6BR neck expansion die and mandrels
- Thread starter JackWagon
- Start date
Dolomite
Silver $$ Contributor
Try these gauges to see what the ID of the brass is after you do all your resizing. This may help you diagnose the sized necks and determine what mandrels or bushings you want to use. It should help determine if you are getting inconsistent neck tension.
MATCH GRADE - Case Mouth and Neck Tension Gage 6.0 / .243 / 6.5 / .264
Match Case mouth gauge or gage for determining neck tension of 6mm BR, 6.5 Creedmoor, 6mm Creedmoor, 6mm Dasher etc. Match grade.
ballistictools.com
Neck ID means nothing about neck tension.
Again, what you're referring to is interference.
Hardened necks with 3thou interference provides completely different tension than fully annealed necks at 3thou interference.
And partial neck sizing provides different tension than full neck sizing, regardless of interference.
You see what I'm getting at?
Take a moment and think, for yourself, about what grips bullets.
Consider how the hoop tension provided by necks works.
Think about what happens with sizing, and bullet seating, and when you fire a round in your chamber.
Again, what you're referring to is interference.
Hardened necks with 3thou interference provides completely different tension than fully annealed necks at 3thou interference.
And partial neck sizing provides different tension than full neck sizing, regardless of interference.
You see what I'm getting at?
Take a moment and think, for yourself, about what grips bullets.
Consider how the hoop tension provided by necks works.
Think about what happens with sizing, and bullet seating, and when you fire a round in your chamber.
YEP! that is exactly what I do @ time before reloading a case...
SS wet pins {no more than 1.5hrs after 24hr soaking cases in hot solution to cover of Boretec sonic cleaner-10ml, dash of dish soap, airline stirring spoon (very small) full of Lemi Shine.}
Then same into the tumbler... Beautiful and tarnish resistant, primer pocket/flash hole clean, Hornady Case Duo the exterior of case mouth, K&M tapered case mouth reamer inside, AMP annealed, Foster neck size and bump with expander ball. Works for me... {:~)
Just a quick update, I picked up all of my pin gauges came in. Used my upright belt sander with 400grit to taper them with my drill running counter to the sandpaper. Then I used my dremel with the felt wheel and extra fine buffing compound. The Lapua even after annealing has some serious spring back and ended up having to use the .243 pin BUT it seems my seating issues are gone.
On another note, the Peterson brass came in and visually and by weight out of 50 they only have a 3/10 grain variance in weight. By looking at the annealing line it is clear they use some kind of collar or heat shield as each piece of brass has a perfect annealing line.
A quick test with the lapua yesterday showed my flyers are all but gone at 30.2 gr of varget. I just finished loading up both lapua and Peterson and heading back to the range to play with seating depth on the Lapua and charge weight on the Peterson. I se some folks are saying the internal capicity on the Peterson is less so I am starting at 29.6 and working up to 30.2.
A word of warning on using the pin gauges, be VERY careful. If you run to far the case will hit the collet and ding it. Yea, learned that the hard way....lol. I am going to order the die and mandrel set but I am still ahead of the game as the pin gauges were only 3.30 each and was able to order them from a local company suncoast tools which is only 30 minutes south of me.
Sorry for the long winded post but I wanted to make sure to say THANK YOU, you guys are the best.
On another note, the Peterson brass came in and visually and by weight out of 50 they only have a 3/10 grain variance in weight. By looking at the annealing line it is clear they use some kind of collar or heat shield as each piece of brass has a perfect annealing line.
A quick test with the lapua yesterday showed my flyers are all but gone at 30.2 gr of varget. I just finished loading up both lapua and Peterson and heading back to the range to play with seating depth on the Lapua and charge weight on the Peterson. I se some folks are saying the internal capicity on the Peterson is less so I am starting at 29.6 and working up to 30.2.
A word of warning on using the pin gauges, be VERY careful. If you run to far the case will hit the collet and ding it. Yea, learned that the hard way....lol. I am going to order the die and mandrel set but I am still ahead of the game as the pin gauges were only 3.30 each and was able to order them from a local company suncoast tools which is only 30 minutes south of me.
