Lee collet neck size die

[longbow]

A word of advice. I bought a Lee neck sizer for .303 British because my RCBS dies were sizing necks to very optimistic SAAMI specs of 0.311"/0.312" bullets. I am loading o.315"/0.316" boolits to suit large throat and groove diameters. I had backed off the dies to just neck size because the chambers are so sloppy I found I was pushing the shoulder back about 1/16"! Even then the die was sizing the necks so small they resized boolits as they were seated. Way too much neck tension! A neck sized to hold a 0.311" bullets is pretty tight on ACWW at 0.316" so not only was it hard on boolits, the brass was being heavily overworked.

Back to the Lee neck sizer... I bought a Lee neck sizer to address this and found that the mandrel in the neck sizer also made for undersize necks. I made a mandrel to give me 0.313" inside the neck after sizing and that worked well. However, I think it was Larry Gibson that said you don't need the mandrel at all. The collet can be adjusted to squeeze down without a mandrel.

Regardless, if you have military chambers they may be larger than spec so you may want to either make a suitable mandrel or set the collet to size larger rather than squeezing to the mandrel to minimize working the brass at the neck. Okay, re-reading you have a Ruger American Ranch Rifle coming so that should be to SAAMI spec chamber so not an issue.

I like my Lee collet sizer. It works well for me.

Longbow

[cupajoe]

I was concerned about the finished neck diameter. I contacted Lee and they verified that the die is in fact designed for .308 bullets. I believe the cost for a custom mandrel is $10 plus shipping. If the brass
neck thickness is consistent, looks like sizing without the mandrel may be the way to go.

[44magLeo]

I load for the 7.62x54R. My Lee die set is the three die set. FL size with a .308 expander rod. the dead length seater and the FCD.
When I ordered this set I also got the 303 British expander. The .308 expander is .307 id diameter. The 303 British is .309 in diameter. This is ok for most jacketed bullets but not for the .314 cast I use.
Lee can make a collet neck size die for $70 for a two die set. If I did I would order two mandrels. One at .310 for the .311 and .312 bullets. one at .313 for cast.
I have a Lyman 310 set I built for the 7.62x54R. The neck sizer in that sizes the necks to .310 ID. When I use the .311 Lyman M expander I only get the step to do anything to the brass. The minor size of that expander is .3095.
This works fine with the .311 and .312 jacketed bullets.
For cast I use an NOE expander of .317x .313. to use in my Lee universal expander die. This should give me enough neck tension. If not the collet crimp die will fix that.
Using the collet neck sizer as Larry Gibson suggests may be the trick. Adjust it so it squeezes the necks to what ever diameter you want may be a bit tricky but it sounds very doable.
May have to try that on one of the cartridges I have the collet neck size die for.
Leo

[megasupermagnum]

This is one area I think Larry Gibson, if those are actually his words, is incorrect. In an ideal world, with perfect brass, with a perfect die, and a perfect press. Then yeah, you could probably get away with a collet and no mandrel to size the necks. Since no press is perfect, the collets are not perfect, and brass is ANYTHING but perfect, you will get inconsistent neck tension sizing that way. Maybe it's not enough to matter to some people, but that's the way it is.

Spend the $10 on a mandrel, or make your own. Any other way is a fools errand. The die is genius, you squeeze brass around a rod, and it produces very consistent (and round!) inside neck dimensions. Don't try and out think it.

[Three44s]

If I have learned one thing while being a member of this forum for a dozen years or so, it is that if member Larry Gibson says something works it can be taken to the bank.

I would suspect that one wants to be cautious as one advances the collet die sans a mandrel further against the shell holder. The net result of a lack of caution would probably lead to sticking the collet in the top of the die head. Also lubricating the collet enough is likely a good practice without a mandrel.

Remember, the focus of this forum is that of shooting cast boolits and as such they are typically sized larger than j word slugs. The subject arises often that case necks sized too small and stuffed with larger cast boolits runs contrary to keeping those boolits as sized. Simply put, a soft tender cast slug needs to be seated in case neck that is large enough to accept it without undersizing it and wrecking it’s potential for accuracy.

Now if someone wants to make their own larger mandrel, I say go for it. If Lee makes one large enough for this purpose, again go for it. But as I recall Lee sells mandrel perhaps a thou up or down? If that is all then most cast boolits are still going to be roughed up.

