Changing 308 Win brass to 243 Win

road.warrior · November 17, 2004, 09:35 AM

Can I use my 243 dies to neck down 308 surplus brass? Is there a
(or multiple) "in between" dies specifically for this process?

Tom Matiska · November 17, 2004, 10:45 AM

I've done it. It is possible. The result is a thick neck that should be turned.

Tom

road.warrior · November 17, 2004, 11:15 AM

Outside neck turned?

Tom Matiska · November 18, 2004, 08:03 AM

I can't speak from experience on the turning. My solution to the problem of thick necks was to simply get some 243 brass and use the 308 brass in the my 308(duh... what was I thinking???) I only trim for length.

One good intro to the subject is:

http://www.realguns.com/Commentary/comar88.htm

Leftoverdj · November 18, 2004, 11:36 AM

It's doable. Some dies and some lots of brass will do it in one pass. Better to use a 7-08 or .260 die as an intermediary. Whether the necks need more attention depends on your rifle and the lot of brass you use. The neck must be a couple of thous smaller than the chamber neck to release the bullet. If it isn't, the neck must be thinned, preferrably by inside neck reaming. If what you have is an outside turner, turn in the .308 or the intermediate step.

Conventional wisdom says to reduce your max charge two grains using reformed military because of the heavier cases.

Bob C · November 18, 2004, 03:03 PM

IMHO this is way more trouble than it's worth. Buying .243 brass is my suggestion.

Whatever method you choose to remove the extra brass from the neck area will be time consuming.

In those earlier days when resizing 30/06 brass was the only way to get .25/06 brass I did a fair amount of this, but not after I could buy the brass.

Leftoverdj · November 18, 2004, 06:47 PM

You might not need to remove any brass from the neck. Depends on your brass and your chamber neck. Worth forming a few to check.

Even neckturning is not much of chore for me. I chuck the Forster rig in a drill press, lube the necks with kerosene on a Q tip, and let the dirll press do the work. It does it fast, too.

I admit being cheap. When a thousand .308 is available for the price of 200 of its relatives, I'll do some reforming.

rustylp · November 18, 2004, 08:08 PM

Ive reloaded for both rounds and it takes some time or a weekend warrior could do somthing like that or just some one who takes pride in there work. im going to suggest buying new brass for both rounds and load them as many time as you feel comfortable. be sure to look at the brass closely, I was just messing around looking over some new winchester rounds that came out off a browing 243 semi auto and I think it could have been worn out. because under a microscope i found a hole near the rim on one case and one great big buldge one on the bottom side of the same case reminds me of a double barrel shotgun i owned as a kid one barrel sodybody messed up and must have got a little snow in it at one point in time. . Im glad i caught myself cause i did reload some of the brass. the rounds were brand new so didnt think a gun would mess them up. i could have been out of a 243 loading new winchester brass from a worn gun

road.warrior · November 19, 2004, 11:12 AM

This was the plan as I can buy once fired 308 brass at 1/10th the
price of new 243 brass. Call me a cheap bastard. I deserve it.

Leftoverdj wrote:
I admit being cheap. When a thousand .308 is available for the price of 200 of its relatives, I'll do some reforming.

rustylp · November 19, 2004, 01:23 PM

I feel ya man. i under stand its easy to make a round. and im no one to judge so keep on loading that good brass

Paul B. · November 19, 2004, 06:46 PM

Raod.W said, "This was the plan as I can buy once fired 308 brass at 1/10th the
price of new 243 brass. Call me a cheap bastard. I deserve it."

Being thrifty is one thing. Being stupid and potentially blowing up a rifle is something else.
I did not notice if this was brought up, but if it was, it still bears repeating.
Measure the neck of a once fired factory .243 round. Then, measure the neck of the .308 case you've converted to .243 after steating a bullet in that case. If that case with the bullet seated is at least .002" smaller than the fired .243 case, you should be OK. Better yet if it's even smaller. That case has to have sufficient room to properly expand at the neck to release the bullet. If it does not, very high pressures and a potential KABOOM.
It's OK to be thrifty, but not at the expense of your safety. You can't grow back missing body parts or eyes.
Paul B.

Leftoverdj · November 19, 2004, 09:17 PM

Paul, you are ignoring brass springback. The neck does need to be a couple of thous smaller than the ID of the chamber neck, but a fired case is no measure of that unless the case neck was annealed dead soft before firing. A chamber cast might be in order, but I generally just load up one of reformed cases with a starting load and have at it. Since I anneal somewhere along the line, that case will give me an accurate reading. Just loading the chamber manually is probably good enough since you can feel resistance if the cartridge is too large, but I am a cautious chap.

