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Mandrel sizing for consistent neck tension
- Thread starter sbruni
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BrentM
Well-Known Member
If you have concentricity issues then you may need to look at the bullet seating process primarily. I used comp dies with floating heads but I still turn 1/3 and I press the bullet in. Just a habit but in the end I have had less than .002 run out as a result and never have to mess with ammo truing anymore.
MoaFlat
Well-Known Member
- Joined
- May 16, 2017
- Messages
- 78
Couple of things to ponder.... IMHO: to have .001 to .0015" neck tension is ideal..
Determine what means 'Soft' annealed: Consistent Springing back of neck and landing back to a uniform neck size. Hint: The softer the brass then the less tensile spring back. The degree of random hardness spring back final dimension difficult to control.
Brass Composition will affect the tensile degree of spring back- so neck tension uniformity wool take that into consideration.
( not meaning one or other better or worse - only the uniformity of spring back must be sought)
Annealing after every firing necessary for match uniformity only takes one not uniform. Example could be same brass but from different pressure load firing.
Checking each neck OD for uniformity providing same neck thickness constant or uniform helps heaps. Better to neck turn or ID ream to achieve this....ever try to blow up a thick Wall balloon? Much harder than thin one...same thing - wall thickness important. Also ductility or softness important, remember wiggling the balloon end so it blows up considerably easier - UNIFORMITY first above all else.
I have found that some thin walled brass that was under high pressure load would not anneal to "softness uniformity" as the others processed same way... and refused to return to same uniform neck OD until they were shocked annealed...dropped in water to quench. This shock returned them to behave as the rest of the lot. So you sort them and shock quench those afterwards.
Oh yes last thing keep in mind if your radius measurements single wall brass neck thickness are X2 for diameter (? At least that is my assumption)
Determine what means 'Soft' annealed: Consistent Springing back of neck and landing back to a uniform neck size. Hint: The softer the brass then the less tensile spring back. The degree of random hardness spring back final dimension difficult to control.
Brass Composition will affect the tensile degree of spring back- so neck tension uniformity wool take that into consideration.
( not meaning one or other better or worse - only the uniformity of spring back must be sought)
Annealing after every firing necessary for match uniformity only takes one not uniform. Example could be same brass but from different pressure load firing.
Checking each neck OD for uniformity providing same neck thickness constant or uniform helps heaps. Better to neck turn or ID ream to achieve this....ever try to blow up a thick Wall balloon? Much harder than thin one...same thing - wall thickness important. Also ductility or softness important, remember wiggling the balloon end so it blows up considerably easier - UNIFORMITY first above all else.
I have found that some thin walled brass that was under high pressure load would not anneal to "softness uniformity" as the others processed same way... and refused to return to same uniform neck OD until they were shocked annealed...dropped in water to quench. This shock returned them to behave as the rest of the lot. So you sort them and shock quench those afterwards.
Oh yes last thing keep in mind if your radius measurements single wall brass neck thickness are X2 for diameter (? At least that is my assumption)
sjones
Well-Known Member
These are not carbide, but you can get any size you want to set necks.
http://www.xxicsi.com/expander-mandrels.html
http://www.xxicsi.com/expander-mandrels.html
65WSM
Well-Known Member
I use mostly Wilson arbor size dies, they size half to 3/5 of the neck so the unsized portion will help center the cartridge in the chamber. I use Forster dies when I need additional shoulder bumping and butt sizing. I have found Forster dies create more concentric cases than Redding or Whidden dies. Their seaters often will outperform (concentricity) Wilson seaters as well. Forster will provide different size button diameters if you call them.
Frank Kalisz
Well-Known Member
1) who's mandrels do you use (stainless or TiN coated)?
I use 21st Century TiN coated mandrel.
2) Do you inside lube before?
I dip my case necks in Imperial Dry Lube.
3) Do you used the expander Mandrel? Or Turning?
I use an expander mandrel. It's one thou under bullet diameter.
4) what relative size Bushing do you use?
I use a custom honed Forster full length die sized at factory to 4 thou under loaded neck diameter for my particular brass. I size my brass without the expander spindle. For my 308win Lapua brass, my custom honing size came out to 0.3340".