It is intuitive that trying a collet die without it’s mandrel so as to minimally resize the case necks to avoid additionally resizing a cast slug thus damaging it.

Three44s

[megasupermagnum]

Lee will make a custom mandrel in any size you ask for, for $10.

[Three44s]

I see that they offer undersized and oversized for a number of listed cartridges. They also offer for other non listed ones pending contacting them.

Good to know, thanks

Three44s

[W.R.Buchanan]

I use one of mine on a .303 Enfield. Most loads are reduced cast loads, and I have not FL sized my cases in over eight reloadings. Accuracy is very good but I can’t say it is better than FL sizing. It is far easier due to the lack of a lube requirement.



.

On cartridges like the .303 Brit which headspaces off the rim and Enfield Rifles are known to have generous chambers the Lee Collet Die doesn't set the shoulder back like F/L sizing does.

If you F/L size .303 cases you'll get 2-3 reloadings before case separation occurs simply because every time you fire the round the case has to expand forward to fill the longer chamber, and the brass stretches most right in front of the base web of the case, and that is where the case separates. Kind of a pain to remove the case from the chamber after that happens. Best to just avoid that problem altogether.

The Lee Collet Die solves this problem by only squeezing the Case Mouth down on a mandrel that is smaller than a bullet. It also squeezes the case neck from all sides simultaneously so concentricity is not affected.

Notice how the shoulder on the reloaded round on the left bears no resemblance to the unfired factory round on the right? It was fired in my 1943 BSA #4 Mk1 made during WWII. Chambers were made this way so ammo made anywhere in the Empire would run in any Enfield Rifle. The round headspaces on the rim so anything that happens forward of that is meaningless, and nobody was concerned with reloading these.

This is why you don't F/L size these cases, and the Lee Die affects the case the least amount of all methods available..

I use them on all my bottleneck cases except .223's which are mass loaded and usually a one way trip.

Randy

[tazman]

Very impressive and educational picture.

[Three44s]

Randy,

Your picture is very timely. I do not do the 303 Brit but the husband of one of my SIL’s has a Santa Barbra in it and he bought some foreign ammo that will not chamber in it. Another husband of another SIL was just there at the Santa Barbra owner’s place and came over to visit us afterwards before driving (4 hrs) home.

We were wondering if the rifle was chambered for something else. Now after reading your post I wonder if it is just chambered “tight”.

This may require a chamber cast. I never have done one but it is not rocket science.

Three44s

[W.R.Buchanan]

Commercially made guns in .303 British like Ruger #1's and British Sporting Rifles would probably have chambers made more to the SAAMI specified dimensions.

My guns was originally a Military gun but slightly reworked by Parker Hale after the war into an economical Sporting Rifle. It was a "Standard Sporter" and cost $65. I have another that was a "Deluxe Sporter" $75 which had the buggered portion of the muzzle cut off (buggered from over cleaning) and a new PH front sight soldered on. It is a "Long Branch" Canadian Made gun and had the weird 2 groove barrel so it got bored and rechambered by JES to 35-303. I need to finish that gun pretty soon.

Randy

[cupajoe]

The collet dies arrived and I had a chance to mess with them. I took the die apart and polished the outside of the collet with 2000 grit wet or dry to take some of the rough edges off. I cleaned everything up and put a little moly grease on the outside of the fingers of the collet and reassembled it. I set the die as Lee recommends and it sized as advertised. I don't remember what the outside diameter of the neck was after sizing but, as discussed, it would be way tight on a .313 bullet. The neck O.D. with a .310 jacketed bullet seated is .334. I backed the die out and started lowering the die a little at a time and set it to size the O.D. to .332 when my rockchucker cammed over so the mandrel only serves to deprime the case and as a sorta case guide. After I fireform the brass I will reset the dies to size the necks for .313 bullets.

