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Lee Collet Dies vs Mandrel Expander

Afkirby

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Dec 21, 2009
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Does anyone have experience using lee collet dies to set case mouth diameter vs a mandrel expander? I've got a forster die with the expander ball removed and I plan on using a mandrel to set the case mouth for .002 bullet tension, a friend is planning on using the lee collet die with a custom mandrel to achieve the same goal. Any benefits or drawbacks from using the collet die?

-Kirby
 
Little more data on this. We’re both planning on using LC brass so neck wall thickness will probably vary. And we’re trying to avoid turning necks while getting consistent ID and bullet tension. My plan is to use a bushing die without a bushing to bump the shoulder back and the then size the neck with the Lee collet die. I’m not even sure if that’ll work, still waiting on some parts to test it out.

-Poptart
 
I had good luck full length re-sizing with a Redding die without the expander and then using the Lee collet die to neck size my 260 Lapua brass. I had really consistent neck tension with that.
 
Question that 260284 sort of hit on. I had thought that the lee collet was only for sizing down around the mandrel; taking a fired neck and squeezing it down.

So one could run it in a full length die and the lee would open the neck back up to whats necessary, acting the part of a mandrel die? Or was your redding die a bushing die and not a normal full length die so it acted as a body die and wasnt touching the neck?
 
I process my LC 5.56, LC 7.62 and Hornady 6.5cm semi auto brass on my Dillon 650 this way. My brass prep toolhead consists of a Universal depriming die in station 1, then either a Dillon FL Sizing Trim die or Forster FL sizing die with the expander rod removed if Im not trimming in Station 4 then a 21st Century TiN expander mandrel in Station 5 that sets .002 neck tension. This produces extremely accurate ammo with 0.0005 - 0.001 runout.
 
Little more data on this. We’re both planning on using LC brass so neck wall thickness will probably vary. And we’re trying to avoid turning necks while getting consistent ID and bullet tension. My plan is to use a bushing die without a bushing to bump the shoulder back and the then size the neck with the Lee collet die. I’m not even sure if that’ll work, still waiting on some parts to test it out.

-Poptart

I have only been reloading for a short while now (308 and 223 in the near future) and have not needed to bump the shoulder yet after about 6 or 7 firings. I have just been using the lee collet neck sizer for its simplicity and I have been having good results. I have noticed that some of my rounds are started to require slightly more force to chamber, which I assume is because the shoulders need to be bumped back a bit.

In an effort to avoid neck turning, my plan is to pick up a Forster bushing bump die, and remove the bushing. I will set it up to bump the shoulders .001-.002", then run them through my lee collet die like normal. I figure I will only have to bump the shoulders every 4-6 firings given my current pattern. I see no reason why this wouldn't work, and why it wouldn't produce good results. If I decide to pick up neck turning and bushing neck sizing down the road, I will be all set with the Forster die.

Someone correct me if I'm wrong, but I believe that the collet neck sizer works the case neck significantly less than if I were to use a bushing neck die, which should improve brass life, or allow more of an interval between having to anneal the brass.
 
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I process my LC 5.56, LC 7.62 and Hornady 6.5cm semi auto brass on my Dillon 650 this way. My brass prep toolhead consists of a Universal depriming die in station 1, then either a Dillon FL Sizing Trim die or Forster FL sizing die with the expander rod removed if Im not trimming in Station 4 then a 21st Century TiN expander mandrel in Station 5 that sets .002 neck tension. This produces extremely accurate ammo with 0.0005 - 0.001 runout.

Do you have any experience with the just normal SS mandrels? Wondering if the coating is worth while.

Looking to do the same sort of process on a Hornady LNL AP. Another question do you do any cleaning of brass pre sizing?

Thanks I feel like I am always asking you questions.
 
Either system will do what you are asking, custom mandrels can get pricey, plus size needs to be specified. If you think about it controlling from the outside would be simpler. Sometimes measured neck tension doesn't mean squat, where felt neck tension does.
 
I would think that the bump die with a lee collet would would work the brass less than a full length sizer and a mandrel. The full length sizer is going to be squeezing the neck undersize for the mandrel to bring back up, while the collet would size it directly without overworking the brass.
 
I would think that the bump die with a lee collet would would work the brass less than a full length sizer and a mandrel. The full length sizer is going to be squeezing the neck undersize for the mandrel to bring back up, while the collet would size it directly without overworking the brass.

Then again, a FL bushing die with correct bushing w/o expander will do all you are asking in one pass, lol
 
Question that 260284 sort of hit on. I had thought that the lee collet was only for sizing down around the mandrel; taking a fired neck and squeezing it down.

So one could run it in a full length die and the lee would open the neck back up to whats necessary, acting the part of a mandrel die? Or was your redding die a bushing die and not a normal full length die so it acted as a body die and wasnt touching the neck?

My Redding die is the basic Redding die. I just pulled the expander and use it to full length size/ bump the shoulder. I then use the lee collet to get consistent neck tension.
 
Then again, a FL bushing die with correct bushing w/o expander will do all you are asking in one pass, lol

That is what I am trying on my 6.5 Creedmoor brass for my new barrel. I am using the Hornady Match Grade full length bushing die without expander ball.
 