Sorry for the long winded post but I wanted to make sure to say THANK YOU, you guys are the best.
I have to ask ChuckWagon about a couple things...
The first is how you are chamfering the inside case mouth. The cheap neck deburr tools sold for this purpose do not in my mind have an ideal cutting angle and worst yet, they are not sharp enough to do a really nice job of it. I've been using 1/4" shank cone shaped carbide burrs to do the inside and feel it is a game changer for how it improves seating pressure.
If you do this lightly after stainless media tumbling you will not have any problems with dented case mouths.
The next thing is with regard to sizing bushings...
What is your sizing process?
If you are currently not neck turning then any neck wall stock variability will transfer to the inside and influence neck tension variability.
The next variable is case to case hardness variability. This affects spring back.
Here's a trick you can try that will almost certainly sort out the problem... I hope I'm clear enough for you to understand.
This works best with a neck only sizing die. An FL die will not allow you to feel this, but it still occurs.
You need to size and resize the necks in 0.001" increments, not just one pass for all cases. Neck turned brass will reduce the range of bushing sizes you will need.
Start with a neck sizing bushing that is at least one size too large to hold a bullet after sizing. With a normal factory chamber you will notice the case is easy to draw out of the bushing. This is because reducing a neck by 0.012 diameter in a single pass creates a taper to the neck side wall. When you draw the case out of the bushing there will be no resistance and you can feel it. The next step will reduce that neck taper.
Now size the cases again with the next bushing smaller. This time, you will feel the resistance when you retract the ram as the neck side wall is now parallel after sizing.
At this point using a bullet as a go/nogo gage, set aside any case that is tight enough that you cannot push the bullet into the neck by hand. Keep those in one bowl and all lose mouth cases in a separate bowl.
After you run the batch, reduce the neck sizing bushing one more size, and run all the cases from both bowls again.
At this point, the bowl that was already tight with a bullet has at least 0.001" neck tension and the side walls are parallel. These are ready to load.
Repeat this process until all cases have been sized with a bushing that is 0.001 smaller than what it takes to hold a bullet.
If you think about what this does, it sorts cases according to two factors...
1) case to case variations in neck hardness
2) case to case neck wall thickness variation
My guess is that this process will result in significantly more consistent seating pressure.
This was essentially my process for processing brass for F Class before I started running tight neck chambers and neck turning.
The first is how you are chamfering the inside case mouth. The cheap neck deburr tools sold for this purpose do not in my mind have an ideal cutting angle and worst yet, they are not sharp enough to do a really nice job of it. I've been using 1/4" shank cone shaped carbide burrs to do the inside and feel it is a game changer for how it improves seating pressure.
If you do this lightly after stainless media tumbling you will not have any problems with dented case mouths.
The next thing is with regard to sizing bushings...
What is your sizing process?
If you are currently not neck turning then any neck wall stock variability will transfer to the inside and influence neck tension variability.
The next variable is case to case hardness variability. This affects spring back.
Here's a trick you can try that will almost certainly sort out the problem... I hope I'm clear enough for you to understand.
This works best with a neck only sizing die. An FL die will not allow you to feel this, but it still occurs.
You need to size and resize the necks in 0.001" increments, not just one pass for all cases. Neck turned brass will reduce the range of bushing sizes you will need.
Start with a neck sizing bushing that is at least one size too large to hold a bullet after sizing. With a normal factory chamber you will notice the case is easy to draw out of the bushing. This is because reducing a neck by 0.012 diameter in a single pass creates a taper to the neck side wall. When you draw the case out of the bushing there will be no resistance and you can feel it. The next step will reduce that neck taper.
Now size the cases again with the next bushing smaller. This time, you will feel the resistance when you retract the ram as the neck side wall is now parallel after sizing.
At this point using a bullet as a go/nogo gage, set aside any case that is tight enough that you cannot push the bullet into the neck by hand. Keep those in one bowl and all lose mouth cases in a separate bowl.
After you run the batch, reduce the neck sizing bushing one more size, and run all the cases from both bowls again.
