taper reamer inside necks, cb accuracy

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  • Last Post 20 May 2018
Ken Campbell Iowa posted this 16 May 2018

while prepping a cigar box of mixed, mongrel  30-06 brass for groundhog targets, it came upon me that if just ID taper reamed the necks it would save me from deburring, flaring neck mouths  and probably excess working of necks from the belling/sizing at each reloading ....

also i remembered that in the few ( 3 or 4, in 22 and 7 mm  ) instances i had tried it years ago while developing serious loads, it seem to give better groups over straight neck loads  ...

maybe it allows the bullet to pivot from deeper in the neck ... thus more self-alignment ?? ....  kinda like our bench gurus who seat just by the gas check ....  and maybe it allows the soft bullet to expand inside the neck before it moves forward and thus gives a better fit in the throat (  since many throats are bigger than a bullet that you can seat into a factory spec neck ) ...

i remember JohnA mentioned this a while back, so maybe next loading i will taper ream the whole box ....  not like it is 284 winny brass, i guess.   any comments welcome.

ken

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John Alexander posted this 20 May 2018

Run, Run!!!, the VTZ Zombie is out of its grave and running amuck among cast bullet shooters. See TFS numbers 223 and 240 for protection.

John

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beltfed posted this 19 May 2018

Guys,

( I think) the guys that are annealing BP ctg cases every reloading are more

concerned at having the same case neck tension on their bullete each time.

For me, I use FF cases with NO neck tension.  Easy to maintain that way.

I just run the cases into a M die to make sure of any possible dings after

tumbling

beltfed/arnie

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frnkeore posted this 19 May 2018

One of the more safe and successful ways to get broken necks out, is to put a stop in the barrel, ahead of the neck, then pour that area of the chamber with lead or Cerosafe and drive it out.

Frank

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Ken Campbell Iowa posted this 19 May 2018

ric... re::  broken case neck stuck in chamber ....how about running in a chamber reamer another 1/2 thou.... cut the brass bushing out ....

ken

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45 2.1 posted this 19 May 2018

Full annealing isn't usually good for fixed ammunition as dead annealed usually produce poor groups. You can draw some of the brass hardness from the neck via a timed dunk in molten lead. Done every once in a while it allows you to keep a medium hard neck without cracks developing.

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Ken Campbell Iowa posted this 19 May 2018

ooops i made a mistake... i corrected in above post now:

american taper pin reamers are 1.1 degrees included ... not 2 degrees  ...  are about 0.022 per inch ....  so in a quarter inch neck just kissing the bottom the neck mouth  would lose about 0.005 diameter .  i have pin reamers for the smaller calibers but not 30 cal.  about $20+ from drills&cutters.

ken

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Tom Acheson posted this 18 May 2018

Not trying to keep beating the annealing dead horse....but...I found this on a BPCR forum site. The opinions there about the merits of annealing are as wide spread as they are here. But quite a few of the posters (over the last 3-4 years) have bought annealing machines.

The problem with annealing is, that even if you understand the metallurgy, it is so hard to do uniformly that it is likely to do more harm than good. AND, if your cases FIT after being formed, you WANT them to stay as hard (strong) as possible. Otherwise you will be getting stretched necks and bent case mouths. This is one of those "what works for you" things. Some anneal every firing. Some like me, once or twice a season, some not at all. As with most everything else, find what works best in your rifle.

 

Tom

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R. Dupraz posted this 18 May 2018

Good ! Back on topic.

After reading your posts Ken, I'm now wondering if that idea would have some additional positive effects if the neck is reamed that far down. Would not the bullet then have some clearance at the mouth of the case to maybe self aligne with the bore instead of being forced into the throat as in conventional seating ? 

I can't go nearly that far with the reamer that I have, with a 10-11 degree taper but might could go 1/3 in that short necked 6mmx223 before destroying the mouth. Some bullet designs that I have been trying in that 6mmx223 now are seated shallow enough so that when chambered, the bore does the aligning perfectly. Why wouldn't it be the same thing only with the bullet being seated deeper in the neck demanded by a short throated bore?  

