inside or outside neck ream ?

[remvls]

I want to know if :
Inside neck ream,with forster tool), just after firing and before sizing, can replace the outside neck turn in order to have a good concentricity ?

Or maybe we must the two,inside before resizing and outside after resizing)?

Or maybe i ùust only one outside nech turn after sizing ?

I think with a firing brass,not resing for the moment), the outside neck diameter of the brass is the same of the inside barrel neck diameter, and if i turn only the inside of the neck, i think it make a good concentricity, what do you think ?

 

[357Mag]

Rem -

Can you tell us bit more info ?

What case/cartridge are you shooting ?

Are you forming your OWN brass ?,case forming,or wildcatting ?)

If you are wildcatting by necking-down the basic brass, you may very well need to do both processes.

If only reloading " factory " brass, a SAAMI-spced case ),
you should not have to inside-neck ream.

As for outside neck turn, answers will vary.
Guys who shoot zillions of rounds each year, probably wish to avoid neck-turning. They long for a " no-turn " neck.

My personal experience w/ factory brass was that one could always do a " skim " outside neck turn, to remove the "orange peel " surface of the outer necks. It was not uncommon for these skim trims to remove a miniscule amount of brass from one side of a case neck; but not all-the-way around.
That condition showed neck " out-of-round ".

Motorized neck turning machines have speeded the whole neck turn process up, with no loss in trimming accuracy.
That lies more w/ the trimmer device itself, and of course
technique'.

Best of luck in uour endeavors.

Regards,
357Mag

 

[remvls]

Hi 357 mag,

It's for 243 winchester and reloading factory brass : Lapua or Norma. I want to want accurate handload...

I have a forster case trimmer, with inside reamer and outside reamer accesories.

I understand from you, that inside ream is not necessary.

and for outside ream, answers will vary...

what's your advise ?

 

[janderson0]

Sounds like your shooting a factory gun. What clearance do you have now for neck-chamber clearance. Measuring a loaded round and fired round should get you an answer to within .001. While any turning should improve concentricity you are at the same time increasing neck-chamber clearance for a sloppy fit.

If you are starting with Lapua brass, its a safe bet your as good as gets already.

Jim

 

[Preacher]

The inside reaming will follow the hole, and if it's off it will still be off after reaming.
Neck turning will leave the sides the same and is the best way to obtain neck concentricity .........

 

[Bob3700]

Outside neck turning is the inexpensive way to clean up necks. Benchresters have been doing it that way for years. The necks are straight but not necessarily in line with the case itself.

If you want absolutely true necks, in-line, inside neck reaming is the way to go. It is more expensive because you need a die that holds the case and neck in alignment and then runs the reamer thru the die from the top.

Huntington made them years ago and Merril Martin,wrote for PS years ago) proved their superiority to outside neck turning.

Because the dies and reamer were custom made, they were expensive. But it is THE way to ensure straight and true necks.

Probably too much effort and expense for a factory chamber.

You might try necking down 308 brass and then outside neck turning to get a more custom fit of brass to your chamber neck.

Bob

 

[mikecr]

I agree with Preacher.
You're not trying to 'straighten' brass, or 'create concentricity' with turning. You're just setting neck thickness to a uniform & correct value.
With this, your chamber, dies and case springback, should allow for loading with low runout.

It won't help if a reamer leaves the hole straight, but doesn't result in low thickness variance. The first time you fire and then size, you'll have a mess no better than you began with.

Look, turning works. Just measure your new brass neck thickness, set the cutter to produce desired thickness, and make it so.
When you seat the bullets and measure the necks, they will measure exactly what you desired and set.
After fireforming you'll measure almost zero runout.
After sizing you'll measure some.
After seating you'll measure a little more.

But because you turned, you'll know the runout isn't your brass.

 

[remvls]

Hi,

Can you confirm me this method for Outside ream :

With Brass new :
1) Resize.
2) Turn outside.

With already fired brass :
1) Resize
2) Turn outside.