I'm having trouble loading some .308 rounds and I'm hoping you guys can help.  

I'm using a Hornady L-n-L progressive press to load, but I'm re-sizing and de-priming on an RCBS single stage.  Everything is going fine until I seat the bullet.  During the bullet seating, somehow the case shoulder is crushing down creating a bulge.  







In the group photo, the 3 on the left are ones that I loaded a few weeks ago.  The one on the right is one I loaded last night.  

The second photot is the worst one from a few weeks ago, and the third photo is from last night.  

Let me give you some history that may be relevant to the problem.  

The brass is Hornady match that I bought new from Midway and have loaded one time before.  The bullets are Noslers that Midway sold as blemished due to the canulure.  I'm using the same lot of bullets, same powder and primers, and the same brass as i used before. (the only difference being that the brass has now been once-fired).  As mentioned above, I'm resizing and depriming the brass on a single stage, then using the progressive to load.  I'm using Hornady New Dimension dies (full-length resize die on the single stage, bullet seating/crimp die as the last station on the progressive).  The progressive stations are:  a Lyman neck expanding die, followed by the powder drop, a "powder cop" to confirm a powder charge, and finally the bullet seating/crimp die as the final step.  

The first time I loaded the brass, everything was fine.  All of the crushing has occurred on the second loading.  The dies are all set exactly the way they were during the initial run.

A buddy of mine suggested that I needed to lube the inside of the case neck, which I had not done the first time around.  In fact, I had deliberately cleaned the inside of the case neck the first time around because grains of powder were sticking to the lube when the powder dropped in.  Instead of lubing the case neck, last night I tried lubing the bullets prior to seating them.  The last photo above is the result with the bullet lubed prior to seating/crimping.  

When I tried loading a few weeks ago, I stopped after 5-6 crushed cases in a row.  Last night, with the lubed bullets, I stopped after crushing the first 4 cases.  As noted in the photos, the crushing is not as bad with the bullets lubed, but it's still there.  

Anybody have any ideas?

I 2nd that.Once fired cases are longer and your starting to crimp. I done that a few times when I started loading.

Adjust the seating die.  Place a sized case in the shell holder, raise the ram, screw the die in until you feel the seating die(crimp) make contact with the brass, lower the ram and screw the seating die OUT one full turn.

Case mouths chamfered?

But more often seater set to far down.

Shim the die body up using a 7/8" flat washer and you won't have to readjust your locking ring. The seater stem, however will need to be screwed down.

They all stretched a few hundreths, but they are still in spec according to a Dillon case length gauge.  

I'll re-adjust the die when I get home and try again.  

In thinking about why I havn't had this problem before, it occured to me that the only other bottle-neck cartridge I reload for is .223.  I have a Giraud trimmer set up for .223 and trim the brass each time it gets reloaded, so stretching isn't an issue.

Thanks for all the replies!

Adjust  your seating die per step 12 here http://www.ar15.com/content/page.html?id=469



You got the roll crimping thing going on before the bullet is fully seated

I had this happen when I first started reloading.  I backed the die out and it is fine now.  I am also careful when I get down to the bottom of the handle stroke when seating a bullet and I haven't had it happen again.

I think I found your problem.





.1" = tenths of an inch


.01" = hundredths of an inch


.001" = thousandths of an inch





I presume you really meant thousandths.  Are you certain that the Lyman M die is set properly and is expanding the case mouth? If not, the inside diameter of the neck is too small(presumably you took the expander ball out of the size die?) after resizing. If you didn't size the brass before the initial loading, it was probably large enough to accept the bullet without any problems.





Otherwise, I concur with everyone else that the seater die is screwed in too far.



ETA: measure a bullet and make sure they're .308" and not .311".





 

Yeah, after I posted that it occurred to me that I meant thousandths.  

The good news––Success!

I adjusted the seating/crimp die and everything was fine.  

Thanks for the help.  It's nice to have a place to bounce questions around.

Let me see if I have this straight, you set your dies & loaded some new brass with no issues, then reloaded the once fired brass & are now getting crushed shoulders.  But didn't change anything!  Correct?

If so, What happened is that you set your seating/crimping die to a specific length brass (reguardless of what your gauge implies) then re-loaded them after being fired/stretched.  If the crimp die is set for a specific length brass, the "few hundreds" (wrong measurement by the way) difference is enough extra length that your die is crushing the brass while seating the bullet.  If you use the crimp feature in the seating die, you positively MUST assure consistant brass length every single time you load.  Or, you will get what you got.

Most loaders forego crimping by raising the die until it does not contact the case mouth at all & simply use the die to align & seat the bullet only.  That way you can safely skip trimming every single time & only trim every 2nd or 3rd loading.  If you simply have to crimp, the Lee Factory Crimp die can be a good investment.

Also, don't feel bad, just about every reloader has encountered that little problem at least once.  Some of us more than once.

MLG