Tell me about mandrels? Use of, pro & con

[R. Cram]

i like to use lee collet die and body die

if you want to have concentric cases, nothing is even close to the lee collet dies, every one I have puts out cases within .001 every time. Don't know if that is necessary but no lube to put on and take off and the concentricity gauge doesn;t hardly move. I am going to load up for tomorrows match in a minute and will make 22 rounds for the 600 yd line in about 1/2 hour. The computor would not let my post this so I went and loaded tomorrows 22 shots for the match and I lied, It took me 37 minutes to check oal to the lands with 140 amax and size 27 cases I shot in todays match in the collet die by Lee and prime the cases and weigh the charges and seat the bullets, I changed the seating depth by020 and will see if I can tell the difference tomorrow

 

[fire814]

if you want to have concentric cases, nothing is even close to the lee collet dies, every one I have puts out cases within .001 every time. Don't know if that is necessary but no lube to put on and take off and the concentricity gauge doesn;t hardly move. I am going to load up for tomorrows match in a minute and will make 22 rounds for the 600 yd line in about 1/2 hour. The computor would not let my post this so I went and loaded tomorrows 22 shots for the match and I lied, It took me 37 minutes to check oal to the lands with 140 amax and size 27 cases I shot in todays match in the collet die by Lee and prime the cases and weigh the charges and seat the bullets, I changed the seating depth by020 and will see if I can tell the difference tomorrow

Does the Lee collet give you good neck tension ?

 

[Tiny Tim]

I use a .002 - .003 smaller bushing to start with. And that's where it usually ends up. If the brass sits for a while before I load it I'll run a pin gauge in the neck to check the ID. Sometimes I'll do that after I run a mandrel through it.

Here is another theoretical advantage(?) of a mandrel. Since it must overcome the yield point of the brass to expand it, it should theoretically get tighter rather than looser over time if it is going to move.

 

[Barrelnut]

Austin said he doesn't have an expansion ball on his decapping pin on the sizing die. Austin: "A case just goes straight up into the SAC sizing die, so I'm just squeezing down the outside diameter of the neck, and then I seat a bullet shortly after that." He doesn't use a neck mandrel or anything else to set the inside diameter of the neck. Austin: "Nope, no expander or mandrel at all. The bullet sets the insider diameter of the case neck whenever I seat it."

If your case trimmer uses pilots, the pilots may not fit, if the case neck has not had an expander button or mandrel run through it first.

 

[Alibiiv]

I can understand why a mandrel might be better than the ball you pull back through the neck after depriming and sizing. But why do you guys think a mandrel is better than bushing dies? One sets neck tension by outside compression and the other by inside expansion.

I'm trying to decide if I should upgrade from the way I learned 60 years ago.

Might want to consider upgrading from way back when you started 60 years ago. I undid what I learned 62 years ago. If you follow some of the replies the reason is explained in many of them.

 

[R. Cram]

Does the Lee collet give you good neck tension ?

the fingers on the collet get squeezed over a shaft which fits inside the neck of the case so if you are not getting enough neck tension chuck the shaft up in a drill and spin it putting sandpaper to the outside and reduce the diameter by a thousandth or so and try it again or call lee and they can give you one with a lesser diameter. these things work better than any other I have tryed for neck concentricity, all the ones I did last night were .001 out at the most.

 

[fire814]

Great, Thankyou

 

[Mike6158]

Here is another theoretical advantage(?) of a mandrel. Since it must overcome the yield point of the brass to expand it, it should theoretically get tighter rather than looser over time if it is going to move.

Some brass, like Peterson (7mm Rem Mag), takes a few firings before it settles down, even with annealing. Some, like Lapua, is good from the beginning. They don't make 7mm Rem Mag brass. I've seen the Peterson brass spring back. It took 4 firings before it stopped moving after sizing.

 

[DMP25-06]

Does the Lee collet give you good neck tension ?

I first tried using the mandrel that came with the die , but found that there was not sufficient neck tension to hold the bullet securely , I could push the bullet into the case with my thumb . So , I measured the diameter of the mandrel , and then contacted Lee Precision to purchase a mandrel that was .003" smaller than original (because I intended to have cartridges in my magazine while hunting , and I did not want rifle recoil to jamb the bullets back into the case).

On other rifles that I only loaded single shot , I ordered .002" smaller mandrels .

At that time , about 10-12 years ago , the new undersized mandrel cost $4.50 from Lee Precision .

 

[tribb]

I have Redding Competition 3 Die Neck Sizing Set in .300 Win. Magnum . This die set has a "Body Die" that is used to full-length resize the cartridge body ; a Micrometer Adjustable Neck-Sizing Die that uses bushings to allow you to select the amount of neck tension , with a de-capping rod and expander ball (That I have removed to keep from pulling back through cartridge neck) ; and a Micrometer Adjustable seating die .

I use a Lee Universal De-Capping die that I use to remove primers from all of my cartridge cases as my 1st operation of reloading .
Step 2 , I use the Redding Body Bushing Die to full-length re-size the case .
Step 3 , I use the Redding Micrometer Adjustable Neck-Sizing Bushing Die to set my desired neck tension , with the de-capping rod and expander ball removed from the die .
Step 4 , I use a Lee Collett style Neck-Sizing Die , with a mandrel that I use to make the cartridge neck concentric (I ordered a .002" smaller mandrel , from Lee Precision , than the mandrel furnished in the original collet die) . Lee offers various size mandrels to allow you to maintain your desired neck tension , after using the Redding neck-bushing sizing die.
Step 5 , After priming and powder charging the cartridge cases , I seat the bullets using the Redding Micrometer Adjustable Seating Die , to my desired cartridge length .

It requires 2 additional steps in my reloading process , but I have never had any of my reloaded cartridges have any bullet run-out . They are perfectly straight .
I use a Lee Collet Neck-Sizing die with all of my different cartridges that I reload .

Very cheap prices for the Lee Precision Universal De-Capping Die and Lee Collet Neck-Sizing Die . Less than $40.00 total for both .

I may not be doing my reloading in the accepted methods , but this works very well for me .

DMP25-06

Thank you