Paul Fitz Jones · November 20, 2004, 02:37 AM

And used an inside neck reamer and even went down to 22-250.

Paul

Peter M. Eick · November 20, 2004, 08:55 AM

I had a 308 case get into my 7-08 cases during reloading and I did not catch it. I loaded to my usual load (not hot but nice shooter) and had the primer blow. I think the key components were case neck thickness, very hot day (about 110f) and internal case volume.

Just be very cautious as you do this. Check, double check and proceed carefully.

By the way, I won't buy a 243 because I already have 308 reloads, 7-08 reloads and after this experience, I don't want to make the same mistake. I bought federal gold medal brass for my 308's and I only use Nickled 7-08 cases to avoid the confusion.

road.warrior · November 22, 2004, 11:10 AM

I made sure I did a little at a time so as not to heat the case by working
it too quickly. I did three cases with each in about five steps. I was only
using the 243 FL die. I found it supprising that the neck thickness only
changed by .002 dia (1 thousandth all around) from the size when it was
a 308 case. The loaded round seems to chamber ok.

Another interesting thing was the unloaded case was about .060 too
short. Does anyone see a problem with this (other than not being able
to use a factory crimp die)? I will be shooting it in a Tikka T3.

Paul B.: I understand your concern about the size once loaded and I will
go back and measure before firing. I will compare to my other standard
handloads as well as some factory loads.

November 17, 2004, 09:35 AM	#1
road.warrior Member Join Date: October 22, 2004 Location: Wallyworld, CT Posts: 26	Changing 308 Win brass to 243 Win Can I use my 243 dies to neck down 308 surplus brass? Is there a (or multiple) "in between" dies specifically for this process?

November 18, 2004, 08:08 PM	#8
rustylp Member Join Date: October 5, 2004 Posts: 54	boy thats some work Ive reloaded for both rounds and it takes some time or a weekend warrior could do somthing like that or just some one who takes pride in there work. im going to suggest buying new brass for both rounds and load them as many time as you feel comfortable. be sure to look at the brass closely, I was just messing around looking over some new winchester rounds that came out off a browing 243 semi auto and I think it could have been worn out. because under a microscope i found a hole near the rim on one case and one great big buldge one on the bottom side of the same case reminds me of a double barrel shotgun i owned as a kid one barrel sodybody messed up and must have got a little snow in it at one point in time. . Im glad i caught myself cause i did reload some of the brass. the rounds were brand new so didnt think a gun would mess them up. i could have been out of a 243 loading new winchester brass from a worn gun

November 19, 2004, 01:23 PM	#10
rustylp Member Join Date: October 5, 2004 Posts: 54	its cool do your thing I feel ya man. i under stand its easy to make a round. and im no one to judge so keep on loading that good brass

November 19, 2004, 06:46 PM	#11
Paul B. Senior Member Join Date: March 28, 1999 Location: Tucson, AZ Posts: 3,801	Raod.W said, "This was the plan as I can buy once fired 308 brass at 1/10th the price of new 243 brass. Call me a cheap bastard. I deserve it." Being thrifty is one thing. Being stupid and potentially blowing up a rifle is something else. I did not notice if this was brought up, but if it was, it still bears repeating. Measure the neck of a once fired factory .243 round. Then, measure the neck of the .308 case you've converted to .243 after steating a bullet in that case. If that case with the bullet seated is at least .002" smaller than the fired .243 case, you should be OK. Better yet if it's even smaller. That case has to have sufficient room to properly expand at the neck to release the bullet. If it does not, very high pressures and a potential KABOOM. It's OK to be thrifty, but not at the expense of your safety. You can't grow back missing body parts or eyes. Paul B. __________________ COMPROMISE IS NOT AN OPTION!

November 20, 2004, 02:37 AM	#13
Paul Fitz Jones Senior Member Join Date: June 12, 2002 Location: Sacramento California Posts: 266	I have done it with GI brass And used an inside neck reamer and even went down to 22-250. Paul Last edited by Paul Fitz Jones; November 20, 2004 at 02:38 AM. Reason: addition

November 17, 2004, 10:45 AM	#2
Tom Matiska Senior Member Join Date: April 12, 2000 Location: Wilkes-Barre, Pa Posts: 1,029	I've done it. It is possible. The result is a thick neck that should be turned. Tom

November 17, 2004, 11:15 AM	#3
road.warrior Member Join Date: October 22, 2004 Location: Wallyworld, CT Posts: 26	Outside neck turned?