Think I'll dig some more LC 223's out of my stash and see what happens.

 

R. 

 

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Ken Campbell Iowa posted this 18 May 2018

beltfed::  

yes i am talking about taper reaming at least half way down the inside of the neck .  enough so that there is no contact at the very mouth of the neck.  with standard dies i would think you have to leave a little unreamed section at the lower neck .

cons ( maybe ... with cast everything is a * maybe * ) ...  the thin mouth is weakened for handling .... easy to ream too much and remove some neck .... less bullet grip, not secure for hunting .........  oh, and me personally i have not enough shots to be sure it actually is more accurate ...  and i am sure there are cartridges/rifles where this might not be a good idea ....

thanks everybody for your ideas ..... ken

 

 

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John Alexander posted this 18 May 2018

Tom,

Interesting about the black powder folks being so concerned about the neck sealing. I am always curious when I hear of some extremely labor intensive reloading procedure and annealing between every shot would qualify.

I know nothing about BPCR shooting so this may be a dumb question but what bad thing do they think (or know) will happen if the neck is a little work hardened and doesn't seal quite as quickly besides smoke on the outside of the case neck?  If enough gas escaped to affect the chamber pressure and velocity it would be disastrous to the shooter. Is it just about keeping the action being gunked up?

As a depression baby i always shoot cases until the necks start to crack and have never seen any bad effects of shooting the extreme work hardened necks just before they gave up. Of course I haven't been shooting black powder.

John

 

 

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Tom Acheson posted this 18 May 2018

Resurrecting the annealing thing. Two thoughts.

I shot a round known as the 30 PPC for several match seasons. After a Regional match the fired cases went into a vibratory case cleaner. In the process of poking media out of the flash hole, here was a case with no neck! Examining the media I could not find it. Oh oh…there it was in the throat of the gun. My good friend John Kaufenberg and I tried quite a few stunts to extract that piece of neck material but no luck. So that had to be the very last round shot at the match…talk about strange. It could have been the first round and I would have been out of luck at the match. Those Lapua cases had been fired 24.75 times each until that first failure. They were never annealed. Had they been annealed I might still be shooting that round today. Off comes the barrel and new one was installed.

The black powder cartridge crowd is quite focused on annealing. Not just for case life but to support the theory that the case mouth needs to be flexible enough to expand upon ignition to develop a good gas seal in the chamber as the bullet heads down range. An annealed neck is soft enough to allow the neck to “flex” to meet that need. So maybe the black powder parameters are different than smokeless? Who knows. But you’ll not convince very many of them to quit annealing. Some of them are so committed to annealing that they anneal all cases after each firing.

FWIW

Tom

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beltfed posted this 18 May 2018

To clear this up:

Ken C:

Are you initially in this thread really talking about "long, gradual taper inside neck

Chamfering"?  In order to allow gentle seating of bullets?

beltfed/arnie

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OU812 posted this 18 May 2018

Such as taking a fat Lyman 314299 bullet and swaging it down to fit your new factory 308 rifle. Swaging down the whole bullet (bands and bore ride section) in one easy step.

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John Alexander posted this 18 May 2018

45 2.1,

You are of course right, there are always several ways to skin a cat and interesting discussions are what make the forum worthwhile and fun. I, and I am sure others, would appreciate further discussion on the topics you hint at.  As time allows, please start one of more threads on these topics and how they could contribute to our cast bullet knowledge.  You could start by giving us your experience with the technique which I'm sure would be educational and well attracting lively contributions from others.

Thanks in advance.

John

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45 2.1 posted this 18 May 2018

There are other options also. Whether they work or not depends entirely on the methodology used and choices a person makes........... even with loose tolerance necks and chambers. Oversize bullets, alloy choice, load pressure along with stop ring bullets are all topics that could be discussed here.

