when to inside neck ream?

Apollo

Apollo

Jason Stanley
I am making new brass for a 30BR. I want to inside neck ream to achieve more consistent bullet seating force. At what stage do I do this? Reason for asking - if I do it after expanding and before my first initial outside turning - will that mess up my turning mandrel size? I have a Sinclair expander mandrel that fits my Sinclair turner.
I am thinking that I will expand the necks from 6-30 cal - do the inside reaming - then resize down - then use my expander mandrel to open it back up for the right size for my outside turning.
Just asking before I sacrfice 10 cases figuring it out. Thanks in advance.

Stanley
 
This is one option. If you feel a need to ream as I once did, do it before expanding. Then I would fireform the brass without a bullet. You will only have to expand slightly and then turn. I don't seem to get a donut that way.
Butch
 
I think you may be trying to do something that isn't going to benefit you on the target. If you expand and turn the necks to a consistent thickness, when you fireform your cases 50000-65000 ft/lbs of energy has a way or smoothing out the inside of the necks. :) Your seating will be consistent enough until they become workhardened which will be 20 or more firings (just a guess). Some people anneal their brass at that point and others just start with new brass again. Neck turning will do everything you desire without the need for reaming. That's my take on it anyway. Randy J.
 
Thanks. Al Nyhus and Steve Grosvenor told me to do a simple test last year at Webster City - I had marked my cases at which ones seated "easily" and which ones seated "harder". On paper - I couldn't tell the difference. They both smiled and said "See?" Still bugged me though that things weren't the same. Guess that is one of those mental hurdles that I will just have to cross. I won't inside neck ream. Thanks. Have a good one.

Stanley
 
Hard to believe, but you inside neck ream when the bullet does not fit inside the case neck. Outside neck reaming in that case will not do anything for you. If you outside neck turn the case neck will expand and not fit the bullet vary well when you neck size.
 
???????

Big Al said:
Hard to believe, but you inside neck ream when the bullet does not fit inside the case neck. Outside neck reaming in that case will not do anything for you. If you outside neck turn the case neck will expand and not fit the bullet vary well when you neck size.
Click to expand...

The case you state above is easily solved by a bushing die. One simply chooses the proper bushing diameter to achieve the proper size neck to provide the right neck tension. Of course I'm assuming since the thread starter states the 30BR is his caliber, he is going to use "Benchrest" reloading techniques. Sooo...in that case I see no need for inside neck reaming.

virg
 
When I make 30 BR brass I found that there was acertain amount of spring back at the neck and shoulder junction restricting
the outside turning pilot. I solved this problem with a K&M end cutting carbide pilot.

I chucked the pilot in my drill press and ran the pilot into all the necks, no more problem
getting the pilot stuck or running hot.

The extra tension comes from part of the thicker shoulder becoming part of the neck during expansion from 6mm to 30.

If there is any later brass flow this pilot will take care of that too besides it cleans the inside of the necks.
 
Zermel,

If I am understanding your post - you do this after you turn the outside? As of now, I think I am going to leave the inside of the necks alone - however, I might purchase the tool you wrote about just in case I need it later.

Thanks

Stanley
 
Jason: I've been inside cutting all my 30BR case necks before outside turning for the past three seasons. I can't say that it's improved the accuracy, but the outside neck turning process goes a lot smoother. Plus, you know the outside of the neck is parallel with the inside of the neck. The bullets seat smoother and you don't get the occasional tight/loose feeling when seating. -Al
 
Apollo.
I do this after expanding to 30 and then cut cases to length and then outside neck turn.
 
Apollo said:
I am making new brass for a 30BR. I want to inside neck ream to achieve more consistent bullet seating force. At what stage do I do this? Reason for asking - if I do it after expanding and before my first initial outside turning - will that mess up my turning mandrel size? I have a Sinclair expander mandrel that fits my Sinclair turner.
I am thinking that I will expand the necks from 6-30 cal - do the inside reaming - then resize down - then use my expander mandrel to open it back up for the right size for my outside turning.
Just asking before I sacrifice 10 cases figuring it out. Thanks in advance.

Stanley
Click to expand...

Stanley,

please note that this post isn't meant to reflect on any prior posts...... I'm answering you with my opinion, not arguing with anyone else.


Bear with me. Some of my explanation will be obvious to you, it's aimed at those reading this who've not actually seen the effects described.



Picture your brass case, if you were to section it you would see that the shoulder brass is markedly thicker than the neck brass. It's made this way.

NOW, no matter how you do it, when you expand 6BR up to 30BR you fold some thick 'shoulder brass' into the neck. So now your neck has a step in it. This step will be inside or outside..... it wants to be inside since't that's the way it was made. This step will act differently than an un-stepped neck.