At this point, the bowl that was already tight with a bullet has at least 0.001" neck tension and the side walls are parallel. These are ready to load.
Repeat this process until all cases have been sized with a bushing that is 0.001 smaller than what it takes to hold a bullet.
If you think about what this does, it sorts cases according to two factors...
1) case to case variations in neck hardness
2) case to case neck wall thickness variation
My guess is that this process will result in significantly more consistent seating pressure.
This was essentially my process for processing brass for F Class before I started running tight neck chambers and neck turning.
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If I might make a comment about the Peterson annealing line...
I get the same demarcation line on all my brass when I use my AMP annealer.
The brass sets exactly to the same depth between the induction coils and the amount of heat and time is exactly the same every time and spacific for that lot of cases.... All the more reason to buy several hundred cases in one lot because they do vary a bit from lot to lot though Peterson and Alpha are very good in their tolerances. That is why the last lot I bought 500 pcs so that I have consistancy over a long time without having to work up new load/settings... AND I don't have to reload so often!
Not too keen on that carbide burr as it is really easy to remove too much material and the chamfer will be still too acute. Perhaps chamfering the case mouth to a knife edge if used too vigorously.I have to ask ChuckWagon about a couple things...
The first is how you are chamfering the inside case mouth. The cheap neck deburr tools sold for this purpose do not in my mind have an ideal cutting angle and worst yet, they are not sharp enough to do a really nice job of it. I've been using 1/4" shank cone shaped carbide burrs to do the inside and feel it is a game changer for how it improves seating pressure.
If you do this lightly after stainless media tumbling you will not have any problems with dented case mouths.
The next thing is with regard to sizing bushings...
What is your sizing process?
If you are currently not neck turning then any neck wall stock variability will transfer to the inside and influence neck tension variability.
The next variable is case to case hardness variability. This affects spring back.
Here's a trick you can try that will almost certainly sort out the problem... I hope I'm clear enough for you to understand.
This works best with a neck only sizing die. An FL die will not allow you to feel this, but it still occurs.
You need to size and resize the necks in 0.001" increments, not just one pass for all cases. Neck turned brass will reduce the range of bushing sizes you will need.
Start with a neck sizing bushing that is at least one size too large to hold a bullet after sizing. With a normal factory chamber you will notice the case is easy to draw out of the bushing. This is because reducing a neck by 0.012 diameter in a single pass creates a taper to the neck side wall. When you draw the case out of the bushing there will be no resistance and you can feel it. The next step will reduce that neck taper.
Now size the cases again with the next bushing smaller. This time, you will feel the resistance when you retract the ram as the neck side wall is now parallel after sizing.
At this point using a bullet as a go/nogo gage, set aside any case that is tight enough that you cannot push the bullet into the neck by hand. Keep those in one bowl and all lose mouth cases in a separate bowl.
After you run the batch, reduce the neck sizing bushing one more size, and run all the cases from both bowls again.
At this point, the bowl that was already tight with a bullet has at least 0.001" neck tension and the side walls are parallel. These are ready to load.
Repeat this process until all cases have been sized with a bushing that is 0.001 smaller than what it takes to hold a bullet.
If you think about what this does, it sorts cases according to two factors...
1) case to case variations in neck hardness
2) case to case neck wall thickness variation
My guess is that this process will result in significantly more consistent seating pressure.
This was essentially my process for processing brass for F Class before I started running tight neck chambers and neck turning.
I would recommend the K&M tapered case mouth reamer inside, only about 17* taper and the cutter blades are sharp as a serpent's tooth and make an easy job of it. Also the cutter is depth adjustable and centres with a long pin/rod through the flash hole.
I think this is something important that rarely gets mentioned here: the need to measure CBTO on each seated round and to adjust for consistency. You’d get the impression from the interweb mavens that because their process is so refined, and “neck tension” so controlled, they adjust their die on round 1 then seat the next 100 without checking, and their CBTO variance is all within .0005
Dusty Stevens
Shiner
If you get a flyer, sit that brass aside and mark it. If it does it again chunk that brass. Are you shooting over wind flags? I think this post went way out in left field
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