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Bud Hyett posted this 18 May 2018

John - Now I understand the thread beter. I am a strong advocate of outside neck turning as I use bushing neck sizing dies. This is from the jacketed bullet days where I reduced the expander button by .001 / .002 to smooth it and to give tighter grip for more uniform ignition. 

The thought of inside taper reaming to ease the bullet entry while seating is deburring in essence. With new brass, we deburr the outside and inside of the neck as a matter of course. Initially using the standard tool, the deburring worked. This tool was replaced for the inside neck by a long taper chamfer tool to deburr plus remove a slight amount of metal for an inside taper. 

Alice and I are experimenting with tighter neck tension now for her Savage. The lighter velocity loads show greater vertical dispersion at 200 yards. The variables are; 1) neck thickness, 2) case neck tension, 3) how many shots since last anneal.  

On a side note, I remember meeting Fred Huntington stopping at Freeland's in Rock Island, Illinois many years ago. Fred stopped  on his return flight from the NRA Annual Meeting and was caught the next day by the airport being totally fogged in. Al Freeland called several serious shooters to meet him including my uncle Verne. (Verne called me and told me to report at his house,)

I sat like a mouse in the corner and listened, I was just then starting reloading. The discussion was case neck tension and accuracy. The subject was between neck-reaming and outside neck turning. This discussion soon turned into a serious debate. There were strong opinions. 

Farm boy from Illinois, living in the magical Pacific Northwest

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Ken Campbell Iowa posted this 17 May 2018

thanks guys for the enlightenment on the inside reaming die. 

i am now brought along to the point that since the od of the neck in the sizer is round, if the neck wall varies, then the inside hole has to be off-center ..... so the reamer has to cut a diameter at least big enough to take a teensy cut on the thinnest neck wall, or you wind up with that egg-shaped hole i was worried about.

so whether you neck turn or inside ream it appears that a lot of pre-planning is required;  co-ordinating chamber neck dimensions, new sizing die/bushing/collet spindle .... and bullet diameter.      but then i just loaded a couple hundred rounds in old conventional dies ... still hearing that squeak from the expander buttons ...   

thanks again ....  ken

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frnkeore posted this 17 May 2018

This is what a RCBS, inside neck reamer looks like.

The reamer shank has about .0003 - .0005 clearance in the reamer body and the case neck is contact with the die.

Frank

 

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John Alexander posted this 17 May 2018

45 2.1,

Thanks for bringing up other options. Of course breech seating doesn't involve sizing the case and the cases should last forever.  The same should be true for custom match rifles for loaded cartridges with a tight necked chamber. These setups require only a few thousandths of sizing - OR NONE if set up tight enough that elastic spring back of the case neck will still grip the next bullet.  Of course the jacketed bullet crowd with this type of chamber push the limits of pressure and life is probably limited by cartridge head expansion of primer pockets. Some of our heavy and UNR and UMP shooters may use similar pressures for their 30BRs and such.  However, with a tight necked chamber and pressures kept to usual CB pressures their cases should last almost forever -- just like breech seating. However I have never asked them. 

What about it all you custom chamber shooters how long does your brass last if you keep the pressures low???????

That said, my interest is in cast bullet performance in factory rifles and am stuck with factory chambers and their required tolerances.  These usually let the case neck expand in the neighborhood of 0.008" from the neck diameter of the loaded cartridge and there isn't much you can do about. (Short of specially manufactured thick neck cases (maybe 22-250 cases made from 30-06 cases to get a thicker neck.)  So sizing is necessary to grip the bullet but using either a collet die or a bushing type neck sizer can make cases last a very long time without annealing at the usual CB pressures.

John

 

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John Alexander posted this 17 May 2018

Bud,

I didn't explain well enough.  What I was describing in my post and in the FS article as well has nothing to do with reaming the neck for uniform thickness.  The taper reamer is used to make the inside end of the neck only slightly larger than the diameter of the bullet base to let the bullet get started smoothly and without shaving lead -- same as the purpose for flaring.

This tapering requires no particular precision and can be done by hand because when seated the bullet doesn't tough the tapered part  of the neck.

John

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