-If you expand up on a mandrel the mandrel tries to iron the inside smooth (the mandrel or expander ball is the ironing surface, inside the neck) so the thickness tries to show up on the outside of the neck, in this case you turn it off the outside. This method forces the extra brass to the outside which results in a 'fold' or wrinkle in the neck brass.

-if you blow the cases out in a chamber by fireforming them empty then the OUTSIDE stays flat (because the neck of chamber is the ironing surface) and the inside shows the step, no wrinkle. The step must be reamed for removal.

It is my considered opinion that the best method is to blow the case necks out using shotgun powder (this leaves the step on the inside), ream the inside using a 5-flute reamer (this resurfaces everything while removing the excess brass), polish a little and then turn the outsides to thickness. This seems efficient use of both reaming and turning and keeps the neck from forming the unsightly ring where the grain structure of the brass tries to accommodate the transition from donut to thinner neck.

No amount if firing will ever iron out a donut.

Using the method above you can achieve perfectly consistent tension for 'unlimited' firings using .002 interference or less.

As far as turning mandrel size..... I have my reamers purpose made to match my mandrels size so that I can ream and then turn. Wilson makes reamers in increments usable by me so I measure my mandrel and order accordingly. I also have a handful of straight-fluted machinist reamers in .001 increments around .243.

In all of this one must consider that blasted step, and that thicker brass will expand less and spring back more than thinner brass when mandreled or worked in any way except cutting. How you gonna' get a nice mandrel fit while fighting the step??? IMO by removing the step under neutral tension.

I hope this helps or is even relevant to your situation.

al
 
alinwa said:
Stanley,

NOW, no matter how you do it, when you expand 6BR up to 30BR you fold some thick 'shoulder brass' into the neck. So now your neck has a step in it. This step will be inside or outside..... it wants to be inside since't that's the way it was made. This step will act differently than an un-stepped neck.

-If you expand up on a mandrel the mandrel tries to iron the inside smooth (the mandrel or expander ball is the ironing surface, inside the neck) so the thickness tries to show up on the outside of the neck, in this case you turn it off the outside. This method forces the extra brass to the outside which results in a 'fold' or wrinkle in the neck brass.
Click to expand...

'Mornin', alinwa. :)

On 30BR cases made by expanding over a mandrel, there will still be a significant amount of 'lump' inside the case neck...as well as outside.

Using pin guages, you can measure this pretty easily. Actually, it's not so much a 'lump' as it is a gradual change in the neck i.d. as you get to the bottom of the neck...a funnel shape, if you will. In other words, it's not a matter of the excess material being either inside the neck or outside the neck. It's in both places.

My approach is:
-Neck up over the Redding tapered 6-to-30 mandrel
-Turn the outside 'lump' off
-Using a shellholder with .020 faced off it (to shove the shoulder back .020-.025), I size the case with a f.l. bushing die and a bushing .002 under the unturned neck o.d. This straightens the case neck relative to the axis of the body.
-Cut the inside necks using the Wilson setup and a .3060, .3070 or .3080 cutter. Mostly I use the .3070 cutter, but these later lots of Lapua 6BR brass are all over the place as far as how the necks react to being expanded. I've had to use both the .3060 and the .3080 on this later stuff.
-With a mandrel .001 under the neck i.d. turn the o.d. of the neck. Turn all the way to the 'new' neck/shoulder junction that's .020-.025 shorter via the faced off shell holder.
-Deburr the flash holes and trim to length
-Do nothing to the primer pockets for the first firing
-Anneal
-Clean the be-jeezus out of 'em in acetone, using a .45 cal. nylon brush on a handle to get inside.
-Full length size with a bushing .004 under what the neck measures over the pressure ring.
-Set the bullet .025-.030 longer than 'just touching'
-Use a mid range load of H4198 appropriate for the bullet weight
-Use a bit of light oil (Kroil, etc.) on the case body when you fire 'em.

Done this way, the .020-.025 setback shoulder will blow foward, fit the chamber perfectly and give a nice 'blend' around the neck/shoulder junction.

You can also not set the shoulder back and get great cases. Not everyone is comfortable doing this shoulder setback setup.

After all this 'blah, blah, blah' that I do to make 30BR cases, I have to say that a lot of it probably isn't needed. The way the 30BR's are setup (zero to maybe .035-ish freebore) with the .925 and 1.00 jackets, the base of the bullet ends up no more than halfway down the neck length anyway...even with the not-so-sexy-but shoot-like-the-Hammers of Hell 7 ogive bullets. :D With my 8 ogive 1.00 bullets and .030 freebore, the base is in the top third of the neck length...perfect fit for a case full of H4198 with just a wee bit of compression to settle the ES/SD numbers down a skosh. ;)

Using great brass to start with and a simple neck up/turn/shoot approach has accounted for many, many winning 30BR's.

