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Using a lee collet die for a mandrel

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Disfunctional_Engineer

Sergeant of the Hide
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Jul 27, 2020
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Anyone ever done this? The pin floats in the die so what I'm thinking is just put the die up some so that it doesn't use the collet on the neck. The order I'm thinking about right now is:

-Universal decapper (flash hole check)
-resize (no expander)
-size neck (collet die as mandrel)
-Charge (probably a home brewed charging die)
-seating

I may eliminate the universal decapper by eliminating the expansion function (use a 223 expander or turn it off) of a standard sizing die. The other thing is that this setup would be compatible with my LNL AP as a "one shot" system where I wouldn't need to use the press twice. I'd just throw deprimed/cleaned/pocked prepped brass in and run.

The only consideration I have that could significantly alter this is that I wouldn't have trimmed and I think I need to do that after the case is in its final shape. (e.g. between neck sizing and charging.) If that's the case then I may take the first steps and have another setup for the last two steps (3 if FCD is used) and I would probably end up on my Dillon 550.

Am I going up the wrong tree here? If the shape of the collet die's pin is a bit suboptimal that's not much of a concern as I'll just chuck er up in the lathe and do what I need to.
 
Maybe I read through that wrong but do you plan on FL sizing then using the collet die as only an expander or are you planning on neck sizing then using the collet die as an expander ?
If neck sizing the Lee collet neck dies are pretty damn good alone.
 
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I have been experimenting with this a bit lately,FLS without expander ball is kind of like a poor mans body die and has been working well enough in conjunction with a lee collet die. Another bonus is you don’t need to lube inside the neck, just brush out the loose soot and you can expand/seat away.

Brush out neck.
Lube cases.
FLS (shoulder bump) without expander ball.
Expand neck and decap with lee collet die set to a light squeeze on the neck.
Prime.
Add powder.
Seat bullet.
Wipe off lube and inspect assembled round.
Done.

I have lost no measurable consistency so far by doing it this way.
 
That's interesting and it doesn't sound altogether different from what I'm proposing to do. Where do you trim your brass at if you don't mind me asking? It also sounds as if you're pretty well eschewing cleaning as well?
 
I have been doing this method for years.
Full length size, no expander.
Mica the necks
Push casing up lee collet mandrel 2 times.
Tumble cases.

Fun fact..you can buy the Lee mandrels off
eBay and if you use rcbs standard dies the mandrel will slide right into die body and sticks out enough that the casing only contacts mandrel and not inner die.
 
Dave62677 said:
Pretty much u just use body dies then lee collet dies.
That’s what I do for the last 5 years.

I measure it with concentricity gauges and result were 0.001~0.002 runout

i sold all my bushing FL dies after~
Click to expand...

Have you had any issues doing it in that order? I used to bump with a body die followed by the collet die and brass that would chamber after bumping, I would no longer be able to close the bolt on after the collet die. Switched to collet die first then the body die and my issues went away.
 
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Chargerguy said:
Have you had any issues doing it in that order? I used to bump with a body die followed by the collet die and brass that would chamber after bumping, I would no longer be able to close the bolt on after the collet die. Switched to collet die first then the body die and my issues went away.
Click to expand...
I never have any issue. Make sure your dont screw down the collet die too further down. I normally random check headspace Before and after seat the bullet. I never had any surprises.

have you done any measurement after the collet die?
 
Disfunctional_Engineer said:
That's interesting and it doesn't sound altogether different from what I'm proposing to do. Where do you trim your brass at if you don't mind me asking? It also sounds as if you're pretty well eschewing cleaning as well?
Click to expand...

Brass trim (if it needs it) is done after FLS and collet mandrel, I have castings of several of my chambers and virgin brass necks are usually quite a way short of actual neck in the chamber. Because of this I don’t trim to SAAMI spec and keep neck length just short of my chamber, depending on brass quality and cartridge being shot this can mean brass gives out before regular trimming becomes necessary, but you do need to know YOUR chamber.

I don’t have the ability to trim brass based off a shoulder datum, so trimming based on overall brass length AFTER complete sizing keeps necks a lot more consistent than trim before sizing in my experience.

For cleaning my brass all I do is squirt a bunch of fired cases with carb cleaner and scrub them around in a rag, which is mainly to ensure there is no grit or marker residue to scratch up my dies or stick cases.
Inside of cases do not get touched apart from a brush through the neck and a quick tap on the bench to dislodge loose carbon.