November 18, 2004, 08:03 AM	#4
Tom Matiska Senior Member Join Date: April 12, 2000 Location: Wilkes-Barre, Pa Posts: 1,029	I can't speak from experience on the turning. My solution to the problem of thick necks was to simply get some 243 brass and use the 308 brass in the my 308(duh... what was I thinking???) I only trim for length. One good intro to the subject is: http://www.realguns.com/Commentary/comar88.htm

November 18, 2004, 11:36 AM	#5
Leftoverdj Senior Member Join Date: October 15, 2004 Posts: 934	It's doable. Some dies and some lots of brass will do it in one pass. Better to use a 7-08 or .260 die as an intermediary. Whether the necks need more attention depends on your rifle and the lot of brass you use. The neck must be a couple of thous smaller than the chamber neck to release the bullet. If it isn't, the neck must be thinned, preferrably by inside neck reaming. If what you have is an outside turner, turn in the .308 or the intermediate step. Conventional wisdom says to reduce your max charge two grains using reformed military because of the heavier cases.

November 18, 2004, 03:03 PM	#6
Bob C Senior Member Join Date: January 1, 1999 Location: St. Louis, MO suburbs Posts: 386	IMHO this is way more trouble than it's worth. Buying .243 brass is my suggestion. Whatever method you choose to remove the extra brass from the neck area will be time consuming. In those earlier days when resizing 30/06 brass was the only way to get .25/06 brass I did a fair amount of this, but not after I could buy the brass.

November 18, 2004, 06:47 PM	#7
Leftoverdj Senior Member Join Date: October 15, 2004 Posts: 934	You might not need to remove any brass from the neck. Depends on your brass and your chamber neck. Worth forming a few to check. Even neckturning is not much of chore for me. I chuck the Forster rig in a drill press, lube the necks with kerosene on a Q tip, and let the dirll press do the work. It does it fast, too. I admit being cheap. When a thousand .308 is available for the price of 200 of its relatives, I'll do some reforming.

November 19, 2004, 11:12 AM	#9
road.warrior Member Join Date: October 22, 2004 Location: Wallyworld, CT Posts: 26	This was the plan as I can buy once fired 308 brass at 1/10th the price of new 243 brass. Call me a cheap bastard. I deserve it. Leftoverdj wrote: I admit being cheap. When a thousand .308 is available for the price of 200 of its relatives, I'll do some reforming.

November 19, 2004, 09:17 PM	#12
Leftoverdj Senior Member Join Date: October 15, 2004 Posts: 934	Paul, you are ignoring brass springback. The neck does need to be a couple of thous smaller than the ID of the chamber neck, but a fired case is no measure of that unless the case neck was annealed dead soft before firing. A chamber cast might be in order, but I generally just load up one of reformed cases with a starting load and have at it. Since I anneal somewhere along the line, that case will give me an accurate reading. Just loading the chamber manually is probably good enough since you can feel resistance if the cartridge is too large, but I am a cautious chap.

November 20, 2004, 08:55 AM	#14
Peter M. Eick Senior Member Join Date: August 3, 1999 Location: Houston, Texas Posts: 2,991	I had a 308 case get into my 7-08 cases during reloading and I did not catch it. I loaded to my usual load (not hot but nice shooter) and had the primer blow. I think the key components were case neck thickness, very hot day (about 110f) and internal case volume. Just be very cautious as you do this. Check, double check and proceed carefully. By the way, I won't buy a 243 because I already have 308 reloads, 7-08 reloads and after this experience, I don't want to make the same mistake. I bought federal gold medal brass for my 308's and I only use Nickled 7-08 cases to avoid the confusion. __________________ 10mm and 357sig, the best things to come along since the 38 super!

November 22, 2004, 11:10 AM	#15
road.warrior Member Join Date: October 22, 2004 Location: Wallyworld, CT Posts: 26	Ok, I resized three of the 308 to 243. I made sure I did a little at a time so as not to heat the case by working it too quickly. I did three cases with each in about five steps. I was only using the 243 FL die. I found it supprising that the neck thickness only changed by .002 dia (1 thousandth all around) from the size when it was a 308 case. The loaded round seems to chamber ok. Another interesting thing was the unloaded case was about .060 too short. Does anyone see a problem with this (other than not being able to use a factory crimp die)? I will be shooting it in a Tikka T3. Paul B.: I understand your concern about the size once loaded and I will go back and measure before firing. I will compare to my other standard handloads as well as some factory loads.