Jeez...it took me two cups of Silhouwesi to type all this. :eek:

Good shootin'. :) -Al(notinwa) :)
 
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I think it just might be the other way around, Steve. Your '.30 RedRocker' chamber neatly sidesteps all these issues and gives a healthy velocity boost...less any maladies.


From The Minds of Al N and Stan Ware, a great cartridge to be sure.
 
Thanks to everyone for all the great advice. I will print this off - think it over - and make my procedure. In the end - all I want is a perfect case :) Is that so hard?:eek:

Thanks again. See some of you soon at the Beresford 1 liner:D
Stanley
 
Al Nyhus said:
'Mornin', alinwa. :)

On 30BR cases made by expanding over a mandrel, there will still be a significant amount of 'lump' inside the case neck...as well as outside.

Using pin guages, you can measure this pretty easily. Actually, it's not so much a 'lump' as it is a gradual change in the neck i.d. as you get to the bottom of the neck...a funnel shape, if you will. In other words, it's not a matter of the excess material being either inside the neck or outside the neck. It's in both places.

My approach is:
-Neck up over the Redding tapered 6-to-30 mandrel
-Turn the outside 'lump' off
-Using a shellholder with .020 faced off it (to shove the shoulder back .020-.025), I size the case with a f.l. bushing die and a bushing .002 under the unturned neck o.d. This straightens the case neck relative to the axis of the body.
-Cut the inside necks using the Wilson setup and a .3060, .3070 or .3080 cutter. Mostly I use the .3070 cutter, but these later lots of Lapua 6BR brass are all over the place as far as how the necks react to being expanded. I've had to use both the .3060 and the .3080 on this later stuff.
-With a mandrel .001 under the neck i.d. turn the o.d. of the neck. Turn all the way to the 'new' neck/shoulder junction that's .020-.025 shorter via the faced off shell holder.
-Deburr the flash holes and trim to length
-Do nothing to the primer pockets for the first firing
-Anneal
-Clean the be-jeezus out of 'em in acetone, using a .45 cal. nylon brush on a handle to get inside.
-Full length size with a bushing .004 under what the neck measures over the pressure ring.
-Set the bullet .025-.030 longer than 'just touching'
-Use a mid range load of H4198 appropriate for the bullet weight
-Use a bit of light oil (Kroil, etc.) on the case body when you fire 'em.

Done this way, the .020-.025 setback shoulder will blow foward, fit the chamber perfectly and give a nice 'blend' around the neck/shoulder junction.

You can also not set the shoulder back and get great cases. Not everyone is comfortable doing this shoulder setback setup.

After all this 'blah, blah, blah' that I do to make 30BR cases, I have to say that a lot of it probably isn't needed. The way the 30BR's are setup (zero to maybe .035-ish freebore) with the .925 and 1.00 jackets, the base of the bullet ends up no more than halfway down the neck length anyway...even with the not-so-sexy-but shoot-like-the-Hammers of Hell 7 ogive bullets. :D With my 8 ogive 1.00 bullets and .030 freebore, the base is in the top third of the neck length...perfect fit for a case full of H4198 with just a wee bit of compression to settle the ES/SD numbers down a skosh. ;)

Using great brass to start with and a simple neck up/turn/shoot approach has accounted for many, many winning 30BR's.

Jeez...it took me two cups of Silhouwesi to type all this. :eek:

Good shootin'. :) -Al(notinwa) :)
Click to expand...

ABsolutely true :)

You'll notice upon careful pe'rusal that my words are "tries to" push the thickness to the outside........;)

Nice writeup, spot on me' frien'!!!

al-notnyhus
 
alinwa said:
ABsolutely true :)
You'll notice upon careful pe'rusal that my words are "tries to" push the thickness to the outside........;)
al-notnyhus
Click to expand...

alinwa, I knew what you were getting at. :) You opened the door for a bit more discussion on this. Thanks!

I've made 30BR cases by the 'no bullet blow out' method and that method also works well. I put a good deal of importance on the neck i.d.'s being perfectly round before outside turning the necks. Others don't. Kind of a "Tastes great!"--"Less filling!" arguement, for those that remember that beer commercial.

Good shootin'. :) -Al
 
Something I have noticed

among the 30 BR cases I have made over the years there are some that are thinner the last third of their length near the shoulder. I have noticed this when loading longer bullets. What causes this condition?

I have a Wilson .308 reamer and a K&M. I think, for the most part, the Wilson .308 is too big and a .306 mightbe a better choice. The K&M seems only good for removing Doughnuts as far as I can see.
 
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