Primer pockets are a 50/50 affair. I usually don’t bother, but sometimes I feel guilty and scrape the soot out. I can’t say clean pockets shoot any more consistently than fouled pockets.

I usually shoot steel rather than paper groups, but can say my current (lack of) cleaning regime has not measurably increased my group sizes one bit.
 
Chargerguy said:
Have you had any issues doing it in that order? I used to bump with a body die followed by the collet die and brass that would chamber after bumping, I would no longer be able to close the bolt on after the collet die. Switched to collet die first then the body die and my issues went away.
Click to expand...

Depending on how close you bump your shoulder and exactly how you measure your base to shoulder datum, collet sizing after FLS/body sizing can move the shoulder out as much as .003-.004 from non neck sized brass. Once this value is known (and known to be repeatable) you can bump your shoulders back further and let the collet die move them out again.
 
Body die and then Lee collet die for me as I figure the body die is going to have some influence on the shoulder and neck area. I always set the collet die in the press so that you use the full stroke of the press, therefore limiting the amount you can squeeze the neck. Push down too hard on a collet die and you can collapse the neck and shoulder completely.
 
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jagged77 said:
Push down too hard on a collet die and you can collapse the neck and shoulder completely.
Click to expand...

That is not at all how collet dies work. Push down too hard and you can stick a case yes, but you cannot collapse the shoulder with an in spec die.

A798C6C3-582A-405B-B47E-1AF228A6261A.jpeg
 
Shootin Stuff said:
That is not at all how collet dies work. Push down too hard and you can stick a case yes, but you cannot collapse the shoulder with an in spec die.
Click to expand...

You're absolutely right, I stand corrected. I have collapsed the odd case years when I started out using the collet die, but this was down to the case neck not entering the neck area of the die properly. A small amount of imperial lube fixes this problem.
 
dumb question, I notice some of you mention a "shoulder die." I'm presuming that's a FL die where the neck portion is oversized compared to the brass so it doesn't alter it?

Thinking I'd try to take a 243 sizing die to the Atlas and make that happen but may just by a 7-08 die body instead. I have a feeling that a die body wouldn't be the most pleasent thing in the world to take HSS to, perhaps even Cobalt.
 
I may not be following this correctly .
This is to use a mandrell and instead of using the mandrell die.

I have a sinclair 308 mandrell on back order and a sinclair mandrell die.

The lee collet not being used can just have the collet removed.

But the expander is 305 and I got the Sinclair ordered at 306.
 
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Snuby642 said:
I may not be following this correctly .
This is to use a mandrell and instead of using the mandrell die.

I have a sinclair 308 mandrell on back order and a sinclair mandrell die.

The lee collet not being used can just have the collet removed.

But the expander is 305 and I got the Sinclair ordered at 306.

Dont know how accurate I could remove .001, have done it on expander buttons .
Click to expand...

Lee shows a PN for a .3035 pin but not a .305 one in their under sized mandrels. According to their web site the standard mandrel is .3055

You may be able to do something like that with a shear tool in a lathe (after annealing then re-hardening when you're done cutting unless you were using carbide) but I would think you'd be talking about a piece of ground rod honestly.
 
First of all as usual I was thinking backwards, so I removed the last stupid sentance from my post.

I measured the pin in the collet die again and got .305 but my calipers only go to .0005 so that's ok.

With fc gmm brass the result from the fls die is .003 nt. I was wanting to get to the magic .002 nt to get an extra 500 yards out of it.

Lol

Really because .002 nt seems to be the most popular standard here on the hide and done with a mandrell floating. That .003 nt is measuring neck before and after seating bullets.

I don't mind going to the extra step for my sons 308 that shoots fgmm factory rounds just below 3/4 moa occasionally but speed and es and sd is poor.

I am practicing to beat it with these latest rounds loaded with cfe223 to add a little heat under the 168 smk's.

He is supposed to group / chrono these this evening and I told him to watch primers ect carefully.
 
FL sizing without expander followed by Lee collet would work but you will also be working your brass more than you want to. I use a Redding body die to bump 2-3thou then Lee collet for 1.5-2thou neck tension with great results.
 
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If you remove the collet and just use expander I dont understand how it would work brass more?
 
I believe the object was to remove expander in fl die.
Remove collet from collet neck sizing die and leave the epanding mandrell in that.

Or I am lost again.
 
I don't see why the collet die needs disassembly the mandrel is the same size all the way up. I don't take mine apart.

Never noticed the 308 was .0025 and 6.5 and 7 are .002.
 
Well mandrell then.

Wanting intent not tiny details.

