Hybrid '06/.303 Lee Neck Sizer

[sundog]

Die body from either, collar from '06 with hole expanded enough to accomodate the .303 mandrel and collet from either one that works best.

Idea is to work the '06 neck less squeezing down to .309/.310 instead of .305. Using a boolit diameter of .312 it should hold firmly without crimping. Mandrel could be trimmed down a little if needed.

It looks like the parts would accommodate it. Anyone tried this?

[geargnasher]

I haven't tried exactly that, I think the .303 mandrel might be too short for the decapping pin to pilot in the flash hole?

My trick is to hone out a Lee .'06 FL die in the neck to size just enough for two thousandths neck tension with .311" (throat sized) boolits without the expander, and to install an EZ-Expander stem from a Lee .303 British FL die to "kiss" the case neck open another half-thousandth. That way no matter if it's fireformed brass or range pickup brass being sized for the first time it all comes out the same as far as neck tension is concerned.

Two suggestions I'd offer with your setup: Compress the collet fully and hone the base of the neck area out so that it essentially leaves fireformed brass unsized at that point for better centering in the chamber, and add some taper to the sharp angle at the shoulder of the mandrel so it has an easier time opening up smaller case necks.

Gear

[sundog]

Here's what we are working with ('06 left, .303 right):

http://castboolits.gunloads.com/imagehosting/55507ffc66ebbf8.jpg

Last night I ran a 5/16" (0.3125") bit through the '06 collar and cleaned it up with crocus. The mandrel from the .303 die is a nice fit in it with a film of Mobile 1 on it just in the collar area. I reassembled the '06 die with the '06 collett and collar and the [.309] mandrel from the .303 die.

I sized a few discarded '06 brass that had been culled from stuff I am currently using for military bolt matches in an 03A3. Those pieces of brass had been neck turned and fired many times. They sized just fine. I checked them with a few #301s that had already been sized and checked at .311. They look like they will be a nice snug fit in the neck when loaded. A 314299 at .312 would work really good. Next step will be to actually load some and shoot them. Loading and range report to follow....

Observations about the die parts. Mandrels are the same length, .305 and .309. I suspect, but did not check, that the mandrel in 7.7 Jap is the same as the .303. Case length is taken care of by the length of the collett and collar as evidenced in the pic above.

[Pepe Ray]

Sundog;
This is an idea that I have NOT attempted as yet. BUT
because there is no drag on the neck (Lee FCollet die.) Why can we not simply enlarge the mandrel with a wrap of the metal tape as used in Beageling a mold.
FYC
Pepe Ray

[geargnasher]

Good to know, Sundog. Another Lee product that works like Legos!

Gear

[sundog]

I thought about the aluminium tape thing. Ought to be worth a try. But, the hole in the collar would still have to adjusted to accommodate the increased diameter. Good substitute if a desired mandrell size was not readily available. Case mouth would have to be at least the size of the taped mandrel or it might tear the tape - just thinkin'.

Legos..., I like that.

[sundog]

Well, I prepped 20 314299 at .312 with FWFL and Gator checks. Then I prepped 20 (neck turned) LCNM many times fired with the hybrid neck sizer. I loaded them last night over my goto military bolt match load of 21.0/4227. The base of the GC just barely enters the case mouth, no flaring required to start the boolit. I seated them to a depth such that the 03A3 in which they will be fired the boolit is barely kissed -- 3.285". The base of the boolit is almost down to the should neck junction. Nice snug fit, boolit cannot be turned by hand. Rolled on a flat surface, no wobble. So, this Saturday after high power I plan on testing them. So far, so good.

[jonk]

It would save a step, but I'm fine with just using my M die in .311 and being done with it; let us know how they shoot though; I would try the aluminum tape routine to see how that does without hesitation.

[HangFireW8]

Die body from either, collar from '06 with hole expanded enough to accomodate the .303 mandrel and collet from either one that works best.

Idea is to work the '06 neck less squeezing down to .309/.310 instead of .305. Using a boolit diameter of .312 it should hold firmly without crimping. Mandrel could be trimmed down a little if needed.

It looks like the parts would accommodate it. Anyone tried this?

Sounds good and cheap, but getting that hole expanded properly could be challenging for some of us without good machining equipment.

I accomplished the same thing with a Redding "S" 30/06 die, larger neck bushing and a Buckshot-made tapered sizer ball on the decapping pin. Most of the time the sizer ball just barely drags on the way out, which is good, as those things often drag a tighter case neck out of concentricity.

If it doesn't drag, I know the case hasn't been sized enough, is thin, is just resistant to sizing, or too large a neck bushing.

If it drags a lot, I know the case has been sized too much, is too thick, too small a neck bushing, or sizes too easily.

With this setup it is much easier to maintain case concentricity, plus I get longer brass life, both goals of yours as well, I'm sure.

HF

[sundog]

Saturday's targets, each a little over 2" at 100 yards. Dispersion to outer extremities is on me.

I plan on shooting this load, prepped this way at the next military bolt match.

http://castboolits.gunloads.com/imagehosting/555090002b55fa5.jpg

http://castboolits.gunloads.com/imagehosting/555090002bb3f5c.jpg

[sundog]

HF, read post #3. Used a 5/16 twist drill in a cordless hand drill to enlarge the hole. Didn't need much and cleaned up quite easily.

