Who is reaming the brass neck ID and why?

bigHUN

bigHUN

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In my case, a new to me Win 308 brass and Sierra 155gn bullet 2155/56 press fit is in my focus.
So far I seized the neck with Wilson 0.332 bushing, fitting the bullet is tight with 0.003" overlap.
More so because inside wall the brass neck is - eroded not entirely a full diameter? if I can explain with my words...
I will load and shot this amo for now as is, but next time preparation I may resize the neck "bigger" let say 0.334",
ream it (I have a Wilson reamer),
anneal and resize again with 0.332?
Not sure about this yet, only speculating. (Winter is just up to hit the range so plenty of time on my plate.)
Why you guys reaming the brass and what sequence you do it?
 
I have neck reamed twice in the past during brass re-purposing. My most recent project was making 300 Savage from a variety of donor brass. I tried 308 Win, 30-06, 25-06 and 270 Win donor brass for suitability and all worked after reaming.
 
Neck reaming or neck turning can result in very uniform neck thickness. Often it is done in conjunction with a specially reamed chamber, to produce minimal clearance. "Fitted neck".
If brass is high quality and uniform and the chamber fit is good, don't know if there is any point.
Like Boolitcaster, I have reamed brass as part of case forming routine, to eliminate thick necks.
 
If you take a fired case and put down over an unfired round and it is more than just a fairly easy slip fit then there is not enough clearance for the case to expand when fired to release the bullet without raising pressures. Then a neck turning would be in order . The number of times I have seen fired cases that had to be forced over the unfired rounds to check for clearance is enough to make me neck turn .
 
Valid points, very educational.
In my case - never say never, but - I will most likely re use fired brass, not really inclined to mix with new shells.
What I am after is, to do a good home work and minimize the friction inconsistency when pushing the bullet into the case.
 
A light cut would certainly smooth the neck walls, probably increase uniformity.
A reamer used in conjunction with a reamer die will result in neck concentricity. If it is a reaming cutter used with a case trimming rig, the neck will be smoothed internally, but I don't know if concentricity would be enhanced.
 
I just finished loading a batch of 50 for testing @ 300 M. Powder weight incremental 0.2 with seating depth of 0.030"
Replaced the handle on my press to a thinner but longer bar, and I could feel some of the necks was harder to push the bullet in.
These brass were turned from new blanks by a friend of mine, got these earlier these year.
I will shoot the entire box of these 100, and ones the chamber formed the neck OD I will start the preparation fresh from zero.
 
I assume if we neck OD turn that is just a half job done. Same with neck ID reaming..
Ones the brass is shot just measure the wall thickness.

Btw...
I have not seen it anyhere talking about - What is a safe minimum neck wall thickness on Lapua Win 308 ?
 
On this matter of neck tension, and reloading in general, I think its fair to say you've "gotten ahead of your skiis". I dont neck turn, but I do anneal, and I do feel (literally) that I'm getting consistent neck tension. If I was considering neck turning, I would base the decision on my sizing technique - either mandrel based or bushing based. Mandrel based sizing would benefit from OD neck turning, bushing based would benefit from ID neck turning. Doing both ID and OD turning, while appealing conceptually, could very easily turn into a can of worms. Additionally, the turning operation increases the clearance between the chamber wall and the case OD at the neck. Ideally, this clearance should be kept to a practical minimum. (Match chambers have a minimal neck diameter to benefit bullet concentricity in the chamber.)
I use a LEE collet die (mandrel based). I prefer this over a bushing based die as the collet die can accommodate different brass types and wall thicknesses without having to buy a bunch of bushings (PIA). I strongly believe in annealing as it resets the yield strength to minimum value (ductile), makes the sizing operation easier, and is less prone to springback. This is a major contributor to consistency.
BTW - Did you chamfer the inside of your case mouths before seating the bullet??
 
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I turn OD on my 30BR and my 6xc-250-3000 because they both have tight neck chambers. IF I had the bucks I would consider the AUTODOD Case Neck Turner but is a lot of $ for what you might gain. It turns both inside and outside of the neck in one operation. I turn my necks to~ 9-10 thou some bench guys go as low as 5 or 6 but they are a different breed. If you do decide to turn your necks with a hand held tool do a bunch of garbage brass till you get the feel for the operation.
 
