I have never turnrd the outside of the neck on any reload and they have preformed well. Was wondering when it is necessary to turn the neck. I made some 7.7 cases from 30/06 and one of the case necks cracked. Could it have been from thicker metal at the neck?

after several resizings on a case they get worked hardened and the will crack or split.
Neck turning will not correct that problem but anneling will.
Only reason to turn necks would be to fit a tight neck chamberusually custom chamber or to clean up about 60to70% for streighter reloads.

I'D TURN THEM ANYWAY. HIVEL IS CORRECT, BUT YOU NOW HAVE THICK NECKS. RUN THEM THRU AN EXPANDER AND TURN EM DOWN TO NO MORE THAN 0.014. IF YOU USE A MANDREL TYPE TURNER, AND USE A GOOD SEATER, YOU WILL ACHIEVE BETTER CONCENTRICITY.

quote:

Originally posted by Blob1:
I have never turnrd the outside of the neck on any reload and they have preformed well. Was wondering when it is necessary to turn the neck. I made some 7.7 cases from 30/06 and one of the case necks cracked. Could it have been from thicker metal at the neck?

Hivel is dead on here...good answer

Outside neck turning will not correct runout. All it will do is even-up the neck wall thickness.

What does inside reaming of the neck achieve? Someone on another forum posted he had a significant improvement in accuracy by reaming necks. I thought this was only neccessary when forming brass and necking down to a smaller size. Does it produce similar results to outside neck turning?

Imagine this:

You take a fresh case and FL size it. It comes out of your die with .001 runout at the neck. You get all excited about your match-grade possibility.

You then expand the case nect to .001" under bullet diameter to get that nice snug, but easy to seat pressure on the bullet. Just for the hell of it, you spin it on the concentricity gauge and you see that your runout is no longer .001" at the neck, but .0015". Still not bad, you think.

You seat your bullet using benchrest grade equipment, spin it on the gauge and you freak because the runout is .007"! WTF?

While the outside appears concentric, the inside is not. An inside reamer die allows the cutter to go straight down the neck The cutter does not follow the hole, the hole follows the cutter.

The result is that the bullet goes straight down and runout is minimized. What used to be as much as .007" at the ogjive becomes no more than .003".

Ralph said: "While the outside appears concentric, the inside is not. An inside reamer die allows the cutter to go straight down the neck The cutter does not follow the hole, the hole follows the cutter."

Not sure if that happens, since the case is normally held in a collet or shellholder. Easy for the case neck to shift, and allow the neck reamer to follow the path of least resistance, i.e., down the middle of the neck, leaving the same neck variances.
Outside turning, by using a pilot or mandrel, allows removal of the "high spots/thick areas", as the case neck is held in a consistant axis during cutting.
It does seem the only time neck reaming is necessary is to remove the "doughnut" often found near the base of the neck, following case reforming. It occurs in an area not accessible to outside turning.

I was talking about an inside reamer die.

The die is a FL sizer die with a reamer hole instead of a decapping assembly. The case body and neck are sized down in the die and while the case and neck walls are fully supported by the die, the reamer is run through the neck. The result is a perfectly straight hole with perfectly even neck walls.

Total runout, in my experience was reduced by 60%.

quote:

Originally posted by Ralph Hyrlik:
I was talking about an inside reamer die.

The die is a FL sizer die with a reamer hole instead of a decapping assembly. The case body and neck are sized down in the die and while the case and neck walls are fully supported by the die, the reamer is run through the neck. The result is a perfectly straight hole with perfectly even neck walls.

Total runout, in my experience was reduced by 60%.

Never heard of that one! Who makes `em? Sounds interesting.

RCBS

FWIW and what works for me.

I reload for some oddball calibers: 7X64 for example (oddball in the sense that the brass is not that common here in South Africa PMP make the brass but it is very expensive)

I take for example a 30-06 case and neck it down to 7X64 and fireform it with a lead cast bullet. Gives me a nice thickish neck (thicker than 7X64 spec)

Then I put it in a Forster Case trimmer and use the 284 reamer as a mandrel WITH the neck turner to create a concentric neck.

Gave this hint to a pal who uses a 30-06 cases to make 25-06 and he gets really good results. Similarly in the old days when 22-250 brass was unheard of I used 243 brass. It was a bitch of a process but it worked

Cheers

pete

The Forster neck turning attachment follows the hole, and if the hole is crooked, then so will the neck after turning.

I believe that Norma and Lapua ream their necks. I base this on the fact that the shoulder thickness of their brass is more than twice that of the neck walls.

[QUOTE]Originally posted by Ralph Hyrlik:
The Forster neck turning attachment follows the hole, and if the hole is crooked, then so will the neck after turning."

If the die is that bad, it won't matter how or if the neck is reamed or turned...
and if the chamber is that bad, how can "fixing" the brass help much?
The case neck ("hole") location is determined by the die, and whether it's off-center or not (hopefully not much, are the dies are lousy), the neck turner pilot allows for the neck wall thickness to be made uniform.
Usually the test of seeing if a bullet will slip into a fired case will tell if it may be needed.

As to the "neck reamer die"...did not see it on RCBS's site, plus how is the reamer utilized in such a setup?

If you section a case, you'll find that the walls are uneven in thockness. As you examine the circumfrence, you'll find alternating areas of thick and thin brass.

Typically, one side of the case is thinner than the other, however there may be thin spots all over.

The neck is thinner than the base, but still carries over the defect. If you FL size the case and have no runout whatsoever, that doesn't mean the inside of the neck is perfect. All it means is that the outside is perfect.

The inside of the neck is still thinner on one side. This means that in a perfect scenario, if the neck is uneven by .002" then the runout should be .002". Right?

Wrong!

Not only is the hole .002" off center, it may curve into the case body or cant away from the centerline. We have no way of examining the inside of the neck.

If you seat a bullet into a hole that curves or cants away from the centerline, then the bullet will follow that curve or direction awazy from the bore.

I have rounds that read .001" runout on the neck and .007" runout on the ogjive. The neck thickness is off by .001"-.002", but where does the extra runout come from.

Well, it must be the internal profile of the hole.

The reamer die looks like a regular FL sizer die, but instead of a decapping assembly it has a hole for a 4" long reamer. My 22-250 reamer die takes a .2225" reamer. The case is sized down, the reamer cuts a perfectly concentric straight hole, and the loaded round has mimimal runout.

Whatever the hole used to look like, is no more.

This is a special order item.

Is this what you're talking about

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=611932

if so, I can't find a regular caliber like 270 or 30-06 anywhere on 24 pages


C'mon, RH, clue us in on how you get one and how much they cost!

Without guns we are subjects, with guns we are citizens

Yes, that is it.

I bought mine from Huntingtons.com for $80. The reamer was $80, so the total was $160. It took 20 days to make it.

They don't have them listed.

You have to call them or RCBS to have them made.

FWIW I completely agree with Ralph. Another less satisfactory alternative, and not quite as expensive as the reamer dies from RCBS, is to use the Wilson case trimmer with their inside neck reamers. They will make them as a custom item for any internal diameter you require. The cases are held in a "case holder", a die of sorts with the neck unsupported, and while you have a slight bit of slop, even as you have for the RCBS type, you can successfully ream the insides "pretty concentric". Not perfect, but it is a way to remove donuts from the base of necks and remove some of the high spots from the inside.

O

Of course it is a regular practise to use 30/06 cases to make 7.7 x 54 cases. And the one that cracked did so on the first shot. None of the others did this. I though maybe the 30/06 case may have been thicker at the neck and needed reaming.