Not tring to argue.

So for the moment my mandrell and expander are the same size.

Will I still get a benefit from the separate process due to the free floating?
 
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I do the Collet die & then Body die. I don't think it makes much difference, but I do know that my Remington Custom Shop 40XBKS likes this. Not much difference in my 700 Hart barrel using bushing dies or collet dies, but it shows up in the 40XBKS. I wrote this down years ago on which to use first. I can't remember where I read it , I don't know if it was German Salizar's articles or what, but I do have a note in my die box reminding me which to use first.

Runout is low. I did buy a separate undersized mandrel to use depending on the brass. I was fortunate to have a lifetime supply of free, once fired brass from Police bolt guns. Federal, Winchester and Hornady. One of the perks in the job.

I found one of my AR-15 SPR .223 Wylde barrels likes the collet / body die routine.

I think the Collet / body die is a lower cost alternative to bushing dies and make ammunition just as accurate.

The other plus is using the Body die to repair under sized / shoulder bumped loaded ammo.
 
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Dumb question, I took my calipers and measured the outer case wall before and after seating bullets. I was getting 1 thousandth with a Nosler Custom Competition. Should I be looking to order the under sized Lee Mandrel? By their specs it's 2 thousandths smaller. From what I've been reading I'm probably short on neck tension. I was also running un-annealed brass if that makes a difference (more spring back.)
 
Try adjusting your die. I get more neck tension by screwing in the Lee collet die.
 
You should also measure the thickness of your case neck to determine more accurate neck tension. Most case neck thickness measures .0015 , but I came across some measure .0018. Always a good practice anneal after 2 firing.
 
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Dave62677 said:
Lee collet die is way underrated. You hardly hear people talk about it because it doesn't have the fancy name of "Bushing/ Micrometer /Competition"
Click to expand...
Im proud of my Lee Collet dies. They're fantastic. They're always my final size step. I'll full length size to where is bumps the shoulder about .002" then run it through the LCD to set my desired final neck tension. Anneal and trim every 3rd firing. Easy cheesy. My buddies that have all the micrometer, competition, etc dies were surprised how my ammo is just as accurate as theirs.
 
Dave62677 said:
You should also measure the thickness of your case neck to determine more accurate neck tension. Most case neck thickness measures .0015 , but I came across some measure .0018. Always a good practice anneal after 2 firing.
Click to expand...

Isn’t the benefit of a Lee Collet die that it indexes off of the inside diameter and makes the case wall thickness irrelevant?

I use a Redding body die and Lee Collet. It was measurably more concentric than my Redding bushing dies.

I agree with the above that you can somewhat increase neck tension if you screw down a little more. I recently did a run of 500x where the neck wasn’t quite tight enough and had to run them all back through after screwing the die down another 1/8 turn.
 
The thicker of the case wall will generate more tension than a thinner one even they both 0.001 under.
 
I need to read all this again... Twice...

Are you guys using a different size full length die? Like using a 308 FL die with no expander to size 7-08? If so what basis do you use for choosing the correct incorrect FL die?

Or only using something like the redding body only die for that caliber? And then using the collet die?

Or using a normal FL sizing die with no expander that will shrink the neck way down and then using the lee collet die to open it back up because it does something better than the ball?

I'm lost trying to understand what the process and benefit here is sorry... Someone catch the slow kid up please lol
 
PlinkIt said:
I need to read all this again... Twice...

Are you guys using a different size full length die? Like using a 308 FL die with no expander to size 7-08? If so what basis do you use for choosing the correct incorrect FL die?

Or only using something like the redding body only die for that caliber? And then using the collet die?

Or using a normal FL sizing die with no expander that will shrink the neck way down and then using the lee collet die to open it back up because it does something better than the ball?

I'm lost trying to understand what the process and benefit here is sorry... Someone catch the slow kid up please lol
Click to expand...

The most common practice most in this thread are using and recommending is first use a Redding body die and second use a Lee collet neck die.
I don't personally use this process since I get no more than .0015" max indicated run out on loaded ammo using a Redding Type S FL Bushing die but I also turn my necks from the start.
 
You can send 2 fireformed cases and bullets of your choice to Lee, they can custom a Collet Dies for you. $70.00

you can also request the mandrel size.

$70.00 is a small price to pay for Lee custom collet die
 
Thanks. Lee must have just shipped a production run because they're now in stock everywhere. They've been OOS for months.
 
This.
“Or only using something like the redding body only die for that caliber? And then using the collet die?”
 
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