My head is about to explode

[Tnc]

Reloading for my 6.5CM. Once fired Prime brass. Fired in my rifle. Deprime and neck size only with Lee collet neck sizer. Empty brass chambers in my rifle just fine. Prime, powder and seat Berger 130 hybrid to 2.750 OAL. Same as prime factory OAL. Bolt won’t close. Seat a little deeper. Bolt won’t close. Had to seat the bullet to 2.580! OAL before bolt would close.
So. I take a piece of brass and Full Length resize it. Seat a bullet to 2.750 OAL and the bolt closes like butter.
Obviously I have a problem neck sizing but what the fuck is it? I set up the neck sizing die exactly per the instructions.

 

[TheGerman]

What bullet is in the case you measured to get OAL? Sounds like two different bullets and the 130 hybrids you are trying to load hit the rifling where the original bullet was designed differently.

Have you measured where your rifling starts in relation to where your seated 130 hybrid sits?

 

[Tnc]

I measured Prime factory 130 grain. I believe it’s the Norma bullet. Not positive. They are definitely different bullets and I understand the bergers are longer. I have not measured the rifling. I colored the bullets with a sharpie and I was hitting the rifling. I just don’t understand why it would only do this with neck sizing but not with FL sizing. I can’t wrap my head around it. The sizing is the only difference

 

[TheGerman]

What's the difference in the shoulder measurement when you neck size, to when you FL size against what a fired case measures?

 

[delfuego]

I have gotten to post this twice in a month!



Also make sure you own good calipers and bump gauges.

 

[Tnc]

Fired case at shoulder is .461-.462
Full length resized case at shoulder is .459
Prime factory case at shoulder is .460

And great video delfuego. I’m starting to agree with him

 

[delfuego]

I bump my case 2-4 thousands from a fired case usually. That allows the bolt to close easily and gives me a little extra room for dirt and dust at matches. I would keep one fired piece, label it and keep it separate from the others. Also measure and record the case necks, loaded Prime, a fired case, a FL sized case and one you loaded. This will give you an idea of your neck tension and the chamber of your rifle. 2 thousand neck tension is a good place to start. It can also let you know if you need to change your bushings, hone your dies or turn your necks.

 

[MachoKing]

I used to neck size. Then I went to jack another round in to finish the job on an elk and guess what...it wouldn't chamber.

 

[Tnc]

Yeah. I’ve been reloading for about 10 years now. I’ve always FL sized. Just decided to try neck sizing and I think it’ll be short lived

 

[TimeWillTell]

Agree with what's been said: you need to bump the shoulder.

 

[Tnc]

Thanks for replies