Necking down .308 to .243

[Bennybigbores]

Hi wondering if any one knows the process for necking down .308 to .243 I've got tonnes of .308 brass and never reload it use .243 all the time.

Surely it's not a simple as jamming the .308 into a .243 resizing die, haven't tried it.

Any info be helpful and is it even worth while or should I keep it simple and keep shooting off factory highland for the brass?

[MeccaOz]

Never done it it either mate, but it's my understanding it is a several die process, taking it down bit by bit. Annealing the case might also be the go.

[Bennybigbores]

Pass, next topic?

[Gwion]

Dunno. I'd just deprime and clean the 308 brass and flog it off as once fired, then buy some new 243 brass. Less frigging about.

[Bennybigbores]

Would do but no .243 brass in my area tried 4 gunshops and no good, have to resort to firing off factory, but highland have the best brass surprisingly and they're cheap. On that topic any body want to buy legitimate once fired brass mostly federal and highland ?

[teekay0]

Ben
If you aren't going to reload .308 sell the brass, there is always .243 brass available .
I can understand resizing 308 to 07-08 and .260 because its hard to get brass for them . but not .243.
Not worth the trouble in IMO
tk0

[Gwion]

Would do but no .243 brass in my area tried 4 gunshops and no good, have to resort to firing off factory, but highland have the best brass surprisingly and they're cheap. On that topic any body want to buy legitimate once fired brass mostly federal and highland ?

I am looking for some, but only in 223

[Gwion]

Hornady and Lapua brass in 243 available online. Not cheap but it's available. Hornady $59 for 50 and Lapua $145 for 100 or there abouts.

[Lorgar]

Surely it's not a simple as jamming the .308 into a .243 resizing die, haven't tried it. Any info be helpful...

Actually that's pretty much it...

I have pictures on here from doing it somewhere. Let me find...

[Lorgar]

Here you go.



Left case is factory .243 Winchester.

Right case is .308 Winchester necked down to .243.

Single pass in press with RCBS dies.

If you can do an intermediate step like .308 > 7mm > .243 that's great, but you can get away without it.

Don't forget the lube.

[joojoobeans]

That's what she....

Sorry

[big d]

Yeah mate , I have done a lot over the years . I start with one pass through a Lee full length size die, then I have an original simplex full length die that you use with a bench vice to press the case in. I then trim the case to minimum case lengh and they chamber just like a bought one. They do get a slight indent in the shoulder but that flattens out upon firing. Then I usually just neck size them four or five times before full length is required. Don't forget to lube them , not heavy though. Worth the effort of you have lots of brass.

[Lorgar]

They do get a slight indent in the shoulder but that flattens out upon firing.

Yep, I got the same.

Fired out fine the same as well.

[duncan61]

Maybe annealing the brass to a soft red then letting cool naturally would help out.If you get the brass too hot and quench it will soften to much and the necks will collapse.I have a ,243 and would try to make brass if I was having trouble sourcing new or used brass.Dont tell anyone but we do this sport for fun and making something work is fun

[wrenchman]

7mm-08 is a round thats got some popularity here i dont no what you gain but i would have to read up on it

[Bills Shed]

Maybe annealing the brass to a soft red then letting cool naturally would help out.If you get the brass too hot and quench it will soften to much and the necks will collapse.I have a ,243 and would try to make brass if I was having trouble sourcing new or used brass.Dont tell anyone but we do this sport for fun and making something work is fun

Yes Annealing will help the process if the brass is too hard. If it has just been fired once there should be no requirement. On the temp side yep, a dull red in a dark room is all that you will need. Ref the quenching or letting it cool naturally, it is irrelevant. It is the temp that is important (for BRASS) not the cooling rate. I quench my jackets just to stop oxidation for ease of clean up. When annealing necks I also flick them into a bucket of water just for safety but it makes no difference to the hardness.
Bill

[bladeracer]

Maybe annealing the brass to a soft red then letting cool naturally would help out.If you get the brass too hot and quench it will soften to much and the necks will collapse.I have a ,243 and would try to make brass if I was having trouble sourcing new or used brass.Dont tell anyone but we do this sport for fun and making something work is fun

Yes Annealing will help the process if the brass is too hard. If it has just been fired once there should be no requirement. On the temp side yep, a dull red in a dark room is all that you will need. Ref the quenching or letting it cool naturally, it is irrelevant. It is the temp that is important (for BRASS) not the cooling rate. I quench my jackets just to stop oxidation for ease of clean up. When annealing necks I also flick them into a bucket of water just for safety but it makes no difference to the hardness.
Bill

I've always believed the quench is purely to get the heat out of the brass as quickly as possible to avoid accidentally annealing the case head.

[Bills Shed]

Yep the quenching will stop the the heat flow to the case head and that is required. Letting it cool in air could lead to heat transfer and so case head hardness issues. After re-reading that post I see that I worded it poorly.

When annealing JACKETS is does not matter if they are cooled in air or water. I take cases and turn them into jackets!

Cases to be reloaded need to be quenched in water to stop heat transfer.

Bill

[Wm.Traynor]

A question has occurred to me that might be relevant
Do the necks have to be inside-reamed after reforming? Wondering if the re-sizing process thickens the neck and does it make bullet seating difficult or increase pressures?