[44magLeo]

I bought a spam can of military surplus 7.62x54 ammo. This ammo has a Berdan primed Brass case.
I plan on modifying this brass to take boxer primers.
I took the de-capping rod out of my Lee F/L size die. I then sized 20 pieces of this brass.
I measured the ID and OD of the necks. OD was .322, ID was .300. Over the 20 cases it didn't vary much, less than .002. With this brass it seems a bit tight even for using .308 dia. bullets.
As we all know die makers know that brass can vary in neck thickness and allow for that ion the size of the die.
On this brass it leaves me with .011 thick neck walls.
On the collet type die by sizing against a mandrel you reduce how much you size the necks. In this case If I had a .313 mandrel I would reduce the amount I size these neck buy .013.
This will extend case life.
This is stuff most of us have read of course, some even know from experience. These measurements do show how much things are done differently.
I have done a bit more research on getting Lee to Make a collet die for my 7.62x54R. On their web site they do make a single die. They don't list a price. They want a couple fired cases from your rifle and sample bullets. That way they can make the die to exactly match your chamber. I think even at $70 it is not a bad deal. I never bought custom dies before but imagine they cost a lot more than that.
Some may ask what this has to do with a 303 British. The 7.62x54R has some of the same issues as the 303 British. bore size does vary and chambers can be a bit loose. In mine I think my chamber is a bit snug.
I bought some once fired brass for my 7.62x54R and most was either hard to chamber or wouldn't chamber. After F/L sizing some was still stiff to chamber.
I used a sharpie to color the whole case to see where the case was tight in my rifle. Color rubbed off a bit on the shoulder and a bit more just ahead of the rim.
I found a Lyman Shell Sizer. This sizer is like a Lee loader, you pound the case in and out with a mallet.
This sizer has tight dimensions. It squeezes the shoulder and base of the case tighter than the F/L die did. About .001 or .002 smaller. Not much but enough to work. They all chamber just like a factory round does, no resistance to bolt closure.
Now when I fire them in my rifle they should resize ok.
On your 303 Brit you might want to send Lee some cases and bullets and get one of the collet dies cut to match your chamber. Even order a mandrel for each size bullet you load, jacketed and cast.
Leo

[GregLaROCHE]

I started neck sizing because it made good sense to me to do so.

[44magLeo]

longbow, I reread thus thread. I see you have a Collet die, I might call Lee and explain what is happening. They may let you send the die back and they can cut a new collet for the die. They may want a couple fired cases and a couple bullets to test things with.
Leo

[W.R.Buchanan]

On your 303 Brit you might want to send Lee some cases and bullets and get one of the collet dies cut to match your chamber. Even order a mandrel for each size bullet you load, jacketed and cast. Leo

Leo: the Lee Collet Neck Sizing Die doesn't have a "Chamber" that fits the case. The mandrel lines the case up . If you look at the pics of my brass before and after firing you can see that if the die had a interior shape conforming to the unfired case, my fired cases wouldn't go into it. Now on a F/L die then the shoulder would be set back and case life shortened as a result. The whole idea of the Lee Collet Neck Sizing Die is that it doesn't touch the shoulder at all.

Other brands of Neck Sizing Dies do have chamber shaped cavities, and some have interchangeable bushings so you can make the neck any size you want, But they don't have mandrels to get in the way, which brings us back to the point about just backing the Lee Die out and setting it so that it doesn't close the case mouth all the way down on the mandrel. This is the simplest way to deal with larger boolits. Jacketed bullets will size the ID of the neck to whatever they need. Lead Boolits will probably get sized by the smaller case mouth.

Or you can always buy different sized mandrels from Lee as well. I'd try backing the die out first before I spent the money.

Randy

[cupajoe]

Randy, what you described in your last post is exactly what I did. I backed the die out and lowered it until I had the neck O.D. I was looking for. I did use an RCBS lock ring in place of the Lee ring so I have a positive stop to work with.

[Wansingct]

When I got my RPR in 6 Creed I sent in cases and bullets (Hornady 108 ELD-M) to have them cut a neck sizing die. I believe it was a great investment in my reloading for this rifle along with Forester BR dies for 6 Creed. Found out that the neck sizer they cut also pushed the shoulder back .02, just perfect for me and makes it so I don't use the body die any more. Lee now has 6 Creed neck dies that I believe were built around the RPR chamber and 108 ELD.

[MostlyLeverGuns]

I use the Lee Collet Neck Size Die For my Savage 99 .243 Win. Using this die the lightweight rifle will normally group around .75-.8 MOA with 100 gr Sierra flat-base. It is very easy on brass.

[GONRA]

GONRA appreciates the virtues of Necksizing - EXCEPT FOR SEMIAUTOS! Slam Fire Potential! MUST have free (loose) chambering for safety reasons.