[HangFireW8]

HF, read post #3. Used a 5/16 twist drill in a cordless hand drill to enlarge the hole. Didn't need much and cleaned up quite easily.

I see. You have a steadier hand than me!

HF

[felix]

I see. You have a steadier hand than me! ... HF


Yeah, he does! That's why Sundog shoots all my validation rounds for whatever, like any gun or ammo. My days are labeled charging tin can capability only, and sometimes that is even questionable. ... felix

[Shiloh]

Been my arrangement since I started shooting cast. Ordered the oversize mandrel from LEE. I size my 314299 to .312. just kisses the parting lines.

Shiloh

[sundog]

Update from Saturday's military bolt match. Windy. Very windy. I shot the load as described above and shot a 294/300-11X. Won the match.

I am in the process of getting a bunch of these ready for matches over the winter, and if they work out like Saturday past, I plan on loading a lot large enough to take me through next year's state match.

[BeeMan]

Well done sundog, on the new technique and the match. Especially impressive given the wind Saturday.

BeeMan

[fatelvis]

Idea is to work the '06 neck less squeezing down to .309/.310 instead of .305.
This is where the Redding bushing dies shine


I'm going to use my .311" M die to expand the neck, then use my Redding FS "S style" bushing die to size everything down to where it should be.

[sundog]

We had another match yesterday, and this new technique (using the mandrel from the 303 die in the '06 die) has proved it's worth.

295/300-9X. Won both group matches and all three score matches. All things being equal, cartridge prep makes a difference. On any given day, any of us who shoot this match can win, but turning in consistent scores will always put a shooter in contention.

Now, I need an 'over sized' mandrel for the .303 Brit...

I did make a change though. Sight adjustment on the 03A3 is, at best, course. To help get the right combination of POA/POI I upped the charge to 22.0/4227 and added a 1/4 sheet TP. Voila. Down one notch and hold a sliver of daylight. Magic.

Match time was about 50dF with wind variable 5-15. As the match progressed it got darker. Not the best conditions for getting decent sight picture.

NOE 314299 is a really fine boolit, and it is a pleasure using the 'Made in USA' 4 cavity mould.

[Doc Highwall]

sundog, what are you using for a rifle and are you position shooting?

[sundog]

Doc, 50 record rounds off the bench with any 'as issued' military bolt gun, i.e, Mauser, Springfield, SMLE, Nagant, Arisaka, etc. I shoot a CMP 03A3. If I didn't know better, I'd swear that rifle was brand new in the cosmoline when I received it. It now has well over 6K boolits through it (never touched jacketed) and getting better every match.

The match is shot on SR21 @ 100 yards, 2 10-round groups, and 3 10-round scores. Fun, casual match and good company.

[felix]

Corky, the 22-250 shoots it best with very light finger seating using 15g N120 Lyman 225646. I don't use the load much because of transport problems to the river/mountain. The only time I load at the range is at your house. What is strange is the chamber is at neck standard at 253 and the necks turned for 244. Obviously the load is optimum on these days when the performance duplicates itself. ... felix

[Doc Highwall]

sundog, sounds like an easy and fun match.

[Sonnypie]

I have pondered this, but my Lee collet die set seems to be working better than my shootin eye does anymore. :-?
I measured the mandrel in mine once and I believe it was .3055-.306. But the spring back opened it up around .308. And my sized .3105 cast bullets fit good. I've been using a zero jump seating position. (Single shot, bench rest)

But I'm really glad to see you stuck your foot in the water and actually did the modification and it's a success.
Maybe I missed it, but did you put the .303 mandrel in the modified 30-06 collet?
(I don't have .303 dies to try it with. But thought about getting a .303 mandrel as a way to "adjust" the neck sizing.)
All of the 30 caliber mandrels seem to be .3055. But the .303 brit appears to be more "lead friendly". And at a mere $4, is easily worth buying.
And did you use the .303 collet sleeve (and mandrel) in the 30-06 collet die? (OK, now we're up to $8. But I don't need a die set)

Different mandrels are available through Lee Precision.
30-06 mandrel. .3055 (http://leeprecision.com/decap-mandrel-.3055.html)
303 British mandrel. .3085 (http://leeprecision.com/decap-mandrel-.3085.html)
http://leeprecision.com/collet-sleeve-303b.html

My interest is because I do not crimp with my cast bullets. Nor do I bell or use an M-die. I found the gas check would allow for the bullet to enter the case mouth fine. And the rounds chamber fine just neck sized.

Also, I do a size-turn-size-turn-size, turning the case about 120° between each sizing to get rid of the collet lines. Seems to make them nicer appearing anyway.
OK, so I'm anal. ;)

Edit in: I don't decap with the collet die. I decap before cleaning the brass. So the decapping pin is merely a guide of sorts. And a flash hole checker. (SS pins from the tumbler occasionally are lodged in the flash hole)

[sundog]

Sonnypie, I used all the 30-06 parts EXCEPT the mandrel. The '06 mandrel was replaced by the .303 mandrel. The hole in the '06 collar has to be relieved enough for the .303 mandrel to fit.

If you look at the picture you will see the collar and collets in the two dies are different lengths.