When I got my first 7mm-08 (Rem M-788), back in '82 (I think) I used LC72 Military brass without reaming or turning the necks and had no problems!
The case volume is less with the military cases!
Back at that time, there wasn't "the Internet" and all of the information that one can pick up there! So, I just loaded them, with less powder, for the brass thickness!
I don't load "HOT", so, that probably worked for me also!
I have since then, switched to 7mm-08 brass!

I don't think that the turners or reamers for the neck jobs are very expensive! I also don't think that it takes a rocket scientist to operate them. I've never done it, so maybe someone else can jump in here!

Good luck;

fbf:

I'm doing that exact thing right now. Chuck White is correct in that the 7-08 f.l. die will take the 308 case down successfully. The next step is to determine that you have enough neck clearance in the chamber of your rifle. Usually the 308 cases will thicken during the necking down process. For my rifle I am going to have to turn the case necks on the necked down Lapua brass. You need to measure the neck diameter of one of the fired winchester cases that you already have. Then you need to seat a bullet in one of the necked down 308 cases. I would say that there needs to be .004 or more of difference between the 2. In the case of my rifle the fired Winchester brass measures .315. The necked down 308 brass with a Nosler bullet seated in it also measures .315. With that scenario there would be NO room for the case neck to expand and pressures would be extremely high on firing a loaded round. I'm going to take about .002 off the case neck. That will clean them up nicely and give the loaded round a neck diameter of .311. That should result in a safe neck clearance. You can take more off if you want. I wouldn't get the necks too thin though. Anything less than about .012 thick in case necks starts to get a little fragile in a hunting rifle.

knobmtn

I borrowed a .308 case (Lapua) from a friend and ran it through my 7mm-08 die. The neck is too thick to fit my chamber without turning and I'm not sure I want to go that route yet. I also emptied a factory .243 case (Winchester) and necked it up in my 7mm-08 die. It fit in my chamber fine. When I measured case capacity, the .243 case held 48.0 grains of water with a bullet seated, while my Winchester 7mm-08 cases (sized, unfired) hold 45.3 grains. Are the .243 cases safe to reload?

Thanks for all the replys.

How do you know that the neck is too thick for your chamber? In order to determine that, you would have to load a dummy round with a 7mm bullet seated in the resized case and try it. If you simply tried to insert the resized case without a bullet seated and you found that the bolt wouldn't close on it, then the necks may (or may not) be fine and your problem may lie with some other dimension of the resized brass.

In my experience, it is extremely uncommon for brass reduced only "one" caliber to have neck walls that are too thick for the typical factory chamber (which is generally rather oversized).

I was not clear in my previous post, I seated a bullet to create a dummy round with both the .308 case and the .243 case. The .308 case would only close in the chamber with a large amount of force exerted on the bolt handle .

My reloaded necked down 308 case neck is the same size as a fired 7mm-08 case neck also. I decided to order a neck turner from Midway and take the plunge into a new area of reloading. The Lapua brass looks so much better just sitting in the box, the necks are already annealed, flash holes are perfect, very high quality.

The chamber of my rifle must be cut pretty close to specs to not want to accept the dummy round.

I was a little perplexed about the increased case capacity of the .243 case necked up compared to my 7mm-08 & the 308 case. I don't have a SAMMI chart available but shouldn't the pressure max be close to the same among those calibers? Just seems like a lot of difference (3 grains).

You hard chambering is probably due to the bump at the shoulder not a tight neck. Try sizing the case 2 or 3 times without pulling the expander back through the neck. Just size, raise the handle a little spin the case 90� and size again. Make sure the shell holder is touching the die bottom. Then seat a bullet and check. I have sized many 30/06 cases down to 25/06 with no problems.
Ed

I downsize 308 and 7/08 Winchester brass all the time to 260 Rem, as Remington brass is always my second choice.

I choose these two calibers for brass as I don't own or shoot either. I do shoot 243 tho, so that is why I don't use it.

For the 308, I always size it in the 260 die without the expander ball in the die. Then I resize it with a neck sizing die to bring it back to 6.5 bore.

For the 7/08, I just size it in the 260 die and load it up.

cheers and good shooting
seafire