I use a body die to set shoulder and a collet to set neck.
You can pull the bushing out of the die and it as a body die.
Thats what I did at first after I saw what the Lee collet was capable of.
 
I'd use a bushing, but I don't feel like neck turning brass to get the consistency that would require.

Explain why you'd need to turn necks if you use a bushing die, I've ran them for 15+ yrs and never felt the need. There are times where a bushing die can be a disadvantage, as in over sized neck dia in the chamber, and a bushing will not fully size a neck and it becomes a donut factory, but that can be controlled by knowing what reamer will be used to chamber the gun.
 
I process my LC 5.56, LC 7.62 and Hornady 6.5cm semi auto brass on my Dillon 650 this way. My brass prep toolhead consists of a Universal depriming die in station 1, then either a Dillon FL Sizing Trim die or Forster FL sizing die with the expander rod removed if Im not trimming in Station 4 then a 21st Century TiN expander mandrel in Station 5 that sets .002 neck tension. This produces extremely accurate ammo with 0.0005 - 0.001 runout.

pandom, Is the mandrel your last step in case prep prior to seating or do you run the case through a bushing die at some point between brass prep and loading? If the mandrel is your last step was there a noticeable difference downrange when you switched from focusing on truing the inside diameter of the neck as opposed to the outside with a bushing die in the last station before seating?
 
Explain why you'd need to turn necks if you use a bushing die, I've ran them for 15+ yrs and never felt the need. There are times where a bushing die can be a disadvantage, as in over sized neck dia in the chamber, and a bushing will not fully size a neck and it becomes a donut factory, but that can be controlled by knowing what reamer will be used to chamber the gun.

I'm mostly reloading 223 with lake city brass, I assumed that using a bushing would push inconsistencies in the case neck from the OD to the ID thus creating different neck tension from round to round.
 
I'm mostly reloading 223 with lake city brass, I assumed that using a bushing would push inconsistencies in the case neck from the OD to the ID thus creating different neck tension from round to round.

So many trains of thought on this, would not running a mandrel on the inside push crap outward, leaving voids in the surface area of gripping surfaces? I believe firing brass irons out inconsistencies in the neck.
 
pandom, Is the mandrel your last step in case prep prior to seating or do you run the case through a bushing die at some point between brass prep and loading? If the mandrel is your last step was there a noticeable difference downrange when you switched from focusing on truing the inside diameter of the neck as opposed to the outside with a bushing die in the last station before seating?

The mandrel is the last step on my case prep toolhead. My loading toolhead consists of a decapping die in station 1 to push out any corn cob that might be in the flash hole, prime and powder drop in station 2, seat bullet in station 4.

I can tell you that my runout is consistently .0005-.001 with the mandrel where it was .004-.007 runout with a bushing...As stated before, how much that affected groups downrange I dont know because I never did extensive testing with LC 5.56 or 7.62 brass. I did do a head to head comparison of Lapua 6.5x47L and 260rem brass though. 25 were sized with a Forster FL sizing die and TiN mandrel and showed .001 or less and the other 25 were sized with a Redding neck sizing die with bushing and no expander ball that showed .005-.007 runout and I can tell you the group size at 100yds showed no difference.

I have different processes for different rifles. But my semis are all sized on the Dillon XL650 as stated above with the mandrel. And at $8.95 for steel and $18.95 for a TiN 21st Century mandrel they are cheaper than bushings..

My custom bolt guns are sized with a Redding neck sizing die with a TiN bushing with expander and accuracy is excellent as evident in my 223 barrel review thread... Groups produced under 0.1" so I dont see the runout being the huge issue everyone makes it downrange in my testing. I do use a Forster FL sizing die when I need to bump the shoulder back.
 
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Do you have any experience with the just normal SS mandrels? Wondering if the coating is worth while.

Looking to do the same sort of process on a Hornady LNL AP. Another question do you do any cleaning of brass pre sizing?

Thanks I feel like I am always asking you questions.

I have both K&M Precision steel mandrels and 21st Century TiN mandrels in the exact same sizes. I was using the K&M mandrels which required me to every 10 cases or so put Umperial sizing lube on the mandrel as it would be much harder to pull through the case on the up stroke. I dont have to use any lube with the TiN mandrels, they are smooth as butter which is the main reason I switched. They both get the job done though, the TiN just save me time and hassle.

I tumble my brass in corn cob before processing it. I do not even deprime anymore. I have a Thumblers Tumbler B, Rebel 17 ss tumblers, and I have a ultrasonic and I have 2 dry media tumblers. I have done them all. I have done numerous testing and I have found zero advantage in accuracy or SD's SS tumbling, ultrasonic cleaning, depriming before tumbling, etc. Because of this I now throw my brass into the corn cob for an hour or 2, depriming and size all at the same time then throw them in corn cob again to remove the lube.
 
