Lee collet neck sizer

[Wizbang]

I recently got a prefit barrel for my tikka chambered in 6.5 prc. With all my other rifles I reload for I use a Redding body die, then neck size with the Lee collet die. I really like this process as it produces little to no run out in my case necks as well as gives me consistent neck tension.
When I purchased a Lee collet die for my new 6.5 prc and put it to use, it completely effed up the first case I ran through. It’s hard to explain but it ended up bulging out the case shoulder. Like it pressed down on the neck and pushed the shoulder out. I thought I had set the die up wrong, but this is the 5th die like this I own. Lee calls for 20lbs of pressure for the collet to compress on the mandrel and form the case neck. I tried running it at way less pressure than 20lb. I don’t know where I went wrong?
This is with Peterson brass.

Anyone have any experience with this happening?

 

[Castle Rock]

I use a lot of lee collet dies, and like them a lot.
But I also have a process to tune them up a bit.
When I get one i disassemble them and give them a bit of a polish, deburr and lube.
Maybe the collet is jammed shut on the mandrel

 

[hiker270]

Collet may be jammed as stated before and I also claen up the internals on the die. Not impossible it's the wrong die even though it is packaged as 6.5PRC.

 

[Wizbang]

I use a lot of lee collet dies, and like them a lot.
But I also have a process to tune them up a bit.
When I get one i disassemble them and give them a bit of a polish, deburr and lube.
Maybe the collet is jammed shut on the mandrel

I take mine apart before first use and lube them up pretty good, but have never thought about polishing them up. The mandrel slides easily in and out of the collet.

 

[Wizbang]

Collet may be jammed as stated before and I also claen up the internals on the die. Not impossible it's the wrong die even though it is packaged as 6.5PRC.

It’s stamped 6.5 prc at the bottom of the die.

 

[jfk69]

Like others, I strip them, clean and lube them and clean up any burrs. I love them as well.

 

[MT762]

Dunno if you figured this problem out yet, but have you tried running it at basically no pressure at all? Does it still deform the shoulder even if it's only barely squeezing the neck?

I would probably try dropping a smaller mandrel in and backing the die way off and seeing if you get get any neck resizing with the smaller mandrel...or if the shoulder still gets crushed. But I also have a drawer full of mandrels turned down to various sizes.

Anyway...I digress. If your LCD stilll messes the shoulder up before it gets any neck resizing done, sounds like something went wrong when the collet die was made. I did get a bad one once, but I just tossed it because it was cheaper than sending it back.

My LCD in 6.5 PRC works normally. Lapua brass, but I doubt there is much difference.

 

[coast range]

Sounds like you have a lot of experience with these but I have to ask these were once fired rounds correct? Only time I have heard of an issue like this was when a buddy was trying to just tune up some case mouths on new brass. It crushed the shoulder like you are talking about

 

[Wizbang]

Dunno if you figured this problem out yet, but have you tried running it at basically no pressure at all? Does it still deform the shoulder even if it's only barely squeezing the neck?

I would probably try dropping a smaller mandrel in and backing the die way off and seeing if you get get any neck resizing with the smaller mandrel...or if the shoulder still gets crushed. But I also have a drawer full of mandrels turned down to various sizes.

Anyway...I digress. If your LCD stilll messes the shoulder up before it gets any neck resizing done, sounds like something went wrong when the collet die was made. I did get a bad one once, but I just tossed it because it was cheaper than sending it back.

My LCD in 6.5 PRC works normally. Lapua brass, but I doubt there is much difference.

Funny thing is I did this exact thing this afternoon, minus replacing the mandrel. Barely any pressure at all and it didn’t crush my shoulder while also sizing the neck. Tomorrow I’m going to take the mandrel out and sand/polish it down a little bit to get just a touch more than 2 thou neck tension.

 

[Wizbang]

Sounds like you have a lot of experience with these but I have to ask these were once fired rounds correct? Only time I have heard of an issue like this was when a buddy was trying to just tune up some case mouths on new brass. It crushed the shoulder like you are talking about

It was with once fired brass but I think I have it figured out now.

 

[Balderdash]

Send it back. They'll take care of you. Even if they find it to be in spec, then you'll know.

The only time I had to deal with Lee, and it was because of something I did, they were great.

I use a lot of LCD's. Great concept.