Making 7mm-08 Remington brass from 243 Win or 308 Win?

[mbonner]

Finding 7-08 brass hard to obtain, so neck up 243 or neck down 308. Probably need to anneal the necks first
right.
Mike

 

[K-C]

I have just been converting 308Win recently. Cases come up a few thou short, but after first firing, they are about the right length...

 

[mbonner]

Do you anneal and use the 7mm-08 die with the decapping pin out?
Mike

 

[Beaumont]

Finding 7-08 brass hard to obtain, so neck up 243 or neck down 308. Probably need to anneal the necks first
right.
Mike

If you are using new brass there is no need to anneal as the necks will be soft enough still. I am doing the same with 308 and 243 new brass as 7-08 is a hard find although Cabelas in Winnipeg has the Nosler 7-08 brass on the shelf.

 

[Cleftwynd]

I use 308 brass all the time for my 7mm08, once fired or new have never had to anneal them.

 

[mbonner]

Yes, thanks, but could you please outline the methods you use for converting to 7mm-08 from 243 and 308?
If you want a big bore rifle get a 9.3x57 from Tradeex, brass convert from 8mm Mauser and cheap fun, low recoil,especially with cast bullets, fine for deer.
Bits of Pieces in Delta can rechamber to 9.3x62.
Mike

 

[Ganderite]

I make 7-08 from 308. I just lube the 308 case, as normal, and full length size it in a 7-08 die. Does not feel much different, in terms of effort on the handle. I do not anneal cases before or after.

 

[elkhuntr]

Sizing up from 243 is a bit tougher but possible. Suggest using a threaded FL decap style like RCBS because the lee die could slip when used in this way. Be sure to Lube inside the neck on each case because the expander will be pushed though the throat of the brass to expand it. Check trim length. Sizing down is preferred over up in normal circumstances. Do not expect great runout until after fire forming. Works fine with once fired. But I have annealed 5x fired when sizing up to ensure split cases are minimized and this could be beneficial for sizing down as well. Would only consider annealing if I wanted to use my norma/lapua brass for such a project. My 2c.

 

[Mystic Precision]

STart with 308 to avoid donuts.

Necking up 243 almost always creates donuts at the base of the neck which are a royal PITA to get rid of.

With the 308, you can typically do it in 1 pass of a sizing die or body die. Outside neck turn, size so it nice a concentric, go have fun.

If starting with thick neck brass like Lapua, definitely a good idea to outside neck turn before sizing down... make your life WAAAAYY easier.

Jerry

 

[c-fbmi]

You can also just fireform 243 in your 7-08 and no it doesn't hurt the rifle one little bit. As everyone says it's just easier to use 308, one pass through the FL sizer die and voila....7-08, nothing to it and I have never had to thin necks from 308 either. I made all my 7-08 from new W-W 308 brass before I found some 7-08 brass.........then I used all my new 7-08 W-W brass to make 260 Rem.......can't trust a single headstamp in my loading room LOL........most of my 9.3X62 says 35 Whelen on it and most of my 35 Whelen says 30-06 on it, all my 300 Wby says 300 H&H and all my 340 Wby says 375 H&H and so on, and so on, and so on, Oh ya and all my 375 Ruger says 300 Win Mag on it too......

 

[H4831]

You can also just fireform 243 in your 7-08 and no it doesn't hurt the rifle one little bit. As everyone says it's just easier to use 308,

I had this in early in this thread, just shoot 243 ammo in your 7-08 and you have a perfect chamber fitting case, just requiring neck sizing.
BUT, for some reason my post was removed. Better luck on your post!
Bruce

 

[mbonner]

Fireforming 243 brass with pistol powder and cornmeal with a wax cap, or shooting factory 243 in the 7-08, Bruce?
Mike

 

[yodave]

You can also just fireform 243 in your 7-08 and no it doesn't hurt the rifle one little bit. As everyone says it's just easier to use 308,

I had this in early in this thread, just shoot 243 ammo in your 7-08 and you have a perfect chamber fitting case, just requiring neck sizing.
BUT, for some reason my post was removed. Better luck on your post!
Bruce

OP started 2 threads, maybe he wanted a better easier way then pointed out in the first thread.............

check your neck clearance when sizing 308 down to 7mm, some 308 win brass will be to thick to allow clearance in your chamber and necks may need to be turned. To check this measure the outside diameter of a fired case, if your loaded case is smaller in the neck by at least 3 thou your good to go. Tight necks will cause higher pressures

 

[K-C]

I make 7-08 from 308. I just lube the 308 case, as normal, and full length size it in a 7-08 die. Does not feel much different, in terms of effort on the handle. I do not anneal cases before or after.

^^^^ same here - using Lee Die set ^^^^

 

[Neilm]

Been doing it for years. made 7-08 260 300savage 250 savage & 243. all from ww brass. The only one I had to neck turn were the 243's

 

[H4831]

Fireforming 243 brass with pistol powder and cornmeal with a wax cap, or shooting factory 243 in the 7-08, Bruce?
Mike

Shoot regular loaded 243 ammo in the 7-08.
They will be a perfectly fire formed, then just size the neck down, for reloading.
Bruce

 

[g-manz35]

OP started 2 threads, maybe he wanted a better easier way then pointed out in the first thread.............

check your neck clearance when sizing 308 down to 7mm, some 308 win brass will be to thick to allow clearance in your chamber and necks may need to be turned. To check this measure the outside diameter of a fired case, if your loaded case is smaller in the neck by at least 3 thou your good to go. Tight necks will cause higher pressures

I wondered about this. I find the Fed 308 brass has a thick neck compared to other brass I use. I usually give the loaded 7mm-08 rounds a check to make sure they are not over spec. NO problems so far, but have not tried it with Fed yet.