Shoulder Collapse

[redclay]

I am reloading once fired LC 308 brass. Lee Dies and 168grn SMK. About one out of five rounds folds up, just a little ridge around the shoulder but they still have to be pulled and rendered safe and then wasted. You guys have any idea what I should be looking for to reduce the waste of good brass?

 

[chris in va]

IIRC the crimp needs to be backed off a bit. Had the same issue with my 223's.

 

[redclay]

Chris, I am seating these bullets without a crimp.

 

[Walkalong]

Are you sure?

 

[HOWARD J]

When you seat the bullet into the case ---the sholder buckles ???

If this is what happens--your expander ball is not large enuf & when you push on the bullet it is pushing on the case & crushing the sholder

 

[Walkalong]

Try backing the seater die back out some and re-adjust the seater stem down. If this fixes it, the crimp ledge was contacting the case neck.

 

[cfullgraf]

Run an empty case with no bullet up into the die carefully. If it stops before the ram reaches the top of the stroke, you are contacting the crimping ring.

Bakc off the die so the ram goes to the top without the case contacting anything. Then reset the seater stem.

 

[redclay]

The dies are adjusted with ample clearance and the seating die is screwed way down. I have been loading 147grn FMJ (several hundred)and never a failure. To me it seems the SMKs are binding in the case neck. Yes they are vertical before pulling the lever. Would mica help this situation?

 

[Waywatcher]

Definitely sounds like too much crimp.

1. With no die in your press, raise up the cartridge fully.

2. Screw in the seat/crimp die until you feel resistance. Back off 1/4 turn.

3. Adjust seating stem as appropriate.

 

[HOWARD J]

Make sure that hese bullets are 308 or find another bullet or get a larger
expander ball.

 

[rcmodel]

Would mica help this situation?

Probably not.
But chamfering the case mouths probably would.

Still sounds like long cases contacting the crimp portion of the die to me though.

rc

 

[gamestalker]

You sound very sure you aren't crimping, so I would go with chamfering the mouths, and add mica if you still have another occurance.

 

[res45]

Measure the inside neck dia. of a resize case vs. the outside dia. of one of you bullet and see what the difference is. The LC X51 brass is thicker and is probably springing back more than a standard .308 case would giving you a bit more bullet tension making seating harder and possibility collapsing the shoulder on some cases.

 

[Strykervet]

If you are still having problems, do you have a bunch of lube on your rounds? What about up inside the die? You could be getting hydraulic dents. I've gotten this from resizing dies before.

 

[popper]

SMK are boat-tail, but the better LC brass may be getting sized too small, pushing the shoulder down when seating. Mike the expander ball or rod, depending on which Lee set you have. If you are neck-sizing, make sure the sizer is not causing the problem. Check the neck inside for burrs. My Lee rifle dies don't crimp. Lube dents usually are parallel to the case. Another brand of die may allow you to 'pull' the shoulder back out so the case is reuseable. Next time it will be fireformed.

 

[FROGO207]

One other obvious thing that hasn't been asked yet. Are all the brass the same length?? If you have not length sized and chamfered the mouths of them all the same the longer ones would cause problems if the die was crimping/contacting only the long ones. Otherwise I would think that a larger sizing button would help matters. I would measure the bullets and case mouth as stated above.

 

[redclay]

Thanks for all of the suggestions. I have been real busy, went to an AppleSeed shoot this weekend. In response, The cases have all been trimmed for length and the necks have been chamfered slightly inside and out (more on the inside). I clean my brass after sizing so no lube is present. When I get the available time I am going to mike the expander ball and the inside of the neck. This point about LC brass being heavier may have some merit. I did mike the outside of the neck (randomly) before I started chamfering, it was fine. I'll let you know what I find.

 

[chrome_austex]

Are you trimming before or after the resize?

 

[redclay]

Found the problem, my chamfering cutter is very old and worn. It would leave a small ridge inside the case neck at the bottom of the chamfer. This ridge was very small and would show up only occasionally. I suspect it had some thing to do with how hard the brass was. I have a new reamer and every thing is working as it is supposed to.
Lesson learned, Keep your tools sharp!
Thanks for all the input.

 

[gamestalker]

I did that to some .270 brass many years ago, back when I was still wet behind the ears. I discovered I was using too much pressure while reaming and chamfering with a Wilson tool and the Lee, both of which produced a ridge, pretty much as you described.

 

[tomon]

Verify expander ball diameter of .3075.