[brett1868]

A few notes on annealing
1. There is no metallurgical purpose for quenching brass.
2. 650F-750F is the min / max temp required to anneal the necks otherwise pointless.
3. >450F at the base destroys the case.
4. Don't anneal pistol cases with a flame, it's dangerous due to the small case size and risk of softening the base.
5. Brass isn't the best of heat conductors, there isn't enough residual heat in the neck / shoulder to soak down and ruin the base once the heat source is removed unless you've over heated the shoulder. So the only reason to quench would be to cool the brass to enable handling.
6. In the absence of a proper temp indicator a dull red in a darked room is reasonably close.
7. Heat must be applied consistently around the neck / shoulder. Ideally the case should rotate in the flame from a controlled distance.

Tempilaq paints can be purchased online which "Melt" at a specific temperature. I use the 650F on the necks and 450F on the bases when setting up the Bench Source for new cases to calibrate the timer.

[Gwion]

Conducting any heat treatment purely on colour is a questionable practice. You say 'dull red', but what that looks like to you is completely different to how i will interperate it.

Mucking around with approximates might be ok if your hardening a knife in spring steel, the margin of error isn't going to blow up in your face... annealing cartridge cases, on the other hand......

Not saying some of you guys aren't getting it right with experience; this is just a word of warning to anyone thinking of trying it for the first time.

I say get some tempilaq, as Brett suggests.

[Lorgar]

7mm-08 is a round thats got some popularity here i dont no what you gain but i would have to read up on it

It's a bit more niche here in my experience.

I'm a fan though, I had a .308 and .243 a while back and have since replaced both with a 7mm-08 Tikka.

Great all purpose hunting cartridge for here in Australia, won't matter in the US but it's about the perfect spot to cover the game hunting laws here,

Mine shoots 0.4 MOA so is more than accurate enough for some target fun when I get to the range too.

[Lorgar]

A question has occurred to me that might be relevant
Do the necks have to be inside-reamed after reforming? Wondering if the re-sizing process thickens the neck and does it make bullet seating difficult or increase pressures?

The necks will thicken, you're not removing material by necking down the brass so it has to go somewhere as you reduce the neck diameter.

I've never bothered to measure or turn/ream the necks as I'm not chasing the kind of accuracy that requires fanatical case prep, and reloading is just a chore for me these days, not fun, so I wouldn't do it 'just because'.

Seating projectiles in .308 cases necked down to .243 you could feel it was tight as you raised the ram of the press, but didn't require excessive force and I never had one fail to seat.

Seating pills in cases necked down to 7mm I'd get the occasional tight one, but in most you wouldn't notice a difference at all. After I got my 7mm-08 I necked down about 400 308 cases and have reloaded them all several times without any problem at all.

[Wm.Traynor]

Thanks Lorgar

[Bills Shed]

Conducting any heat treatment purely on colour is a questionable practice. You say 'dull red', but what that looks like to you is completely different to how i will interperate it.

I say get some tempilaq, as Brett suggests.

Totally agree, I did just that for the first couple of hundred cases. After that my consistency got pretty good. Still use it every now and then though.

Bill

[bladeracer]

A question has occurred to me that might be relevant
Do the necks have to be inside-reamed after reforming? Wondering if the re-sizing process thickens the neck and does it make bullet seating difficult or increase pressures?

If you're necking down then the neck will get thicker. As long as it's not thicker than the gap between the bullet and the chamber throat then there's no problem.
If it's too thick to allow the neck to open up and release the bullet then pressure will increase significantly.
I doubt .308 down to .243 would be a problem with most brass but it's always best to check clearance before shooting the brass and turn the outside down if required.

[bladeracer]

7mm-08 is a round thats got some popularity here i dont no what you gain but i would have to read up on it

It's a bit more niche here in my experience.

I'm a fan though, I had a .308 and .243 a while back and have since replaced both with a 7mm-08 Tikka.

Great all purpose hunting cartridge for here in Australia, won't matter in the US but it's about the perfect spot to cover the game hunting laws here,

Mine shoots 0.4 MOA so is more than accurate enough for some target fun when I get to the range too.

I'm with you, 7mm-08 is pretty amazing.
Only downside is you can't run the really heavy hitters that you can in .308.
Heaviest .284" bullet I'm aware of is 220gn from Alco, but it requires a minimum 7" twist.
http://www.alcobullets.com/7mm-bullets/
Generally, you're probably not going to use anything heavier than 162gn for hunting.

[Lorgar]

Heavier pills is no concern for me at all.

I have two loads for mine. 120gr Ballistic Tips and 140gr Ballistic Tips.

120gr for when I'm on a friends property expecting foxes and fallow, and 140gr for the forest when expecting the larger deer species (and the odd goat).

I'm yet to find the deer that can shrug off a 140gr hunting bullet to the chest inside 200m.

If you really wanted to run something heavier you could use 150gr BT's, 160gr Accubond's, 154gr Interbond's, 162gr and 175gr Interlock's, 162gr SST's etc. etc.

With a quality projectile and taking sensible shots 140gr - 160gr is plenty.

To be frank, those 220gr Alco bullets seem ridiculous to me. If someone wanted to shoot 220gr bullets I think they've bought the wrong rifle going with a 7mm.

I note as well that the BC figures they quote along side most (all?) of those 7mm bullets are stated with velocities that exceed the ADI and other powder makers maximum load muzzle velocity by 150 - 200 fps so aren't even practical.

They're just about high Ballistic Coefficient bragging rights as far as I can tell

If I was building a long-range hunting or match rifle (where BC actually mattered), a 7mm Rem Mag with 180gr Berger's or Sierra's would do me just fine.