5) Any other keys to success?
I always anneal before sizing. I use 550degC salt bath.
I use 21st Century TiN coated mandrel.
2) Do you inside lube before?
I dip my case necks in Imperial Dry Lube.
3) Do you used the expander Mandrel? Or Turning?
I use an expander mandrel. It's one thou under bullet diameter.
4) what relative size Bushing do you use?
I use a custom honed Forster full length die sized at factory to 4 thou under loaded neck diameter for my particular brass. I size my brass without the expander spindle. For my 308win Lapua brass, my custom honing size came out to 0.3340".
5) Any other keys to success?
I always anneal before sizing. I use 550degC salt bath.
misterc01
Well-Known Member
Welcome to the dark arts of reloading! Been in the same boat you are - go slow, take your time and make sure whatever you do, it done safely! study, research and if you can, find an experienced reloader for some advice and mentoring. I also learned that anything you read or hear, you are free to try it or ignore it or modify so whatever you do, works best for you. Goals: IMHO safety and Consistency. Have fun!
misterc01
Well-Known Member
If you are having concentricity issues and are using a quality seating die, might want to get and use a concentricity gauge. My final step is concentricity check with a Hornady gauge, and adjust to get under .002 which in my application is all I need. Having said that, using a Forster micrometer seating die, I am usually well under .001.
Frank Kalisz
Well-Known Member
I use a Forster Benchrest Seater Die (without micrometer) for an inexpensive good quality seating die that gets good concentricity.
On subject of concentricity guage, you don't have to spend a lot of money for that either. I'd like to share a very cheap and successful homemade project. It just takes a $7 chinese 0.01mm gauge, a $10 magnetic gauge holder, 4ea 3/4-inch ball bearings, a short 2x4 bolted on a steel plate, and a small nail.
Here's a link that shows something similar to what I did.. It was pretty easy.
On subject of concentricity guage, you don't have to spend a lot of money for that either. I'd like to share a very cheap and successful homemade project. It just takes a $7 chinese 0.01mm gauge, a $10 magnetic gauge holder, 4ea 3/4-inch ball bearings, a short 2x4 bolted on a steel plate, and a small nail.
Here's a link that shows something similar to what I did.. It was pretty easy.
65WSM
Well-Known Member
I have a 6.5-06 Ackley (tight turn the necks chamber), a couple of 6.5 WSMs, 6.5 Creed, four .270 WSMs, and a 7mm Rem Mag I am loading for this Fall. I try to target for 0.0015 of neck tension and use Wilson or Forster seaters. I agree with MOAFlat. I also anneal brass every third cycle. Remember to polish the inside of the necks. No naked bullets. Shoot coated bullets.
IHFarmer07
Well-Known Member
Haha thanks!! I've kind of have learned a lot here and other forums, I did start out with a family member with reloading and he had some good things to learn from but some of the stuff he had was not consistent enough or good enough to do what I was wanting to do, he mainly took what grouped the best and went. Me I wanted to go far, so es/sd mattered. I think I made a good choice picking a small caliber to start with(.224 Valkyrie) as its reasonable cheap but I'm slowly migrating to other calibers I have. Ya I've learned a while back to go slow sizing to let the brass have time to conform and also seating. I learned the hard way to get a good scale first off, wife said I could buy a good one so I don't blow my face off, thought I better not argue and get an fx120i, forester co-ax.....I have the tools to make quality rounds just not the experience yet, but I'm getting there!!!! Thanks Pete
IHFarmer07
Well-Known Member
I have a Sinclair concentricity gauge, forester FL and micro seater. Love the forester dies, good price excellent quality. Will have to buy more forester dies, been reloading my 30-06 and the freebore is so long that the Barnes ttsx can't be loaded out no more then .100" or else I'm about out of bullet in the case, (waiting on Barnes to email me back on this) but years ago before I knew what I was doing I bought a set of lee dies and the brass has a lot of runout, so I'm either going to get forester dies or figure something out with the lee's.
How do you "adjust" you concentricity on loaded rounds, turn the shell 1/3 of a turn and run it in the seating die and then another 1/3, and another 1/3 then done?
