Neck Sizing with a FL Die

[Mike Matteson]

If you don't cut your neck to thickness, you are not gaining much. That because most necks thickness are not even all the way around. With that you are getting into having a bushing die to do the work, because of the thickness of the neck has been reduced so standard die will not work as well to set neck tension, but generally reduces tension, good or bad is up to what your rifle likes. There is people and I am for one that cuts case thickness to .0013Th. Custom built rifles if the people is thinking about it are having reamers build to take that into account to create a tighter chamber so the expansion is limited and holding the case more inline with the bore. Some of my older rifles, I only cut the necks to a minimum and not to the .0013th.
Now a great many years ago I went to cutting neck thickness to true up the neck setting better in the chamber, not fully understand what was being done or created. I reduced the neck tension on the bullet. The interesting thing was my groups reduce in size. The other was I was using a 308 Norma Mag chamber. I changed to a 300 Win Mag neck sizing die. Theirs a difference between the two and the neck is shorter on the 300 W.M case and to the shoulder is a little longer. So I only size about half of my case neck. I gain two ways. 1. My accuracy increases and my case base separation stopped. Now I loose my cases because of primer pocket getting loose. It's may understanding there is a way to reduce that. I haven't tried it yet. so I can't comment for now. Working your case goes on and on what can or should be done. Hopefully this will help and probable somebody will have sometime to say. There is other items that come into play also.

 

[Rosebud]

For what its worth, whenever I have to pull bullets I just dump the powder then when I reload with new powder or charge weight I seat the bullet and add a light crimp. Just enough to unsure they have mostly the same neck tension. But I'm only doing it for hunting loads. Not looking for super long range shooting. very lite crimp using Lee FCD,one eighth to one quarter turn.

 

[Mikecr]

It's been a while since ive messed with it but it seems like I could also feel a difference when pulling bullets back out of ones I tried to just re seat.

Pulling bullets, pushing bullets,, means nothing about neck tension (what holds onto your bullets).
Bullets are not pushed out of necks on firing. Instead, they're released by a tiny amount of neck expansion away from bearing.
Your bullets at cal. The neck ID is at cal. When the neck expands 1 millionth of an inch, the bullet is swingin in the wind.
But you gotta have clearance.

It takes nearly nothing for pressure to expand a neck so little. Maybe 5psi against spring back force.
It would take a lot more to force a bullet through necks. Around 40psi of friction.
We all know with ballistics that small beginnings setup giant results.
So know this:
The day you rely on forcefully pushing a bullet out of it's neck is the last day you shoot that gun.

 

[nealm66]

It will be interesting to see the results on paper. I think the hammers like a good grip so will be a good test. Will be a couple different depths as well so I'll see what the pudding tastes like

 

[ButterBean]

 

[Longtine88]

Lol

 

[Rosebud]

I once heard in a gun shop in the powder primer section two guys talking about how the powder burns in a rifle case. One of them stated with religious conviction that it burned from the edges all the way around the case into the middle before the bullet made its exit from the case. I almost asked how he knew that but just picked up my stuff and moved on. I've often wondered how someone knows what happens inside a rifle case upon ignition. Are there transparent cases you can watch?

 

[nealm66]

I remember when the wsm first came out they talked about consistent powder ignition in the short fat case. I'd say it's a hard sell nowadays.

 

[Mikecr]

The short-fat powder column does burn more efficiently.
It has to be adjusted for in QuickLoad with 'weighting factor' to calibrate.

It's similar to Gibb's front ignition, which is an even more efficient approach.
Both keep more of the powder burn inside the chamber, instead of burning down the bore as a slug that adds to bullet mass, and muzzle pressure (fireball).

Another efficient approach is going underbore with a cal. A 6PPC and 30br are popular examples.
Very efficient -as long as the pressure is extreme. But this is not viable for hunting capacity cartridges.