I have both K&M Precision steel mandrels and 21st Century TiN mandrels in the exact same sizes. I was using the K&M mandrels which required me to every 10 cases or so put Umperial sizing lube on the mandrel as it would be much harder to pull through the case on the up stroke. I dont have to use any lube with the TiN mandrels, they are smooth as butter which is the main reason I switched. They both get the job done though, the TiN just save me time and hassle.

I tumble my brass in corn cob before processing it. I do not even deprime anymore. I have a Thumblers Tumbler B, Rebel 17 ss tumblers, and I have a ultrasonic and I have 2 dry media tumblers. I have done them all. I have done numerous testing and I have found zero advantage in accuracy or SD's SS tumbling, ultrasonic cleaning, depriming before tumbling, etc. Because of this I now throw my brass into the corn cob for an hour or 2, depriming and size all at the same time then throw them in corn cob again to remove the lube.

I've actually been thinking a lot about testing both the mandrel having less runnout theory and the affect or lack there of depriming prior to tumbling. Thanks for confirming.
 
The mandrel is the last step on my case prep toolhead. My loading toolhead consists of a decapping die in station 1 to push out any corn cob that might be in the flash hole, prime and powder drop in station 2, seat bullet in station 4.

I can tell you that my runout is consistently .0005-.001 with the mandrel where it was .004-.007 runout with a bushing...As stated before, how much that affected groups downrange I dont know because I never did extensive testing with LC 5.56 or 7.62 brass. I did do a head to head comparison of Lapua 6.5x47L and 260rem brass though. 25 were sized with a Forster FL sizing die and TiN mandrel and showed .001 or less and the other 25 were sized with a Redding neck sizing die with bushing and no expander ball that showed .005-.007 runout and I can tell you the group size at 100yds showed no difference.

I have different processes for different rifles. But my semis are all sized on the Dillon XL650 as stated above with the mandrel. And at $8.95 for steel and $18.95 for a TiN 21st Century mandrel they are cheaper than bushings..

My custom bolt guns are sized with a Redding neck sizing die with a TiN bushing with expander and accuracy is excellent as evident in my 223 barrel review thread... Groups produced under 0.1" so I dont see the runout being the huge issue everyone makes it downrange in my testing. I do use a Forster FL sizing die when I need to bump the shoulder back.

I just read through that 223 barrel review thread. That was pretty impressive results. Great info to get out there as well, your right about the market screaming in need for standardization and interchange systems that do not depend on a smiths work load.

On the "custom bolt guns sized with Redding neck sizing dies with an expander" mentioned above what size TiN are you running for 6mm Lapua brass?

What is the your personal working theory on full sizing to bump the shoulder back?
 
I don't shoot 6mm Lapua so no idea..I bump.the shoulder. 001-.0015 for bolt gun brass and .003 for semi auto with Forster FL sizing dies honed.
 
I can tell you that my runout is consistently .0005-.001 with the mandrel where it was .004-.007 runout with a bushing...

4 thou is enough in my guns to impact precision, so .007 is a real problem. I use a Forster FLSD + mandrel unless I have a reason to go the bushing die route. I have some before and after Redding bushing die concentricity numbers I'll put up whenever I get off my lazy ass. Bottom line is that most often, I see the Redding bushing die lowering runout but it's not competitive with the Forster FLSD regarding concentricity.

 
4 thou is enough in my guns to impact precision, so .007 is a real problem. I use a Forster FLSD + mandrel unless I have a reason to go the bushing die route. I have some before and after Redding bushing die concentricity numbers I'll put up whenever I get off my lazy ass. Bottom line is that most often, I see the Redding bushing die lowering runout but it's not competitive with the Forster FLSD regarding concentricity.

TripleBull, do you full length size the case every time or just when needed?
 
So many trains of thought on this, would not running a mandrel on the inside push crap outward, leaving voids in the surface area of gripping surfaces? I believe firing brass irons out inconsistencies in the neck.

People using expanders aren't worried about the outside of the neck be perfectly round. Its not the part that grips the bullet. People controlling neck tension from the outside, are worried about the O.D of necks being perfect though. For a couple reasons. The difference can be in the thickness of the brass from one side of the case to the other. That would never iron out from firing. It would also cause a lot of runout if the neck was not turned, and it was sized with a bushing die with the mandrel removed.


 
People using expanders aren't worried about the outside of the neck be perfectly round. Its not the part that grips the bullet. People controlling neck tension from the outside, are worried about the O.D of necks being perfect though. For a couple reasons. The difference can be in the thickness of the brass from one side of the case to the other. That would never iron out from firing. It would also cause a lot of runout if the neck was not turned, and it was sized with a bushing die with the mandrel removed.

I have a 21st Century lathe, all the bells and whistles, for the type of shooting or shooters this forum caters too, I have yet to see the overall benefits of neck turning brass. My runout with Whidden bushing dies w/o the expander ball is less than .001". I've shot runout to .006" and never saw adverse effects downrange.
I just said it is easier to control neck tension from the outside, and it is. Most don't have custom mandrels where they can swap and get it right,
I hear pushing inconsistencies to the outside, brass would have to be red hot for this, you may make a straighter hole?
Here's some mandrels for 6mm, the one outside the sleeve is carbide, it's 65 bucks, most wont pay for this
 

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