Lee dies...what am I doing wrong???

Hey all,
I've been hand-loading for many years. I unabashedly hopped on the 6mm ARC train when it came by and I haven't looked back. I love this cartridge.
When I hopped on the train, the only available dies I could get my hands on were the LEE 3-die sets. The beauty of the 6ARC, (as you already know, I get it) is that it has a faster twist and can accommodate the longer, higher BC bullets, than say, the oldy but goody, .243 Win.

This is where I'm having issues and am looking for your input:
* When seating the bullet, the top seating screw barely has enough threads to stay in the die body. It's wobbly and I'm getting up to .010" difference in bullet seating depth. I'm using my comparitor to measure the ogive of the bullet, so I know I'm getting accurate readings.
* To overcome the above issue I'm backing the die body off in order to allow more room for the seating screw to go further into the die body. This, however, caused some of my shoulders to crush during bullet seating because they aren't supported.
* As a side note, I have annealed these cases and wonder if that made the brass so soft that it allowed them to crush more easily. About 1:15 crushed. The others took the bullet just fine.

I didn't have this issue before because I was loading to SAAMI specs and seating the bullet deeper, but I'm now trying to dial in my seating depth for optimal accuracy which is much further out than SAAMI, as well as FL sizing with a .005" shoulder bump. I don't think the LEE dies are up to the task. I'm leaning toward a set of RCBS dies. Ideas?

Can you set the die taller in the press?

I had exactly the same issue with my Lee 300RUM die set.
Pulled my hair out….
Only answer for me was to bin them, order non-existent Redding dies and wait. Took 12 months of waiting, but now I can load ANY length I desire.

Can't help with your issue, I never found a resolution.

Cheers.

post a pic and i'll help

also, what press are you using?

depending on the seat (not the adjustable stem) could be the issue, but again need pics of what you have too work with. unscrew the stem so i can see the stem and the seat after you post pics of the die in the press.

Have you contacted Lee to see what they may recommend

Seems odd - just how far out are you trying to seat? I use a Hornady seater for my 6 ARC and haven't had any issues whatsoever.

Back die up so more seating stem threads engaged AND slightly lube your case necks after charged with powder but BEFORE seating bullet.

I m guessing your annealing dried brass/neck out…. No carbon etc left to help lubricate bullet when seating.

Try it and I think you ll be surprised. If still collapsing necks die might be under sizing necks a few too many thousandths.

I had this with Hornady dies. In my experience, it was not the unsupported body -- it's possible that the die is hitting the case.

1. Back the die out
2. Graphite on the inside of your neck
3. Do not do the seating in one stroke
4. Use extremely slow seating
5. Partial stroke, rotate, partial stroke, rotate, complete the seating.

You should call Lee. They may have a different seating stem. I had the opposite problem with a 223 Die and they provided a different stem (14 years ago).

Also try a slightly bigger chamfer inside the case mouth.

i will not go into the problems i,ve had with lee dies and shell holders. but i will not buy anything mad by lee! i needed dies for a 7mm08 and found a set of rcbs like new for 20.00 saturday 11-2-24 at the gun show in harrisburg pa.

For my money Lee's products are A1, simple to use and their customer service is greased lightning if you do have problems.
If your 6mm s the only case you load, cut 1/8" off the flat end of the sliding stem and you should be good to go.
Bad move setting the dies further up in the press as you've discovered .
If and when you go back to saami spec, just put an 1/8" thick piece of metal in the behind the stem to get back to the status quo.