Checking neck shoulder thickness

[Aussie_Shooter]

I neck turned a large batch of brass I mislabelled thinking the batches oal was trimmed.
I am now in the position of having neckturned the brass needing to trim to recomended length.
I am concerned I may have cut to deep into the shoulder.
Is there a way of checking the wall thickness at the join?
Do I need to ditch the 300 rounds of lapua brass or should I use them?
If I use them and the neck separates will it damage the chamber/ barrel or is a safety hazard?
What is recomended I do?

 

[Boyd Allen]

Let me get this straight. If you would have trimmed before turning, the necks would have been shorter..right? Was the trimmer mandrel set so as to act as a stop for trimmed cases? If it was, you will have some cases that are not cut as far into the shoulder as they would have been, rather than some cut too far.

 

[Michael Huebner]

I neck turned a large batch of brass I mislabelled thinking the batches oal was trimmed.
I am now in the position of having neckturned the brass needing to trim to recomended length.
I am concerned I may have cut to deep into the shoulder.
Is there a way of checking the wall thickness at the join?
Do I need to ditch the 300 rounds of lapua brass or should I use them?
If I use them and the neck separates will it damage the chamber/ barrel or is a safety hazard?
What is recomended I do?

I recommend you post a photo so we can see how far you have cut into shoulder, before you ditch any brass
Can you feel a lip with your finger nail at that join?
You will not know the tickness at join until fireformed and even then it would be very hard to get a precise measurement

Michael

 

[abintx]

I neck turned a large batch of brass I mislabelled thinking the batches oal was trimmed.
I am now in the position of having neckturned the brass needing to trim to recomended length.
I am concerned I may have cut to deep into the shoulder.
Is there a way of checking the wall thickness at the join?
Do I need to ditch the 300 rounds of Lapua brass or should I use them?
If I use them and the neck separates will it damage the chamber/ barrel or is a safety hazard?
What is recomended I do?

For what it's worth, here are the first few initial steps that I follow prior to turning my 30BR and 6PPC brass that might be helpful in the future:

CASE PREP for NEW BRASS

Headspace

Setup the die WITHOUT using a neck sizing bushing. Size the brass and try it in your rifle without the firing mechanism in the bolt. If the bolt closes normally [falls about halfway on its own, requiring only a little pressure to complete the bolt closure], stop and go to the next step.

Note: If using a dedicated expander [I am], headspace all the brass before going any further. You do NOT have to apply lube to the outside of the case. The case as not yet been expanded so the only part touching the die is the shoulder.

Lock the Die with the Locking Ring

Expand the Neck

Lube the inside of the neck and expander. Expand the neck. Make sure the cases do NOT hit the top of the expander.

Check Overall Case Length

If more than .003” between the cases, Trim all the cases to the lowest number. This will ensure the cut length during the neck turning is consistent.

Champher and Deburr

Turn the Necks

Etcetera.

 

[Wilbur]

Trim and go forward. No, a separated neck will do no more than cause trouble getting it out and perhaps make your group somewhat non-competitive.

Next time, don't cut into the shoulder. That's something that just sounds good and ain't worth a flip.