First you need to have a match chamber which is really tight on neck clearance, and ideally you have a iDod or AutoDod, which can the both ID and OD turn perfectly. Turning the neck using a drill like tool with a reamer is not something I would recommend, just the OD turning would be enough for majority of the people and you probably won't notice any difference.
 
Try the 21st Century neck expanding mandrel set after the bushing die.

Gives very consistent neck tension.

Might achieve better results with a lot less work.
 
Unless you have a "custom chamber" turning necks is "futile" but if it makes you feel good, go for it.

If you want to experiment just to verify it for yourself, by all means do it. I did and it didn't take very long to figure out that it's just a waste of time in most factory chambers.

The idea of getting "custom" chambers cut is to be able to keep expansion to a minimum when the cartridge is being fired.

If you're trying to "cure" an accuracy issue with your firearm by turning the necks, you've got a different problem.

Sloppy or cut to max spec chambers can be a real issue, which does have a negative effect on accuracy. Full length resizing and neck turning only make it worse.

I have a good friend who is an accuracy fanatic. He has purpose built rifles, with custom chambers which require the necks to be turned and custom dies with neck inserts for those cases.

His process for neck turning is not an option for a lot of shooters, because he uses a custom mandrel in sized necks to expand the brass, then turn off as much as required and attain consistent neck wall thickness.

I used to think he did this to custom fit the cartridge cases to the chambers of each rifle. Not so. He did it because he didn't like that some cases have thicker necks than others and he wanted them to be consistent.

He used to be fanatical about turning necks, now, after thirty years, but only with his hunting rifles, with factory cut chambers, he no longer turns necks.

He did some very extensive testing with his new Savage 6.5 PRC chambered rifle and came to the conclusion it was not worth the effort, maybe even had a negative effect on accuracy and case life.

OP, your call. Many folks swear by it and I remember when it became the "rage" among shooters, because BR shooters were doing it, so it had to be a good thing.

Most didn't do enough due diligence to find out "why" the BR shooters were doing this.
 
liberty said:
Try the 21st Century neck expanding mandrel set after the bushing die.

Gives very consistent neck tension.

Might achieve better results with a lot less work.
Click to expand...
Great tool if you don't have a tight necked chamber. I throw away most of the factory die expander buttons and only use mandrels. Much easier to get consistent necks plus your not sucking the expander back out of the case and possibly introducing errors. Some bushing dies will not do the entire neck to the shoulder so be careful. Many ways to skin a cat but some ways work better then others.
 
Neck reaming tools are an invaluable tool in my opinion when you're necking down cases or cleaning out multiple Fired cases that have a tendency to thicken the neck walls from brass flow. IMO the only accurate way to ream a neck is by supporting the outside of the neck while reaming the interior and the only company that has made these dies is RCBS (AFAIK), they are called Neck Ream Dies and are caliber specific, you get a die and the correct reamer for reaming the inside of the neck, always a perfect result, they are fantastic.
BB
 
bigbull said:
bigHUN, the Wilson reamer does not do what the RCBS reamer does, they work in different ways.
Click to expand...
I don't know how the RCBS works and not planning to mix my existing Wilson tools with other Brands.

Just speculating = estimating only how can I work with what I already have - the Wilson case trimmer kit with reamer.

I am talking about a Lapua 308 brass, and what I currently did is a sizing the (annealed) brass neck OD to 332 and press the bullet.
And this how I discovered that the neck inside wall is a bit rough from eroding after the shots... most likely different consistency as well.

Planning to change my process a bit I just need new bushing sizes:
- size the neck OD larger to 335 or 336 - I will need to measure the actual brass wall thickness, calculating only is a hit or miss.
- ream the ID with Wilson reamer (the reamer OD is bullet OD + 0.002")
- re size the OD with 332 (or whichever gives me 0.002" press fit)
- press the bullet into a now smooth neck ID
 
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