expander mandrel

[knguyen]

first of all, happy holidays to all members
question is :
background: i use redding full length F bushing die, redding competition seating die
neck bushing using .266 bushing

i am learning each day as i read.
my question is, i have new brass(Lapu 6BR brass),
my present process is full length size and at same process use .267 bushing inside the die,then seat bullet using redding competition seating die
I have been reading that alot people use Expander Mandrel(i.e: sinclair or K&Mexpander mandrel): then load the bullet:
question is, if you use the expander mandrel,then can you skip or do not need the bushing (i.e.: .266 size?
i know that the expander mandrel helps straightern out walls and any small dings in the wall.

i am confused, if you choose the expander mandrel on the brass(is it only used on new brass only? or do you use it with each loading?)
when to use expander mandrel, when not to use expander mandrel?

sorry if i seem bit confused, I am confused.
just learning to make better more precise rounds

any clarification or teaching points would be greatly appreciated.

thanks
khanh

 

[Chappy]

I only use an expander die on new brass to iron out any imperfections in the neck. Then clean up the neck with a neck turning tool. After firing that brass, use a bushing that will give you 0.001"-0.002" of NT on the bullet. Don't over work the brass anymore than you have to.

 

[SWRichmond]

I realize a strong possibility exists that I'm doing it wrong but here is what I am doing. I would also appreciate comments on my technique and observations.

I have found that even after next turning brass I still can feel substantial differences in bullet seating force and so I use an expander mandrel on every case prior to seating. this I have found greatly reduces the number of cases on which I experience tension seating force differences but even this does not eliminate those differences.

I would also be really interested to hear other shooters' comments on case neck cleaning.

 

[ShootDots]

I realize a strong possibility exists that I'm doing it wrong but here is what I am doing. I would also appreciate comments on my technique and observations.

I have found that even after next turning brass I still can feel substantial differences in bullet seating force and so I use an expander mandrel on every case prior to seating. this I have found greatly reduces the number of cases on which I experience tension seating force differences but even this does not eliminate those differences.

I would also be really interested to hear other shooters' comments on case neck cleaning.

I T-Totally understand what you are saying! I have "cured" that problem by doing it this way:

Take the expander mandrel and open the VIRGIN brass. I do this by running the brass over the mandrel and turning it 1/3 turn and do it again, spin it again 1/3 and do it again and spin it 1/3 turn and do it again. I know this sounds like a lot but it takes just 3-4 seconds to do the "extra" spinning. This evens it out pretty well. Then I turn my necks down, put a minuscule chamfer on the outside and a normal one on the inside. After ALL your brass is turned, ANNEAL ALL that Virgin brass. Then go ahead and run it back into the mandrel again, prime and load. You will just about ELIMINATE the huge variances in seating depth pressure doing this.

I know>>Virgin brass is already annealed from the factory! Why do it again? Just try my way ONE TIME, if you don't like it>>>don't do it again. However, I know what you will be doing from here on out IF you try it the way I do it..

 

[CatShooter]

I know>>Virgin brass is already annealed from the factory! Why do it again? Just try my way ONE TIME, if you don't like it>>>don't do it again. However, I know what you will be doing from here on out IF you try it the way I do it..

I anneal ALL brass that I neck turn. Turning work hardens the neck and will cause problems later. I learned it the hard way, when I turned and loaded a ton of ammo one October, for a PD shoot the following summer and discovered in South Dakota, that ~30% of my rounds had "T" splits in the necks

 

[amlevin]

Every shooter develops their own methods for case prep.

If one can neck turn their brass to EXACTLY the same thickness, and anneal it so there is EXACTLY the same amount of spring-back, then they SHOULD get EXACTLY the same Neck Tension.

In reality this rarely happens.

I find that it's more expedient and results are great when I turn then use a bushing that sizes just a 'thou" or so more than what calculations would call for. I then run a Sinclair expander mandrel through all the sized case necks.

This allows for minimal working of the brass and when I seat bullets they all seat with the same amount of force (by feel).

Even neck tension is the "Destination". There are many "Routes" to it. Pick one that fits your situation and enjoy.

 

[SWRichmond]

Thanks a bunch for the feedback, I truly appreciate it.

I am going to anneal after turning (makes sense, though I haven't been doing that), and continue using the expander mandrel on sized cases. I already use a Sinclair bushing die set with appropriately sized bushings. Next time I start with virgin brass I will expand and spin as first step.

Also just beginning experimenting with use of dry neck lube on bullets before seating.

 

[bow shot]

Being a former annealing hater/sceptic.. I now anneal after every firing. Why? I could tell that, while collet sizing the mandrel/case drag was quite different case-to-case, even if I brought the cases through the die several times... even with virgin brass. Same thing for required seating force (Wilson dies). Some bulltets slipped in gently, others took noticeable force. I also found that some bullets would pull out of the case when being un-chambered (slight jam). I also noticed inconsistent "grip" on the turning mandrel, even if passed through the expander die several times.

All better now. Lapua brass is where I first went, "huh"... haven't done much with the other stuff....

Virgin brass gets it too before turning.

 

[Joe R]

ShootDots said:

I T-Totally understand what you are saying! I have "cured" that problem by doing it this way:

Take the expander mandrel and open the VIRGIN brass. I do this by running the brass over the mandrel and turning it 1/3 turn and do it again, spin it again 1/3 and do it again and spin it 1/3 turn and do it again. I know this sounds like a lot but it takes just 3-4 seconds to do the "extra" spinning. This evens it out pretty well. Then I turn my necks down, put a minuscule chamfer on the outside and a normal one on the inside. After ALL your brass is turned, ANNEAL ALL that Virgin brass. Then go ahead and run it back into the mandrel again, prime and load. You will just about ELIMINATE the huge variances in seating depth pressure doing this.

I know>>Virgin brass is already annealed from the factory! Why do it again? Just try my way ONE TIME, if you don't like it>>>don't do it again. However, I know what you will be doing from here on out IF you try it the way I do it..

knguyen,
I've seen Ben shoot. I would encourage you to do his way. I'm going to from now on.

Kindest regards

Joe

 

[SDDasher]

I realize a strong possibility exists that I'm doing it wrong but here is what I am doing. I would also appreciate comments on my technique and observations.

I T-Totally understand what you are saying! I have "cured" that problem by doing it this way:

Take the expander mandrel and open the VIRGIN brass. I do this by running the brass over the mandrel and turning it 1/3 turn and do it again, spin it again 1/3 and do it again and spin it 1/3 turn and do it again. I know this sounds like a lot but it takes just 3-4 seconds to do the "extra" spinning. This evens it out pretty well. Then I turn my necks down, put a minuscule chamfer on the outside and a normal one on the inside. After ALL your brass is turned, ANNEAL ALL that Virgin brass. Then go ahead and run it back into the mandrel again, prime and load. You will just about ELIMINATE the huge variances in seating depth pressure doing this.

I know>>Virgin brass is already annealed from the factory! Why do it again? Just try my way ONE TIME, if you don't like it>>>don't do it again. However, I know what you will be doing from here on out IF you try it the way I do it..

Ben
Do you Fireform for your Dasher first before the procedure above? If not, how do you get enough neck tension to push the shoulder forward?