me the brass is not to that spec. But they do drop right in.:veryconfu

[10mmShooter]

Problem sloved, I guess after an night to reflect, I went downstairs and said let me try this cam-over thing before I start grinding dies or shell holders....here what I did

On my press...
1. remove the die
2. fully extend the ram(with no die)
3. insert sizing die and screw down to just touch the shellholder(ram still fully extended)
4. lower ram
5. give the sizing one half turn +180 degree, then lock down.

I guess this is the 'cam over" technique people describe, well I was not convienced thinking if the die is touching thats enough...well actually thats not right...if you adjust as I did at the top of the stroke you can gain a just a bit of mechanial advantage on the brass..[smilie=w:[smilie=w:

Let the loading begin now since I have happy brass [smilie=w:

Thanks again to everyone for the assist, as you can see in the pic, my newer sized brass passes the Wilson guage and my Lyman guage not pictured and the RCBS guage shows -.005... right where I want be.




http://www.keithrussell.net/redding1.jpg

[oneokie]

One can also place a leaf type feeler gauge under the case head in the shellholder to bump the shoulder back.

Have you checked the Wilson gauge with a go gauge? Have you checked the chamber with a no go gauge?

Could be due to stacking of tolerances. It does happen. Quite often.

[Larry Gibson]

10mmshooter

Another suggestion; if you are using an M1A I suggest using the RCBS X-die (regular one as the SB die is not needed with milspec chambers). You will get a much longer case life (16 -20 vs 4 - 6 firings per case) and you will not have to trim. I did an extensive test some years back (I can post if you want) and have been using the X-dies for FL sizing in my M1As since. I also use them in numerous other cartridges for FL sizing, especially in .223, 30-30, 30-06 and 8mm.

Larry Gibson

[Char-Gar]

All dies come with instructions on how to install and adjust them on the press. These instructions tell you to do as you finally did. Every press has linkage and this linkage has play/slop in it. When the dies are adjusted in what you call "cam over", this takes all of the slop out of the linkage and the dies perform as desired.

You problem is a common concern we find on these gun boards. When in doubt, read the instructions!

[Bret4207]

Problem sloved, I guess after an night to reflect, I went downstairs and said let me try this cam-over thing before I start grinding dies or shell holders....here what I did

On my press...
1. remove the die
2. fully extend the ram(with no die)
3. insert sizing die and screw down to just touch the shellholder(ram still fully extended)
4. lower ram
5. give the sizing one half turn +180 degree, then lock down.

I guess this is the 'cam over" technique people describe, well I was not convienced thinking if the die is touching thats enough...well actually thats not right...if you adjust as I did at the top of the stroke you can gain a just a bit of mechanial advantage on the brass..[smilie=w:[smilie=w:

Let the loading begin now since I have happy brass [smilie=w:

Thanks again to everyone for the assist, as you can see in the pic, my newer sized brass passes the Wilson guage and my Lyman guage not pictured and the RCBS guage shows -.005... right where I want be.






Don't feel like the Lone Ranger, I've seen some guys that have been reloading for decades that didn't understand about the "cam over". A case of the written word not being adequate to describe the feel.