From .308 down to .243: is this doable at home?

[Jason M]

I've got a .243 that I am about to begin hand loading for. I will have about 40 casings from factory ammo to load, but I see reloadable boxer primes .308 casings all over the range a lot.

Is it possible for me to just gather up .308 casings and heat up the neck/shoulder area and run them through a .243 resizing die and case trim any excessive length?

-Jason

 

[cpttango30]

Yes. I would load them on the lighter side to fireform them the first go round but after that work them up to the speed and accuracy you want.

You might need to turn the necks but I never had to when necking down 308 brass.

 

[snuffy]

Is it possible for me to just gather up .308 casings and heat up the neck/shoulder area and run them through a .243 resizing die and case trim any excessive length?

The way this reads to me indicates you think you need to run them through the .243 die hot? NOPE! When forming from one caliber to another, it's done cold. You MAY need to anneal them after forming, then you need to heat the neck/shoulder area, then cool them quickly.

 

[Strongbad]

As the gentlemen have said, run them through your resizing die, then anneal them.

 

[Walkalong]

Yep, follow snuffy's advise. After all, the .243 started out as a necked down .308. Firefrom with 90% to 95% charges, not light ones.

 

[ranger335v]

Forming .308 into .243 is easy enough. Usually, the new cases will be on the short side but not enough to be concerned with and neck thickness is rarely an issue.

Don't over heat the necks when annealing, getting the metal red hot is far too hot! Just heat the necks until you see a slight blue blush on the shoulder and then drop each one into a bucket of water to prevent annealing the body and head.

I agree about fireforming with 95% charges, less pressure simply won't smooth things out very well.

 

[Jason M]

The way this reads to me indicates you think you need to run them through the .243 die hot? NOPE! When forming from one caliber to another, it's done cold. You MAY need to anneal them after forming, then you need to heat the neck/shoulder area, then cool them quickly.

Most helpful--thanks! Yes, my original assumption was you needed to form them when they are mildly hot (400 degrees or so). Thank you for steering me in the right direction.

Now..once you ram that .308 in the .243 die...just how hard is it to get out? The use of case lube is prudent, I imagine?

 

[Walkalong]

The use of case lube is prudent, I imagine?

Imperial Sizing Die Wax.

Good stuff.

 

[GooseGestapo]

Getting them out isn't hard. Getting them in, and not denting the shoulders or collapsing the shoulder is a little more difficult.

The lube is the key, and use enough, but JUST enough......

Ditto, the Imperial sizing wax.

 

[ranger335v]

It will be a GREAT help if you have or can borrow an intermediate step die to take the necks down in stages. A 7-08 and/or .260 sizer would be perfect.

Anytime we sholve brass into a FL die requires proper case lube or a case puller to remove it later.

 

[243winxb]

sizing 308 to 243 Not worth the trouble

http://www.stevespages.com/page8d.htm The neck of a loaded round should not measure larger than .276" Case trim lenght will we shorter then recommended, causing more throat erosion on firing. Military brass may cause a problem with headspacing. You will also get a donut near the neck shoulder junction with some brass. The expander button may be very hard to remove from the case after sizing, make sure you lube the inside of the neck well.

 

[Jason M]

I was at the range yesterday and scrounged form .308 brass for resizing experiments to .243 when I ran across what I theorize to be a jewel for my plans. I picked up a handful of 7mm-08 casings (I have NO idea why anyone would throw them away). They look a lot closer to .243 with respect to the shoulder angle. I know I won't come by 7mm-08 casings all the time, but I would imagine they are better candidates than .308 brass?

 

[Shawnee]

+1 for "243winxb's" comments.

Home-formed .243 brass is barely - if at all - worth having. Fun enough for a project but new .factory .243 brass is relatively cheap and will give you better load consistancy and longer case and throat life. Not goo unusual to find .243 brass at the ranges either, if not on the ground then for sale cheap.

Have reloaded and shot .243s for years. An absolutely splendid load is the Hornady 87-gr. BTHP over 42 grs. of IMR4350. Bumping the charge to 42.5 grs. often is also great in many rifles. Ditto loading the 100 gr. spitzers with those charges.

Where in "Central Florida" are you ?

 

[Jason M]

Where in "Central Florida" are you ?

Titusville, Florida. It is in Brevard on the east coast.

Thanks for the advice. I would imagine that reformed brass is not the "best", but I was curious to try it. But unfortunately for me, virgin brass is not cheap here. Any retail store or LGS will have it for about $40 per 100. And at $0.40 each, they are more expensive than cheap factory ammunition.

I will be sure to load up some of the 87gr Hornadays you mentioned! I love shooting anything in the 70-90gr range thus far. They work the best with factory ammo. My hand loads will tell the tale on 100gr though.

Have you worked up any good 100gr loads?

 

[Shawnee]

You can try 42grs. and 42.5grs. of IMR4350 with 100-gr. bullets.

Those charges are slightly below max. so work up to them. The listed max. per Hornady's "Vol II" reloading manual for their 100gr. spire point is 43.3 grains (of IMR4350).
That manual is from 1973.

I lived in Winter Haven and Lake Wales (due East of Vero) for about 15 years (until 2006). Been on your wildlife drive at Titusville (Blackhawk?) three or four times.

Good Luck !

 

[PCJim]

I've reloaded .243 also, using 100gr Nosler Partitions over 40.0gr IMR4350. This load used to be below max for 4350 powder, but is now at or over max depending upon the manual referenced. Lyman tops out at 39.5gr, Speer #14 at 41.5. The Speer #8 & #10 manuals (ancient, but still with valuable info) both maxed out at 42.0 grains.

As to casings, I always bought factory ammo on sale and just reloaded it. Didn't want to mess around with becomming a psudo wildcatter......

Good Luck.

 

[Jason M]

I lived in Winter Haven and Lake Wales (due East of Vero) for about 15 years (until 2006). Been on your wildlife drive at Titusville (Blackhawk?) three or four times.

Black Point? I go duck hunting out on that refuge every year.

I will probably start the 100gr load from 39 or 39.5 and work up, loading 10 rounds each of the different powder charges in 1/2 grain increments. Most .243 barrels seem to be 1:10", so I would imagine I can work up nice loads for nearly any grainage of .243 bulet.