Neck Turning vs Neck Reaming

[AlNyhus]

There are definite benefits to cutting the inside of necks before outside turning.

The trick is cutting the inside of the neck so it's parallel with the long axis of the case body. None of the commonly available tools will do this, however.

 

[AlNyhus]

I reamed about a hundred 220 Swift cases that shoot fair. And after test firing the reamed cases, I threw them all away. I wouldn’t advise reaming case necks.

Inside cutting the case necks on fired cases will guarantee poor results.

 

[WayneShaw]

Inside cutting the case necks on fired cases will guarantee poor results.

How so Al? To me, a fired case has been formed in the chamber which makes it very straight, as apposed to an unfired case that many times shows wobbling when turning the neck.

When I did it, they turned out great, but I was only cutting out the donut.

 

[C.E.Smith043]

There are definite benefits to cutting the inside of necks before outside turning.

The trick is cutting the inside of the neck so it's parallel with the long axis of the case body. None of the commonly available tools will do this, however.

i wondered that. I thought inside neck turning would be more common if there was a good tool for it.

 

[Straightshooter1]

This is how Virgil King said he did it:

"The necks of the fire-formed cases were next inside bored. This was accomplished on a precision lathe, with the necks supported in a die during the operation."

This is from page 6 of an old article. . . well worth a read for precision shooters:

http://2poqx8tjzgi65olp24je4x4n-wpe...-shooting-magazine-special-edition-1-1993.pdf

 

[AlNyhus]

How so Al? To me, a fired case has been formed in the chamber which makes it very straight, as apposed to an unfired case that many times shows wobbling when turning the neck.

When I did it, they turned out great, but I was only cutting out the donut.

Hi Wayne. For donuts, there's no problem. The issue comes when you're cutting the entire length of the inside case neck. On a fired case, the inside ends up not being parallel to the outside.

Hope all is well with you. -Al

 

[Ccrider]

I have wondered about this. Any benefit to teaming out the doughnut? Some brass will not have them while others do. Will this affect accuracy?

 

[DJSBRS]

Darrel,
To what you are suggesting, I recently turned the necks of some new Peterson 284 W brass and to make a long story short fired it with no issues testing loads. However, upon reloading and firing on the second go around the bolt was noticeably more difficult to lift at the top.(Panda F Class Action) upon remeasuring the neck wall it had uneven high and low spots and some brass flow into the neck junction.
Using Joes suggested method by accident I reuniformed the piece of once fired brass removing a fair amount of clean up off the neck and shoulder junction. This would concur with your observation. My dreaded fear is not knowing if the brass (now uniformed twice) will need additional uniformity on each subsequent firing. Ha!

It is my experience is the brass will continue to flow to the neck shoulder junction upon firing. 40º shoulders not as much brass flow. Thus, you will have to watch for build up at that junction. It is more concerning if you are utilizing tight neck cartridges. That dreaded bolt click can be there as well.

So, I would check them every time I reload.

DJ

 

[WayneShaw]

Hi Wayne. For donuts, there's no problem. The issue comes when you're cutting the entire length of the inside case neck. On a fired case, the inside ends up not being parallel to the outside.

Hope all is well with you. -Al

Cutting the whole thing, I agree 100%.

All is good Al. Retired and loving it.

 

[BenPerfected]

Hi Wayne. For donuts, there's no problem. The issue comes when you're cutting the entire length of the inside case neck. On a fired case, the inside ends up not being parallel to the outside.

Hope all is well with you. -Al

I initially tried neck reaming but ruined a lot of brass before I gave up.