Neck Up .308 Win to 7.7 Japanese

[Mad Jack]

I want to load a 7.7 Japanese bullet into a .308 Winchester brass. These will be used in a Arisaka Type 99 that was re chambered to .308 Win.

If I use a 7.7 Japanese expander ball in my .308 die, would I work the brass too much? I tend to think so. The .308 is shorter than 7.7 Japanese so 7.7mm neck sizing die would need to be shortened?

Any ideas?

Thanks!!!

[Maven]

Actually Lyman's Rifle Neck Expanding "M" Die, part no. 7349005 may be the better way.

[Mad Jack]

Actually Lyman's Rifle Neck Expanding "M" Die, part no. 7349005 may be the better way.

Quick question on "M" dies.

How does the "M" die size the neck after it was necked up and fired? Seems it misses the step of sizing the neck down before re-expanding to proper size?

Curious.

[Mad Jack]

Maybe my last reply was confusing?

I think I know where my thinking went wrong. I looked the Lyman die as an sizer / expander. If it is only an expander I still have my problem of sizing a 7.7mm neck to a .308 win case. I am missing the sizing die to use with that expander.

Thinking out loud here.

[WebMonkey]

i use a lee 303 british expander in my lee .308 winchester sizing die to load lead projectiles easier.
i also 'back out' my neck die a hair so it doesn't 'squeeze' the neck as much.

i don't know if that would be large enough diameter for you or not.

good luck,
'monkey

[Maven]

Without a FL or neck sizing die, the M die won't work. However, it is possible to get a neck- or FL sizing die with a larger expander ball. E.g., most die manufacturers include 2 for resizing the 7.62 x 39mm cartridge. Given their excellent reputation for customer service, purchase a used RCBS sizing die, then a call to their customer service desk for a .311" expander ball should do the trick. The M die is used after FL or even neck sizing to expand and slightly flare the case neck and mouth so you don't distort cast bullets when seating them.

[Der Gebirgsjager]

Anneal the .308 necks before expanding the first time.

[Eddie2002]

Deleted last two posts, didn't pick up on the fact that the Arisaka was rechambered to .308.

[Mad Jack]

Thanks everyone. I do have dies for and reload .308 win. I was worried, maybe about nothing, that sizing first in .308 sizing die results in working the brass more than needed if I pull a .311 ball instead of the stock .308 ball.. I think ideally I should have my .308 sizing die opened at the neck to 7.7 Japanese and get a expander ball for 7.7 too. I use a FL die backed out so I only size 80% or so of the neck. I don't want to bump the shoulder back yet.

[Eddie2002]

I've been loading for 7.7x58 and have used both a .308 and a .311 inside expander for J word bullets with no problems. The only difference I've noticed is more neck tension for the smaller inside expander which might help if you are only bumping down the neck and not FL resizing every time.

[EDG]

1. Excessive working would come from an under sizer die neck, not the expander fatter expander.

2. You can use normal .308 dies with a .310 or .311 expander depending on if you are using a .311 or .312 bullet. I have checked the necks of a lot of .308, 30-06 .303, 7.7 and 7.65 sizing dies and they are all very close to the same diameter. Some of the dies intended for the .308 may have a neck larger than 7.7 and .303 dies so they might work the brass less than a 7.7 die
3. If you want to tune you neck diameter, Redding makes a .308 Type S bushing neck die. With the correct bushing for the application this die will work on about 40 cartridges from .219 Zipper up to 8X57.


I want to load a 7.7 Japanese bullet into a .308 Winchester brass. These will be used in a Arisaka Type 99 that was re chambered to .308 Win.

If I use a 7.7 Japanese expander ball in my .308 die, would I work the brass too much? I tend to think so. The .308 is shorter than 7.7 Japanese so 7.7mm neck sizing die would need to be shortened?

Any ideas?

Thanks!!!

[Mad Jack]

Thanks everyone. I was worried over nothing. I appreciate the advice and will start with getting a .311 expander for my .308 sizing die. I'm trying to get a touch more accuracy out of that rifle.

[screwcutter]

Mad Jack,
How was this Arisaka Type 99 re chambered to .308? Just curious as the the 7.7 is about a 1/4" longer than the .308 Win.
mr

[ipopum]

No doubt they set the barrel back and the used a 308 WIN reamer to form the chamber. I have one like that.

[nicholst55]

If you want to do it the elegant way, buy a Forster .308 FL die, load a few test rounds, then mike the outside of the necks. Then have Forster hone the die out to size the necks to your desired daimeter. They only charge a few bucks for this service, and it will totally eliminate excessive sizing and expanding of your brass.

[Mr Humble]

EDG has the cost effective solution. Buy the Redding bushing die.

[pugjunga123]

I'd use an M die then just neck size to .311 after the first firing.

[leadman]

Have you checked the size of the bore on this? All 3 of mine are .313" groove to groove so I shoot .314" boolits. If you buy a Lee Collett die for 308 Win you can change the mandrel inside it to a larger one. Lee does sell these separate. This way the brass will not get sized down too far.

[Eddie2002]

Going from .308 to .311 really isn't that much of an expansion, the RCBS die set for 7.62x54r has both size expanders. I would look for military .308 brass just because it is more robust and is thicker in the neck. It's not like it is a rare case, in fact I'm a little jealous, just spent a few hours resizing 40 pieces of 30-06 brass down to 7.7x58 for my Arisakas. Running .308 brass would so much easier and cheaper.

[Texas by God]

Going from .308 to .311 really isn't that much of an expansion, the RCBS die set for 7.62x54r has both size expanders. I would look for military .308 brass just because it is more robust and is thicker in the neck. It's not like it is a rare case, in fact I'm a little jealous, just spent a few hours resizing 40 pieces of 30-06 brass down to 7.7x58 for my Arisakas. Running .308 brass would so much easier and cheaper.
I used to just run 8x57 brass through my 7.7x58 sizer then load as normal. Easy. Best, Thomas.

[Eddie2002]

8x57 is the way to go for an Arisaka but there isn't a lot to be found as range brass. I'll even use berdan primed 8x57 brass since I've two brcks of berdan primers. 30-06 is still common enough but a bit more work reworking it.

[leadman]

I also use 8X57 brass to make 7.7X58. You can not even tell you are resizing the case as there are no special operations to do. The 7X57 has a longer neck and shorter body than the 8X57 so if one wants use this brass for making 7.7X58 a false shoulder will have to be made.

[EDG]

In my area 8X57 brass is not commonly found in large quantities.
Since I have a number of 8X57 rifles I leave 8X57 brass as is for those rifles.

Large quantities of 30-06 commercial, 30-06 military and .270 are easy to find and are somewhere between free and very cheap.

I make most of my brass out of 30-06 military if I can since it has no caliber marking.
Next I will use .270 brass since I do not own a .270.

I have to cut off and anneal both .30-06 and .270 but that is little problem since the brass is very easy to obtain.